Dissertations / Theses: 'Carbon stock on soil'

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Pereira, Osvaldo José Ribeiro. "Mapping soil organic carbon storage in deep soil horizons of Amazonian Podzols." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-14062016-113621/.

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The Podzols of the world are divided into intra-zonal and zonal according to then location. Zonal Podzols are typical for boreal and taiga zone associated to climate conditions. Intra-zonal podzols are not necessarily limited by climate and are typical for mineral poor substrates. The Intra-zonal Podzols of the Brazilian Amazon cover important surfaces of the upper Amazon basin. Their formation is attributed to perched groundwater associated to organic matter and metals accumulations in reducing/acidic environments. Podzols have a great capacity of storing important amounts of soil organic carbon in deep thick spodic horizons (Bh), in soil depths ranging from 1.5 to 5m. Previous research concerning the soil carbon stock in Amazon soils have not taken into account the deep carbon stock (below 1 m soil depth) of Podzols. Given this, the main goal of this research was to quantify and to map the soil organic carbon stock in the region of Rio Negro basin, considering the carbon stored in the first soil meter as well as the carbon stored in deep soil horizons up to 3m. The amount of soil organic carbon stored in soils of Rio Negro basin was evaluated in different map scales, from local surveys, to the scale of the basin. High spatial and spectral resolution remote sensing images were necessary in order to map the soil types of the studied areas and to estimate the soil carbon stock in local and regional scale. Therefore, a multi-sensor analysis was applied with the aim of generating a series of biophysical attributes that can be indirectly related to lateral variation of soil types. The soil organic carbon stock was also estimated for the area of the Brazilian portion of the Rio Negro basin, based on geostatistical analysis (multiple regression kriging), remote sensing images and legacy data. We observed that Podzols store an average carbon stock of 18 kg C m-2 on the first soil meter. Similar amount was observed in adjacent soils (mainly Ferralsols and Acrisols) with an average carbon stock of 15 kg C m-2. However if we take into account a 3 m soil depth, the amount of carbon stored in Podzols is significantly higher with values ranging from 55 kg C m-2 to 82 kg C m-2, which is higher than the one stored in adjacent soils (18 kg C m-2 to 25 kg C m-2). Given this, the amount of carbon stored in deep soil horizons of Podzols should be considered as an important carbon reservoir, face a scenario of global climate change
Os Espodossolos podem ser divididos em zonais e intrazonais de acordo com área onde ocorrem. Os Espodossolos zonais são típicos de áreas boreais e taiga, delimitados por condições climáticas. Já os intrazonais não são condicionados pelo clima. Os Espodossolo intrazonais brasileiros ocupam uma grande extensão da alta bacia amazônica, tendo sua formação atribuída à ocorrência de lençóis freáticos suspensos associados à acumulação de complexos organometálicos em ambientes ácidos redutores. Esses solos tem a capacidade de estocar grandes quantidades de carbono orgânico em horizontes espódicos profundos (Bh), em profundidades que podem variar de 1,5m a 5m. Pesquisas atuais relacionadas ao estoque de carbono em solos amazônicos, não levam em consideração os estoques encontrados no horizonte Bh (abaixo de 1m de profundidade). Sendo assim, o principal objetivo da presente pesquisa foi quantificar e mapear o estoque de carbono nos solos da bacia do Rio Negro, tendo-se em vista aquele estocado no primeiro metro de solo, bem como o carbono armazenado em até 3m de profundidade. A quantidade de carbono orgânico estocado nos solos da bacia do Rio Negro foi estimada em diferentes escalas de mapeamento, desde mapas locais até a escala da bacia do Rio Negro. Imagens de sensoriamento remoto de alta resolução espacial e espectral foram essenciais para viabilizar o mapeamento dos solos nas áreas estudadas e permitir a estimativa do estoque de carbono. Uma análise multisensor foi adotada buscando-se gerar informações biofísicas indiretamente associadas à variação lateral dos tipos de solo. Após o mapeamento do estoque de carbono em escala regional, partiu-se para a estimativa na escala da bacia do Rio Negro, com base em análise geoestatística (krigagem por regressão linear), imagens de sensoriamento remoto e base de dados de domínio público. Após o mapeamento do estoque de carbono na escala da bacia, constatou-se que os Espodossolos têm um estoque médio de 18 kg C m-2, para 1m de profundidade, valor similar ao observado em solos adjacentes (Latossolos e Argissolos) os quais tem um estoque de 15 kg C m-2. Quando são considerados os estoques profundos, até 3m, a quantidade de carbono dos Espodossolos é superior com valores variando de 55 kg C m-2 a 82 kg C m-2. Estoque relativamente maior que aquele observado em solos adjacentes para esta profundidade (18 kg C m-2 a 25 kg C m-2). Portanto, o estoque de carbono profundo dos Espodossolos, não deve ser negligenciado levando-se em conta cenários futuros de mudanças climáticas

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Tifafi, Marwa. "Different soil study tools to better understand the dynamics of carbon in soils at different spatial scales, from a single soil profile to the global scale." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLV021/document.

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Les sols sont la principale composantede l’écosystème terrestre et le plus grand réservoir de carbone organique sur Terre, étant très réactifs aux perturbations humaines et aux changements climatiques. Malgré leur importance dans les réservoirs de carbone, la dynamique du carbone des sols est une source importante d'incertitudes pour les prévisions climatiques futures. Le but de la thèse était d'explorer différents aspects d’études du carbone des sols (mesures expérimentales, modélisation et évaluation de bases de données) à différentes échelles spatiales (de l'échelle d'un profil à l'échelle globale). Nous avons souligné que l'estimation des stocks globaux de carbone du sol est encore assez incertaine.Par conséquent le rôle du carbone des sols dans la dynamique du climat devient l'une des principales incertitudes dans les modèles du système terrestre utilisés pour prédire les changements climatiques futurs. La deuxième partie de la thèse porte sur la présentation d'une nouvelle version du modèle IPSL-Land Surface appelé ORCHIDEE-SOM, intégrant la dynamique du 14C dans le sol. Plusieurs tests effectués supposent que les améliorations du modèle devraient se focaliser davantage sur une paramétrisation dépendante de la profondeur,principalement pour la diffusion, afin d'améliorer la représentation du cycle global du carbone dans les modèles de surface terrestre, contribuant ainsi à contraindre les prédictions futures du réchauffement climatique
Soils are the major components ofthe terrestrial ecosystems and the largest organiccarbon reservoir on Earth, being very reactive tohuman disturbance and climate change. Despiteits importance within the carbon reservoirs, soilcarbon dynamics is an important source ofuncertainties for future climate predictions. Theaim of the thesis was to explore different aspectsof soil carbon studies (Experimentalmeasurements, modeling, and databaseevaluation) at different spatial scales (from thescale of a profile to the global scale). Wehighlighted that the estimation of the global soilcarbon stocks is still quite uncertain.Consequently, the role of soil carbon in theclimate dynamics becomes one of the majoruncertainties in the Earth system models (ESMs)used to predict future climate change. Thesecond part of thesis deals with the presentationof a new version of the IPSL-Land SurfaceModel called ORCHIDEE-SOM, incorporatingthe 14C dynamics in the soil. Several tests doneassume that model improvements should focusmore on a depth dependent parameterization,mainly for the diffusion, in order to improve therepresentation of the global carbon cycle inLand Surface Models, thus helping to constrainthe predictions of the future soil organic carbonresponse to global warming

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Veronesi, Fabio. "3D advance mapping of soil properties." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7848.

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Soil is extremely important for providing food, biomass and raw materials, water and nutrient storage; supporting biodiversity and providing foundations for man-made structures. However, its health is threatened by human activities, which can greatly affect the potential of soils to fulfil their functions and, consequently, result in environmental, economic and social damage. These issues require the characterisation of the impact and spatial extent of the problems. This can be achieved through the creation of detailed and comprehensive soil maps that describe both the spatial and vertical variability of key soil properties. Detailed three-dimensional (3D) digital soil maps can be readily used and embedded into environmental models. Three-dimensional soil mapping is not a new concept. However, only with the recent development of more powerful computers has it become feasible to undertake such data processing. Common techniques to estimate soil properties in the three-dimensional space include geostatistical interpolation, or a combination of depth functions and geostatistics. However, these two methods are both partially flawed. Geostatistical interpolation and kriging in particular, estimate soil properties in unsampled locations using a weighted average of the nearby observations. In order to produce the best possible estimate, this form of interpolation minimises the variance of each weighted average, thus decreasing the standard deviation of the estimates, compared to the soil observations. This appears as a smoothing effect on the data and, as a consequence, kriging interpolation is not reliable when the dataset is not sampled with a sampling designs optimised for geostatistics. Depth function approaches, as they are generally applied in literature, implement a spline regression of the soil profile data that aims to better describe the changes of the soil properties with depth. Subsequently, the spline is resampled at determined depths and, for each of these depths, a bi-dimensional (2D) geostatistical interpolation is performed. Consequently, the 3D soil model is a combination of a series of bi-dimensional slices. This approach can effectively decrease or eliminate any smoothing issues, but the way in which the model is created, by combining several 2D horizontal slices, can potentially lead to erroneous estimations. The fact that the geostatistical interpolation is performed in 2D implies that an unsampled location is estimated only by considering values at the same depth, thus excluding the vertical variability from the mapping, and potentially undermining the accuracy of the method. For these reasons, the literature review identified a clear need for developing, a new method for accurately estimating soil properties in 3D – the target of this research, The method studied in this thesis explores the concept of soil specific depth functions, which are simple mathematical equations, chosen for their ability to describe the general profile pattern of a soil dataset. This way, fitting the depth function to a particular sample becomes a diagnostic tool. If the pattern shown in a particular soil profile is dissimilar to the average pattern described by the depth function, it means that in that region there are localised changes in the soil profiles, and these can be identified from the goodness of fit of the function. This way, areas where soil properties have a homogeneous profile pattern can be easily identified and the depth function can be changed accordingly. The application of this new mapping technique is based on the geostatistical interpolation of the depth function coefficients across the study area. Subsequently, the equation is solved for each interpolated location to create a 3D lattice of soil properties estimations. For this way of mapping, this new methodology was denoted as top-down mapping method. The methodology was assessed through three case studies, where the top-down mapping method was developed, tested, and validated. Three datasets of diverse soil properties and at different spatial extents were selected. The results were validated primarily using cross-validation and, when possible, by comparing the estimates with independently sampled datasets (independent validation). In addition, the results were compared with estimates obtained using established literature methods, such as 3D kriging interpolation and the spline approach, in order to define some basic rule of application. The results indicate that the top-down mapping method can be used in circumstances where the soil profiles present a pattern that can be described by a function with maximum three coefficients. If this condition is met, as it was with key soil properties during the research, the top-down mapping method can be used for obtaining reliable estimates at different spatial extents.

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Longbottom, Todd L. M. S. "Climatic and topographic controls on soil carbon storage and dynamics in the Indian Himalaya: Potential carbon cycle and climate change feedbacks." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342106746.

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Ferreira, Tiago Lima. "Relações causais em sistemas de produção agrícola e agropecuária." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/178354.

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O presente trabalho teve por objetivo compreender sistemas de produção agrícola e agropecuária a campo pela avaliação da diversidade, funcionalidade e dinâmica espaço-temporal de espécies, assim como pelo padrão de variação da qualidade do solo e dos fatores que a determinam. Para isso, foi avaliado na “Agropecuária Guajuvira” localizada no município de São Miguel das Missões – RS quatro sistemas conservacionistas de produção. Foram eles: 1- sistema agrícola tradicional, representando a sucessão soja/trigo e soja/aveia preta amplamente praticada na região; 2- Sistema agrícola irrigado, semelhante ao anterior, mas, com recente inserção de milho no verão; 3- Sistema integrado de produção agropecuária 1, representando a sucessão soja/pastejo de azevém e 4- Sistema integrado de produção agropecuária 2, representando um sistema misto por apresentar alterações na composição de espécies no inverno pela sucessão soja/aveia preta pastejada, soja/aveia preta não pastejada e soja/nabo forrageiro/trigo O estoque de carbono (EC), estabilidade de agregados do solo (EAS) e índice de manejo de carbono (IMC) foram escolhidos como indicadores da qualidade sistêmica do solo. Seus padrões de variação foram compreendidos pela integração de atributos químicos, físicos e biológicos do solo, assim como por variáveis de paisagem inerentes às unidades amostrais. Os fatores que caracterizaram os sistemas de produção e o uso da análise de caminhos permitiram um maior entendimento de sistemas complexos de produção agrícola e agropecuária a campo.
The aim of this research was to understand agricultural and integrated crop-livestock production systems by the species diversity, functionality and spatial-temporal dynamics evaluation, as well as of the variation pattern of soil quality and factors that determine then. For this, four no-tillage production systems were evaluated on the "Agropecuária Guajuvira" located in São Miguel das Missões county in southern Brazil. The production systems were: 1- Traditional agricultural system, representing the succession soybean/wheat and soybean/black oat widely practiced in the region; 2- Irrigated agricultural system, similar to the previous one, but, with recent insertion of corn in the summer; 3 - Integrated crop-livestock system 1, representing the succession of soybean /grazed ryegrass and 4 - Integrated crop-livestock system 2, representing a mixed system due changes in species composition during winter by succession of soybean/grazed black oat, soybean/no-grazed black oat and soybean/forage radish/wheat The carbon stock (CS), soil aggregate stability (SAS) and carbon management index (CMI) were chosen as systemic soil quality indicators. Their variation patterns were understood by the integration of chemical, physical and biological soil attributes, as well as by landscape variables inherent to the sampling units. The factors that characterized the production systems and the path analysis utilization allowed a greater understanding of complex agricultural and integrated crop-livestock production systems in the field.

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Ros, Mesa Ignacio. "Stochastic modelling of soil carbon stocks under different land uses: a case study in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97097.

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Thesis (MSc)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: The research was conducted in the Kwa-Zulu Natal midlands, South Africa. The vertical distribution of soil organic carbon (SOC) stocks were successfully predicted by stochastic exponential models developed for the three main land uses in the area, which are farmlands, forestry plantations and grasslands. These models, in combination with regular surface sampling, may be used for monitoring SOC dynamics in the area and mapping SOC stocks. Bulk density measurements are needed in combination with SOC content (%wt) to calculate such SOC stocks. Considering the disadvantages of bulk density sampling and measurement, an effort was made to determine if one of the commonly-used existing stochastic models could be used to successfully predict bulk densities for soils with known texture and SOC content to replace direct measurements, taking into account that different managements might affect final results. Statistica software was used to correlate the Saxton & Rawls model predictions and associated regressions with measured values for the study area. A clear distribution trend was achieved using Statistica and the correlations were fair with r2 values close to 0.5 for individual regressions and substantially higher for area averages. However, considering the depth-stratified averages and correcting for the effects of particle density changes for soils with high soil organic matter, high correlations for 2 of the 3 studied land uses were achieved (r2 values of 0.99 and 0.81 in forests and grasslands respectively). Therefore, although Saxton and Rawls (2006) predictions of bulk density may be used, it is preferable to conduct direct bulk density determinations. The proposed models to calculate the vertical distribution of SOC would substantially reduce the cost of soil carbon inventories to 1m soil depth in the study area by limiting observations to the soil surface. Triplicate 5cm-deep soil core samples would be collected at the soil surface per observation point for determination of ρb (bulk density) and Corg (organic carbon). On average, the accuracy of the normalized depth-distribution model is rather high for grasslands and forests/forest plantations (R2 = 0.98), but somewhat lower for cultivated lands (R2 = 0.96) due to mixing of the plough layer to cultivation depth. Carbon stocks to 1m depth were calculated as an integral of the normalized exponential distribution, multiplied by the value of Corg observed at the soil surface and expressed on volume basis as carbon density (Cv, kg∙m-3). The resulting stock assessment was compared to the observed values using piece-integration for sampled depth increments to give SOC stocks on an area basis (kg∙m-2). The estimated prediction error on average was 1.2 (9%) and 3.7 kg∙m-2 (21.6%) in grasslands and forests respectively, while for cultivated lands the error was 1.3 kg.m-2 (9.5%). Further improvement to reduce these errors may be achieved by introducing the soil type as variable and grouping the functions by soil type rather than land uses. The results of this work were presented at the seminar of the department of Soil Science, Stellenbosch University (Ros et al., 2014), the combined congress of the South African Soil Science, Horticulture and Agronomy societies (Rozanov et al., 2015), the First Global Soil Map conference, France (Wiese et al., 2013), the 20th International Congress of Soil Science, Korea (Wiese et al. 2014) and were submitted for publication in Geoderma special issue dedicated to digital soil mapping of soil organic carbon following the presentation at the 20th ICSS, Korea (Wiese et al., 2014).
AFRIKAANSE OPSOMMING: Hierdie navorsing is in die Kwa-Zulu Natalse middellande van Suid-Afrika gedoen. Die vertikale verspreiding van grondorganiese koolstof (GOK) is suksesvol voorspel deur middel van stogastiese eksponensiële modelle wat vir die drie hoof landsgebruike ontwikkel is. In kombinasie met roetine monsterneming by die grondoppervlak kan hierdie modelle suksesvol aangewend word vir die monitering van GOK dinamika in die studiegebied, sowel as kartering van GOK voorraad. Bulkdigtheidsmetings word tesame met GOK inhoud (%massa) benodig om die GOK voorraad te bereken. Weens die nadele van monsterneming vir bulkdigtheidsbepalings is ‘n poging aangewend om te bepaal of een van die mees algemeen gebruikte bestaande stogastiese modelle (Saxton & Rawls 2006) gebruik kan word om die bulkdigtheid van gronde suksesvol vanaf tekstuur en GOK inhoud te voorspel en sodoende direkte metings te vervang. Statistica sagteware is gebruik om die voorspellings met behulp van die Saxton & Rawls modelle en gevolglike regressies met gemete waardes vanuit die studiegebied te korreleer en ‘n duidelike verspreidingstendens is hierdeur opgelewer. Die korrelasies vir individuele regressies was redelik met r2 waardes naby 0.5 en merkwaardig hoër waardes vir area gemiddeldes. Hoë korrelasies is egter behaal vir 2 van die 3 bestudeerde landsgebruike (r2 waardes van 0.99 en 0.81 in bosbou en grasveld onderskeidelik) wanneer die gemiddelde dieptestratifikasies gebruik en gekorrigeer word vir die verandering in deeltjiedigtheid vir gronde met hoë grondorganiese material. Alhoewel die Saxton and Rawls (2006) voorspellings van bulkdigtheid gebruik kan word, behoort bulkdigtheidsbepalings egter verkieslik direk gedoen te word. Die voorgestelde modelle vir die bepaling van vertikale GOK verspreiding tot 1m gronddiepte sou die koste van grondkoolstof opnames in die studiegebied dramaties verlaag deur grondmetings tot die grondoppervlak te beperk. Grondmonsters sal in triplikaat per waarnemingspunt met 5cm diep silinders op die grondoppervlak geneem word vir ρb (bulkdigtheid) and Corg (organiese koolstof) bepalings. Die gemiddelde akkuraatheid van die genormaliseerde diepteverspreidingsmodel is hoog vir grasveld en woude/bosbou plantasies (R2 = 0.98), maar ietwat laer vir bewerkte landerye (R2 = 0.96) as gevolg van die vermenging van die ploeglaag tot op die diepte van bewerking. Koolstof voorraad tot 1m gronddiepte is bepaal deur middel van die integraal van die genormaliseerde eksponensiele verspreiding, vermenigvuldig met die waarde van Corg op die grondoppervlak en op ‘n volume basis uitgedruk as koolstofdigtheid (Cv, kg∙m-3). Die gevolglike voorraadopname is met gemete waardes vergelyk deur middel van ‘n stuksgewyse integrasie van die gemonsterde diepteinkremente om GOK voorraad per area (kg∙m-2) te lewer. Die gemiddelde geskatte fout van voorspelling was 1.2 (9%) en 3.7 kg∙m-2 (21.6%) in grasveld and plantasies onderskeidelik en 1.3 kg.m-2 (9.5%) in bewerkte landerye. Verdere verbetering van die modelle en ‘n verlaging in hierdie foute kan verkry word deur die grondtipe inligting as veranderlike in te bring en die funksies volgens grondtipe eerder as landsgebruik te groepeer. Resultate van hierdie werk is reeds aangebied tydens ‘n seminar by die department Grondkunde, Stellenbosch Universiteit (Ros Mesa et al., 2014), die gesamentlike kongres vir die Suid-Afrikaanse Verenigings vir Grondkunde, Hortologie, Onkruidwetenskap en Gewasproduksie (Rozanov et al. 2015), die Eerste Global Soil Map konferensie, Frankryk (Wiese et al, 2013), die 20ste Internasionale Grondkunde Kongres, Korea (Wiese et al. 2014) en is ingehandig vir publikasie in ‘n spesiale uitgawe van Geoderma wat, na aanleiding van die aanbieding by die 20ste Internasionale Grondkunde Kongres, Korea (Wiese et al., 2014), fokus op digitale grondkartering van grondorganiese koolstof.

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Wong, Vanessa Ngar Lai. "The effects of salinity and sodicity on soil organic carbon stocks and fluxes /." View thesis entry in Australian Digital Theses Program, 2007. http://thesis.anu.edu.au/public/adt-ANU20080428.223144/index.html.

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Wong, Vanessa, and u2514228@anu edu au. "The effects of salinity and sodicity on soil organic carbon stocks and fluxes." The Australian National University. Faculty of Science, 2007. http://thesis.anu.edu.au./public/adt-ANU20080428.223144.

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Soil is the worlds largest terrestrial carbon (C) sink, and is estimated to contain approximately 1600 Pg of carbon to a depth of one metre. The distribution of soil organic C (SOC) largely follows gradients similar to biomass accumulation, increasing with increasing precipitation and decreasing temperature. As a result, SOC levels are a function of inputs, dominated by plant litter contributions and rhizodeposition, and losses such as leaching, erosion and heterotrophic respiration. Therefore, changes in biomass inputs, or organic matter accumulation, will most likely also alter these levels in soils. Although the soil microbial biomass (SMB) only comprises 1-5% of soil organic matter (SOM), it is critical in organic matter decomposition and can provide an early indicator of SOM dynamics as a whole due to its faster turnover time, and hence, can be used to determine soil C dynamics under changing environmental conditions.¶ Approximately 932 million ha of land worldwide are degraded due to salinity and sodicity, usually coinciding with land available for agriculture, with salinity affecting 23% of arable land while saline-sodic soils affect a further 10%. Soils affected by salinity, that is, those soils high in soluble salts, are characterised by rising watertables and waterlogging of lower-lying areas in the landscape. Sodic soils are high in exchangeable sodium, and slake and disperse upon wetting to form massive hardsetting structures. Upon drying, sodic soils suffer from poor soil-water relations largely related to decreased permeability, low infiltration capacity and the formation of surface crusts. In these degraded areas, SOC levels are likely to be affected by declining vegetation health and hence, decreasing biomass inputs and concomitant lower levels of organic matter accumulation. Moreover, potential SOC losses can also be affected from dispersed aggregates due to sodicity and solubilisation of SOM due to salinity. However, few studies are available that unambiguously demonstrate the effect of increasing salinity and sodicity on C dynamics. This thesis describes a range of laboratory and field investigations on the effects of salinity and sodicity on SOC dynamics.¶ In this research, the effects of a range of salinity and sodicity levels on C dynamics were determined by subjecting a vegetated soil from Bevendale, New South Wales (NSW) to one of six treatments. A low, mid or high salinity solution (EC 0.5, 10 or 30 dS/m) combined with a low or high sodicity solution (SAR 1 or 30) in a factorial design was leached through a non-degraded soil in a controlled environment. Soil respiration and the SMB were measured over a 12-week experimental period. The greatest increases in SMB occurred in treatments of high-salinity high-sodicity, and high-salinity low-sodicity. This was attributed to solubilisation of SOM which provided additional substrate for decomposition for the microbial population. Thus, as salinity and sodicity increase in the field, soil C is likely to be rapidly lost as a result of increased mineralisation.¶ Gypsum is the most commonly-used ameliorant in the rehabilitation of sodic and saline-sodic soils affected by adverse soil environmental conditions. When soils were sampled from two sodic profiles in salt-scalded areas at Bevendale and Young, SMB levels and soil respiration rates measured in the laboratory were found to be low in the sodic soil compared to normal non-degraded soils. When the sodic soils were treated with gypsum, there was no change in the SMB and respiration rates. The low levels of SMB and respiration rates were due to low SOC levels as a result of little or no C input into the soils of these highly degraded landscapes, as the high salinity and high sodicity levels have resulted in vegetation death. However, following the addition of organic material to the scalded soils, in the form of coarsely-ground kangaroo grass, SMB levels and respiration rates increased to levels greater than those found in the non-degraded soil. The addition of gypsum (with organic material) gave no additional increases in the SMB.¶ The level of SOC stocks in salt-scalded, vegetated and revegetated profiles was also determined, so that the amount of SOC lost due to salinisation and sodication, and the increase in SOC following revegetation relative to the amount of SOC in a vegetated profile could be ascertained. Results showed up to three times less SOC in salt-scalded profiles compared to vegetated profiles under native pasture, while revegetation of formerly scalded areas with introduced pasture displayed SOC levels comparable to those under native pasture to a depth of 30 cm. However, SOC stocks can be underestimated in saline and sodic landscapes by setting the lower boundary at 30 cm due to the presence of waterlogging, which commonly occurs at a depth greater than 30 cm in saline and sodic landscapes as a result of the presence of high or perched watertables. These results indicate that successful revegetation of scalded areas has the potential to accumulate SOC stocks similar to those found prior to degradation.¶ The experimental results from this project indicate that in salt-affected landscapes, initial increases in salinity and sodicity result in rapid C mineralisation. Biomass inputs also decrease due to declining vegetation health, followed by further losses as a result of leaching and erosion. The remaining native SOM is then mineralised, until very low SOC stocks remain. However, the C sequestration potential in these degraded areas is high, particularly if rehabilitation efforts are successful in reducing salinity and sodicity. Soil ecosystem functions can then be restored if organic material is available as C stock and for decomposition in the form of either added organic material or inputs from vegetation when these salt-affected landscapes are revegetated.

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Estrela, Sílvia Regina Marques Faria. "Wildfire effects on forest soil organic matter stocks and losses by runoff." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/19151.

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Doutoramento em Ciências e Engenharia do Ambiente
O solo é considerado o maior reservatório de carbono (C) global e, um importante sumidouro de CO2 atmosférico. Os incêndios florestais são um fenómeno frequente nos ecossistemas mediterrânicos, em especial em Portugal. Nas últimas décadas verificou-se um aumento do número de incêndios e os cenários de alterações climáticas sugerem que os regimes de incêndios se poderão intensificar no futuro. Os incêndios florestais podem provocar efeitos importantes a curto e médio prazo em fatores chave da qualidade do solo, tais como a quantidade e qualidade da matéria orgânica (SOM). Devido à grande quantidade de carbono (C) armazenado no solo, mesmo pequenas mudanças na SOM poderão ter um efeito significativo sobre os ciclos biogeoquímicos e, consequentemente, sobre o clima global. Embora existam vários estudos que documentam os efeitos pós-fogo sobre os processos hidrológicos e de erosão, em termos de impactos sobre a quantidade (em termos de stocks e perdas de carbono orgânico (OC) por escorrência superficial), qualidade da SOM e sedimentos exportados, bem como a sua recuperação pós-fogo tem sido pouco estudados. Estes foram os principais objetivos deste estudo, realizado em plantações de eucalipto (Eucalyptus globulus), um dos tipos de vegetação florestal mais suscetíveis ao fogo no centro-norte de Portugal. O efeito dos incêndios florestais na qualidade da SOM do solo foi avaliado na camada superficial do solo (0-2 cm) em 4 períodos de amostragem, imediatamente antes das primeiras chuvas até dois anos após o incêndio. Para tal, foram utilizadas várias técnicas analíticas, tais como a deteção e caraterização de biomarcadores lipídicos por cromatografia gasosa/espetrometria de massa (GC-MS), caraterização de SOM por pirólise acoplada à cromatografia gasosa e à espetrometria de massa (Py-GC/MS) e, por ressonância magnética nuclear 13C de estado sólido (13C NMR). As exportações pós-fogo de OC por escorrência superficial e as respetivas contribuições das frações de carbono orgânico dissolvido (DOC), carbono orgânico particulado (POC) e carbono inorgânico dissolvido (DIC) foram também determinados em amostras de escorrência superficial recolhidas em intervalos de 1 a 2 semanas ao longo do primeiro ano após o incêndio. Os resultados mostraram que o incêndio provocou mudanças consideráveis na quantidade e qualidade da SOM. Estas incluíram a degradação térmica e quebra de compostos de n-alquilo. Aumentaram os rácios das cadeias curto-longo de n-alcanos e das cadeias de n- FAMEs, assim como a alteração dos respetivos índices. Além disso, a abundância relativa de certos biomarcadores específicos de determinadas plantas foram modificados, especialmente diminuição de terpenóides, tais como epiglobulol, ledol e globulol que são característicos do Eucalyptus globulus. Outras diferenças observadas no solo queimado foram a presença de levoglucosano, um marcador típico para a alteração térmica de polissacarídeos, maior abundância relativa de compostos derivados da lenhina (vanilina e metoxifenol) e a presença de estruturas de N-heteroaromáticos. Os espetros de 13C NMR também indicaram que o fogo produziu um aumento considerável na aromaticidade e condensação aromática da SOM. Estas diferenças verificaram-se durante o período de estudo, sugerindo uma lenta recuperação das propriedades do solo, possivelmente influenciadas, quer por uma recuperação limitada da vegetação, quer pela intensificação das perda de solo após o incêndio. O presente trabalho abordou também um tema pouco estudado como são os efeitos pós-fogo nas perdas de OC no solo por escorrência superficial. Os principais resultados apontaram para (i) uma maior quantidades de cinzas na encosta orientada a norte do que na encosta orientada a sul, enquanto que para a quantidade total de carbono orgânico (TOC) nas cinzas, estas não apresentaram diferenças; (ii) quer a perda total de sedimentos, quer a quantidade TOC do solo apresentouse maior na encosta orientada a norte do que a sul; (iii) a fração de OC que apresentou as maiores perdas, para ambas as encostas, foi a particulada. A quantificação das perdas de OC pós-fogo podem contribuir de forma relevante para a proteção dos ecossistemas, nomeadamente em termos da fertilidade do solo.
Soil is considered the largest carbon reservoir and an important global sink for atmospheric CO2. Wildfires are frequent in Mediterranean ecosystems, especially in Portugal. In recent decades there has been an increase in the number of fires and climate change scenarios suggest that the fire regimes are likely to increase in the future. Forest fires can have important short−to long−term implications for key aspects of soil quality, such as the quantity and quality of soil organic matter (SOM). Due to high amount of carbon (C) stored in soil, even slight alterations of SOM can affect significantly biogeochemical cycles, hence, affecting the whole global climate. Although numerous studies have documented the effects of wildfires on hydrological and erosion processes, the effects of fire on the quantity (in terms of stocks and losses of OC content by overland flow) and quality of SOM and in the sediments eroded, as well on postfire SOM recovery, have received considerably less research attention. These were the principal goals of the present study conducted on eucalypt plantations, one of the most fire-prone forest types in northcentral Portugal. The effects of wildfires on quality of SOM was evaluated in topsoil samples (0-2 cm) on four sampling occasions, starting immediately after the first post-fire rain till two years later. It was necessary a combination of multi-analytical techniques, such as lipid-biomarker analysis by gas chromatography-mass spectrometry (GC-MS), SOM characterization by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and solid state 13C nuclear magnetic resonance (13C NMR) spectroscopy. Post-fire OC exports by overland flow and the contributions of the dissolved organic carbon (DOC), particulate organic carbon (POC) and dissolved inorganic carbon (DIC) fractions were measured in runoff samples collected at 1- to 2- weekly intervals during the first year after the wildfire. The results showed that wildfire produced substantial changes in the quantity and quality of SOM. These included the thermal breakdown and cracking of n-alkyl compounds. Ratios of short-to-long n-alkanes and n-fatty acid methyl esters (FAMEs) increased and typical carbon number predominance indexes for n-alkanes (odd-to-even) and n-FAMEs (evento- odd) were altered. Furthermore, the relative abundances of certain markers, which are plantspecies specific were modified, especially by decreasing terpenoids such as epiglobulol, ledol and globulol, which are characteristic of Eucalyptus globulus. Other differences observed in the burnt soil were the appearance of levoglucosan, a typical marker for the thermal alteration of polysaccharides, larger relative abundances of lignin-derived compounds (vanillin and methoxyphenols) and the presence of N-heteroaromatic structures. The 13C NMR spectra also indicated that the wildfire produced a considerable increase in the aromaticity and aromatic condensation of the topsoil SOM. The continuation of these differences in SOM quality during the period of this study, suggested a slow recovery of soil properties, possibly influenced by a limited recovery of the vegetation after the fire combined with the fire-enhanced losses of soil. The present work also evaluated post-fire soil OC losses by overland flow in recently two burnt eucalypt plantations, addressing a topic that has seldom been investigated. The main findings were that: (i) the amount of deposited ashes was higher at the NW slope than at the SE slope, while ashes total organic carbon (TOC) content revealed no differences; (ii) total sediment losses and also the TOC export were higher at the NW slope than at the SE slope; (iii) particulate organic carbon fraction showed the highest loss at the both topsoil sites. In addition, this study provides some insight into post-fire organic carbon losses in the recently burnt areas, which is crucial information for ecosystem management, especially in terms of soil fertility.

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Kroll, Jeffrey T. "LANDUSE AND SOIL ORGANIC CARBON VARIABILITY IN THE OLD WOMAN CREEK WATERSHED OF NORTH CENTRAL OHIO." Miami University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=miami1165431813.

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Luther-Mosebach, Jona [Verfasser], and Annette [Akademischer Betreuer] Eschenbach. "Soil carbon stocks and dynamics in soils of the Okavango catchment / Jona Luther-Mosebach ; Betreuer: Annette Eschenbach." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2018. http://d-nb.info/1151076511/34.

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Zani, Caio Fernandes. "Evaluation of soil carbon stocks in response to management changes in sugarcane production." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-24082015-143738/.

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Brazilian commodities, such as ethanol, are looking for sustainable production to suit the international market demands. An important parameter for assessing sustainability is the carbon (C) footprint calculation of the product. Thus, studies of the variations in soil C stocks on the ethanol production are essential. Studies in relation to land use change are already been developed; however information about parameters of management changes on the sugarcane production is needed. The aim of this research was to evaluate the soil C stock in response to two main management changes in sugarcane production: i) no vinasse to vinasse application (NV-V), ii) burned to unburned harvesting system (B-UB). We also evaluated soil C stock changes in a chronosequence irrigation practices (native vegetation (NV), sugarcane irrigated 4 years (I4) and 6 years (I6), a new management in semi-arid and drought regions in Brazil which also aims high yields. Modelling approaches in order to assess long-term effects were also analysed. The NV-V transition showed higher soil C stock for V regime for topsoil layers 0-40 cm depth mainly due to the addition of organic compounds to the soil. Vinasse can also enhance biomass production and crop yield. The B-UB transition showed higher soil C stock in the UB regime from 20 to 60 cm depth due to higher organic matter accumulation from the maintenance of the straw to the field. The cumulative soil C stock for 1 metre depth had an increase of 1.1 and 0.75 Mg C ha-1 y-1 in the NV-V and B-UB transitions, respectively. From modelling was observed that V and UB sites had an increase of soil C stock by 2150, being a difference of 2.8 and 23 Mg ha-1 in the equilibrium state between NV-V and B-UB regimes, respectively. In the irrigation practices, the I4 showed higher soil C stock than NV in the 20 to 40 cm; while I6 was lower than NV in the 50 to 100 cm depth. Simulated long-term analyses showed increase of topsoil C stock of 12 and 13 Mg ha-1 for I6 and I4 area, respectively, compared to NV on 2100. The results in this study are pioneers in relation to soil C stock studies in the management transitions and irrigation practices. This information may be used as a basis for public policies decision which dealing of the land use and global warming
Commodities brasileiras, como o etanol, estão à procura de uma produção sustentável para atender às exigências do mercado internacional. Um parâmetro importante para avaliar a sustentabilidade é o cálculo da pegada de carbono (C) do produto. Assim, os estudos sobre as variações nos estoques de carbono do solo (ECS) sobre a produção de etanol são essenciais. Estudos em relação à mudança no uso da terra já estão sendo desenvolvidos; no entanto informações sobre parâmetros de mudanças de manejo na produção de cana de açúcar são necessárias. O objetivo desta pesquisa foi avaliar o ECS em resposta a duas principais mudanças de manejo: i) não vinhaça para aplicação de vinhaça (NV-V), ii) sistema queimado para não queimado (B-UB). Mudanças de ECS também foram avaliadas em sistemas de irrigação em cronoseqüência: vegetação nativa (NV), cana de açúcar irrigada por 4 anos (I4) e por 6 anos (I6). Modelagem matemática para avaliar o efeito a longo prazo também foi analisada. A transição NV-V apresentou maior ECS para o regime V em 40 cm de profundidade, devido principalmente à adição de compostos orgânicos ao solo. A vinhaça também pode aumentar a produção de biomassa e rendimento da cultura. A transição B-UB apresentou maior ECS no regime UB em 20-60 cm de profundidade devido ao acúmulo de matéria orgânica a partir da manutenção da palha no campo. O ECS acumulado para 1 metro de profundidade obteve um aumento de 1,1 e 0,75 Mg C ha-1 y-1 nas transições NV-V e B-UB, respectivamente. A partir de modelagem foi observado que os regimes V e UB obteve um aumento de ECS em 2150, sendo uma diferença de 2,8 e 23 Mg ha-1 no estado de equilíbrio para os regimes NV-V e B-UB, respectivamente. Nas práticas de irrigação, o I4 foi superior ao NV nos 20 a 40 cm; enquanto que I6 foi inferior a NV na profundidade de 50 a 100 cm. As análises de simulação a longo prazo mostraram um aumento de ECS de 12 e 13 Mg ha-1 para as áreas I6 e I4, respectivamente, em comparação com NV em 2100. Os resultados deste estudo são pioneiros em relação aos estudos de ECS nas mudanças de manejo e práticas de irrigação. Esta informação pode ser usada como base para a decisão de políticas públicas que lidam com o uso da terra e do aquecimento global

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McClean, Gary James. "Impact of land-use change for lignocellulosic biomass crop production on soil organic carbon stocks in Britain." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/19568.

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The contribution of energy from biomass sources is projected to increase in Britain to assist in meeting renewable energy targets and reducing anthropogenic CO2 emissions. With increasing concerns over the sustainability of food crop-based biofuels, purpose-grown lignocellulosic biomass crops such as Miscanthus and short rotation coppice (SRC) willow have been promoted as more sustainable feedstocks for the production of heat and electricity as well as for the future production of liquid biofuels. With the introduction of the Energy Crops Scheme, land-use change (LUC) for lignocellulosic biomass crop production has become increasingly common in Britain in recent decades. However, there is limited understanding of the impact this has on soil organic carbon (SOC) stocks and limited predictability concerning the overall trajectory, magnitude and rate of SOC changes under a range of different conditions. Using a chronosequence of 93 biomass crop plantations in England and Wales, mainly of 1 to 14 years age, empirical models were developed to determine the short term trajectory of SOC stocks following LUC from arable and grassland to SRC willow and Miscanthus production. SOC stocks were calculated for each site using a fixed sampling depth of 30 cm and estimated changes were inferred by comparing with typical pre-change SOC stocks. These results indicate that only LUC from arable crops to SRC willow demonstrated an overall increase in SOC stocks, by an estimated 15.3 ± 2.2 t C ha-1 (± 95% confidence intervals) after 14 years and 68.8 ± 49.4 t C ha-1 after 22 years. LUC from arable crops to Miscanthus and from both arable crops and grassland to SRC willow and Miscanthus demonstrated no overall net effect on SOC stocks. Soil texture and climate data were measured for each site and multivariable models were created to assess the influence of different environmental conditions on SOC trajectory. In most cases the addition of these explanatory variables improved the model fit, and the models provide some preliminary estimates of more region-specific changes in SOC following LUC. Since LUC to biomass crops often causes a loss of SOC, at least in the short term, the potential for pyrogenic carbon (PyC) to ameliorate this effect was investigated. Studies indicate that PyC can interact with and stabilise native SOC, a process termed negative priming, although the potential for PyC to reduce LUC-induced losses of SOC by negative priming has not yet been assessed. Although negative priming has been observed in many studies, most of these are long term incubation experiments which do not account for the impact of environmental weathering of PyC on interactions with native SOC. Here the aim was to assess the impact of environmentally weathered PyC on native SOC mineralisation at different points in LUC from arable crops to SRC willow. Soil was sampled to a 5 cm depth from multiple recently established SRC willow plantations approximately 2 years after amendment with PyC. Cumulative CO2 flux was measured weekly from incubated soil and soil-surface CO2 flux was also measured in the field. The results demonstrate a PyC-induced increase in CO2 flux for the surface 5 cm of soil. However, no net effect on soil-surface CO2 flux was observed in the field. Although the mechanisms for these contrasting effects remain unclear, they do not suggest that PyC can reduce LUC-induced SOC losses through negative priming.

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Silva, Moreira Cindy. "Stocks de carbone du sol dans les zones de reboisement : bases pour projets de mécanisme pour un développement propre." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20228/document.

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Malgré l'importance de la séquestration du carbone (C) dans les sols forestiers, il existe actuellement peu de projets Mécanisme pour un Développement Propore (MDP) qui tiennent compte de la gestion de ce compartiment dans l'atténuation du réchauffement climatique. La cause principale est que l'accréditation du carbone séquestré dans le sol représente de plus grands défis et des risques par rapport aux autres composantes des écosystèmes forestiers.Connaissant les difficultés économiques et les problèmes environnementaux impliqués dans l'adoption d'un tel projet et l'importance des forêts dans l'atténuation du changement climatique, l'objectif de cette étude était d'évaluer les performances des méthodes dedétermination des stocks de carbone du sol dans deux projets de reboisement, ainsi que pour leurs situations de références (c'est-à-dire utilisation des terres avant la plantation, des pâturages naturels, ainsi que la végétation native) comme base pour diminuer le rapport coût bénéfice des projets MDP dans le secteur forestier. Pour atteindre l'objectif principal, cestravaux de recherches ont consisté à l'étude de: (i) la variabilité spatiale du C du sol dans une zone de reboisement avec des espèces indigènes, établi dans le bassin amazonien dans le MatoGrosso à Cotriguaçu (Zone I) et une chronoséquence de plantations d'Eucalyptus, située dansl'état de São Paulo à Avare (zone II); (ii) la taille des parcelles et la distance idéale de séparation des échantillons à partir de l'étude de la dépendance spatiale du C, (iii)l'estimation de la teneur en C et la densité du sol (Ds) par spectroscopie dans le proche(NIRS) et moyen (MIRS) infrarouge, afin de réduire les coûts sans affecter la qualité des résultats analytiques : et (iv) du calcul des stocks de C du sol pour ces deux projets et l'estimation du bilan C du projet MDP menées dans la zone II, en utilisant l'outil EX-ACT («EX-Ante Carbon-balance Tool»). Les résultats ont confirmé l'existence d'une variabilité spatiale importante du C du sol, ainsi qu'une forte dépendance spatiale pour tous les traitements étudiés. L'analyse du nombre optimal d'échantillons de sol a montré que la collecte de cinq points par parcelle est aussi précise qu'un échantillonnage plus dense. La taille optimale des parcelles a été estimée de 361 à 841 m2 dans les plantations de la zone I et de 900 à 3721 m2 pour la Zone II. La performance de la spectroscopie MIRS et NIRS pourestimer la teneur en C des sols a été jugée très satisfaisante, surtout quand les modèles ont été étalonnés à partir de sous populations constituées de 10 à 50% de l'ensemble des données.Les résultats de l'estimation de Ds ont été légèrement moins satisfaisants que ceux pour le Cdu sol. Les stocks de C dans le sol calculés pour la zone I étaient supérieurs à ceux de la zone II. Si on ne considère que le compartiment du sol, il apparaît que le potentiel de génération de crédits C est plus important dans le reboisement à partir d'espèces indigènes dans un sol argileux que pour un reboisement d'eucalyptus dans un sol sableux. Le bilan C du projet de la zone I a montré un potentiel de séquestration de près de trois millions de tonnes d'équivalentCO2 en 40 ans. Il est espéré que cette étude qui montre des possibilités de réduction des coûts liés aux calculs des stocks de C du sol contribuera à une meilleure prise en compte de ce compartiment dans les projets MDP forestiers
Considering the great importance of carbon sequestration (C) in forest soils, there are fewCDM projects that include this compartment as an agent of global warming mitigation. Thisoccurs because the quantification of soil C stocks represents a bigger challenge whencompared to other components of forest ecosystems. Considering the economic difficultiesand environmental issues involved in adopting this type of project and the importance offorests in mitigating climate change, the objective of this study was to evaluate theperformance of methods for obtaining soil C stocks in two forestry areas and their respectivebaselines (land use prior to planting, i.e. pastures and native vegetation) as a basis forreducing the cost-benefit ratio of CDM projects. To achieve the main objective, this researchwas composed of the following steps: (i) estimating the spatial variability of soil C in an areareforested with native species, established in Cotriguaçú, MT (Area I) and a Eucalyptuschronosequence, located in Avaré, SP (Area II), (ii) determining the optimal amount of soilsamples and the plot size from the soil C spatial dependence range in the reforestation areas,(iii) estimating soil C content and bulk density (BD) by Near and Mid Infrared ReflectanceSpectroscopy (NIRS and MIRS, respectively) to reduce analytical costs without affecting thequality of the results, and (iv) calculating soil C stocks in both areas and estimating the carbonbalance of a CDM Project conducted in Area II, using EX-ACT ("Ex-Ante Carbon BalanceTool"). The results confirmed the existence of significant soil C spatial variability in bothareas and a strong spatial dependence at all plots. The analysis of the optimal number of soilsamples indicated that the sampling procedure with five points per plot is as accurate asintensive sampling. The optimum size of plots ranged from 361-841 m2 at Area I plantationsand from 900-3721 m2 at Area II. The performance of MIRS and NIRS to estimate the soilcarbon content was very satisfactory, especially when the models were calibrated withamounts between 5-10% of the total data set. The estimations of BD were slightly less precisethan those of soil C content. The soil C stocks obtained at Area I were higher than Area II.Considering only the soil compartment, it is clear that the potential for C credit generation in areforestation with native species on a clayey soil is higher than in a reforestation witheucalyptus on a sandy soil. The C balance of the CDM project conducted in Area I is expectedto sequester almost three million tones of CO2 eq in 40 years. We hope this study contributesto the increased inclusion of soil in CDM projects, by confirming the feasibility of reducingthe costs associated with both sampling and analytical procedures

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Quibel, Edouard. "Impacts de la préparation du sol lors de la phase de plantation sur la dynamique des matières organiques et la fonction de stockage du Carbone dans les sols forestiers Impact du travail du sol localisé sur le stock de carbone organique du sol et la communauté microbienne en condition de plantation en forêt tempérée Changes in soil organic carbon stock by mechanical site preparation in oak and pine plantations on an acidic soil Impact du travail du sol localisé sur le stock de carbone organique du sol et la communauté microbienne en condition de plantation sur sol à engorgement temporaire en eau." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR017.

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Dans le contexte actuel de changement climatique, la forêt est vue comme un puits de carbone, c’est-à-dire qu’elle contribue à stocker du C. Ce stockage peut s’effectuer à moyen terme dans la biomasse ligneuse et à plus long terme dans les sols. Afin de préserver les forêts et leur capacité de stockage, les gestionnaires forestiers se voient contraints d’effectuer de la régénération artificielle, c’est-à-dire de la plantation pour adapter les peuplements aux conditions futures. Pour assurer le succès de cette étape de plantation, il est parfois nécessaire de lever certaines contraintes comme la présence de végétation bloquante, de tassement ou d’engorgement en eau des sols. Pour ce faire, une Préparation Mécanique des Sols (PMS) peut être effectuée avant la plantation. Ces travaux de PMS sont susceptibles de provoquer une perte de Carbone Organique du Sol (COS). Afin de limiter les effets négatifs de la PMS, des outils ont été développés afin de ne préparer le sol que de manière localisée, sur la future ligne de plants. Ces outils ont été développés pour répondre à certaines situations. Les outils Scarificateur Réfersible® et le sous-soleur multifonction® (MFSS) sont faits pour préparer des sols tassés et/ou envahis par la fougère aigle (Pteridium aquilinum). Les outils Razherb® (RAZ) et Culti 3B® (C3B) sont, quant à eux, utilisés pour préparer des sols tassés et/ou engorgés en eau envahis par la molinie (Molinia caerulea). Dans un premier temps, appuyé sur 6 sites du réseau ALTER, l’impact de l’outil RS, seul ou en combinaison avec MFSS, sur le COS a été évalué 5 ans après la PMS. Leur impact a été évalué sur le COS de manière quantitative et qualitative mais également sur le fonctionnement microbien du sol. Cette étude a montré, sur la zone travaillée, une baisse du stock de C sur le profil de sol complet (L-60 cm) et du C minéralisé par la communauté microbienne en conditions contrôlées. Cependant, il a également été démontré que les caractéristiques du sol modulent l’impact de ces outils à l’échelle de la parcelle forestière. Dans un deuxième temps, appuyé sur 3 sites du réseau PILOTE, l’impact de la combinaison d’outils RAZ+C3B a été évalué sur les stocks de COS et sur la minéralisation potentielle. Sur ces sols à engorgement temporaire, une baisse de stock de COS a été observée dans la zone travaillée uniquement dans le topsoil (L-30 cm). En revanche, le stock de COS sur le profil complet comme la minéralisation potentielle ne présentaient pas d’effet significatif sur la zone travaillée. A l’échelle de la parcelle forestière, la combinaison RAZ+C3B n’a pas présenté d’effet sur les stocks de COS ni sur la minéralisation potentielle. Dans son ensemble, ce travail de thèse suggère que bien qu’ayant un impact sur la zone préparée, les outils utilisés dans cette étude n’influençaient que peu le sol à l’échelle de la parcelle forestière. Toutefois, ces observations peuvent varier selon le type de sol en présence et avoir un impact important
In the current context of climate change, forests are seen as a carbon sinj, i. e. they can contribute to C storage. This storage can take place in the medium term in woody biomass and in the longer term in soils. In order to preserve forests and their C storage capacity, foresters have to carry out artificial regeneration (i. e. planting) to adapt stands to future conditions. To ensure the success of this planting stage, it is sometimes necessary to remove some constraints such as the presence of blocking vegetation, compaction or waterlogging of soil. To do this, a Mechanical Soil Preparation (MSP) can be carried out prior to plantin. This PMS work may cause a Soil Organic Carbon (SOC) loss by mineralization. In order to limit the negative effects of PMS, tools have been developed to prepare the soil only in a localized area, on the future line of plants. These tools have been developed to respond to some situations. The Reversible Scarifier® (RS) tool and the Multifunction Subsoiler (MFSS) are designed to prepare soils compacted and/or invaded by eagle fern (Pteridium aquilinum). The Razherb® (RAZ) and the Culti 3B® (C3B) tools are designed to prepare compacted and/or waterlogged soils invaded by Molinia caerulea (Molinia caerulea). First, based on 6 sites belonging to the ALTER network, the impact of the RS tool alone and in combination with MFSS on COS was evaluated 5 years after the PMS. This evaluation therefore focused on the quantity and quality of SOC. The impact of the tools on the microbial functioning of the soil was also tested. This part showed a decrease in the stock of C and mineralized C by the microbial community under controlled conditions localized to the prepared area but impacts at the forest stand scale depend on soil characteristics. Second, based on 3 sites belonging to the PILOTE network, the impact of the combination of RAZ+C3B tools on SOC stocks and potential mineralization was evaluated. On these soils with temporary waterlogging, adecrease in SOC stock was observed in the prepared area only in the topsoil (0-30 cm). On the other hand, both SOC stock on the full profile and the potential mineralization did not have a significant effect on the prepared area. At the forest stand scale, the RAZ+C3B combination had no effect on SOC stock or potential mineralization. This thesis work suggests that although they had an impact on the prepared area, the tools used in this study had low influence on the soil at the forest plot scale. However, these observations may vary according to the soil type and have a significant impact on the forest plot

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Taalab, Khaled Paul. "Modelling soil bulk density using data-mining and expert knowledge." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8273.

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Data about the spatial variation of soil attributes is required to address a great number of environmental issues, such as improving water quality, flood mitigation, and determining the effects of the terrestrial carbon cycle. The need for a continuum of soils data is problematic, as it is only possible to observe soil attributes at a limited number of locations, beyond which, prediction is required. There is, however, disparity between the way in which much of the existing information about soil is recorded and the format in which the data is required. There are two primary methods of representing the variation in soil properties, as a set of distinct classes or as a continuum. The former is how the variation in soils has been recorded historically by the soil survey, whereas the latter is how soils data is typically required. One solution to this issue is to use a soil-landscape modelling approach which relates the soil to the wider landscape (including topography, land-use, geology and climatic conditions) using a statistical model. In this study, the soil-landscape modelling approach has been applied to the prediction of soil bulk density (Db). The original contribution to knowledge of the study is demonstrating that producing a continuous surface of Db using a soil-landscape modelling approach is that a viable alternative to the ‘classification’ approach which is most frequently used. The benefit of this method is shown in relation to the prediction of soil carbon stocks, which can be predicted more accurately and with less uncertainty. The second part of this study concerns the inclusion of expert knowledge within the soil-landscape modelling approach. The statistical modelling approaches used to predict Db are data driven, hence it is difficult to interpret the processes which the model represents. In this study, expert knowledge is used to predict Db within a Bayesian network modelling framework, which structures knowledge in terms of probability. This approach creates models which can be more easily interpreted and consequently facilitate knowledge discovery, it also provides a method for expert knowledge to be used as a proxy for empirical data. The contribution to knowledge of this section of the study is twofold, firstly, that Bayesian networks can be used as tools for data-mining to predict a continuous soil attribute such as Db and that in lieu of data, expert knowledge can be used to accurately predict landscape-scale trends in the variation of Db using a Bayesian modelling approach.

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Ferreira, Ademir de Oliveira. "COMPARTIMENTOS DA MATÉRIA ORGÂNICA DO SOLO COMO INDICADORES DO SEQÜESTRO DE CARBONO EM SISTEMA PLANTIO DIRETO DE LONGA DURAÇÃO." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2009. http://tede2.uepg.br/jspui/handle/prefix/2199.

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Made available in DSpace on 2017-07-25T19:29:43Z (GMT). No. of bitstreams: 1 Ademir Oliveira Ferreira.pdf: 1294842 bytes, checksum: 8d7036f6aefa0cf3c549b0c63029e109 (MD5) Previous issue date: 2009-07-13
Decrease in soil organic carbon (SOC) content of the surface layer into deeper layers indicates the occurrence of the stratification in the profile due to continuous C addition of crop residues enriching the soil surface layer. The objective of this study was: in Chapter 3 the relationship of stratification (RE) of C of the soil organic matter (SOM) pools can be an indicator of C sequestration in no-tillage soils? In the chapter 4 the tensile strength of aggregates is affected by the C content of Pedosequence of Latosol with medium and clay texture? in Chapter 5 which is the C balance and the amount of crop residue needed to maintain a stable C balance in a Latosol with a medium and clay texture? The experimental design was a completely randomized 2x2x2 factorial with 12 treatments. Treatments consisted of: a) an Oxisol (Red Latosol) with medium and clayey texture, b) two soil sampling periods (T1 and T2) with one year interval between them, and c) two soil sampling depths (0-5 and 5-20 cm). The soil attributes assessed were: the separation of water stable aggregates classes (19-8, 8-4, 4-2, 2-1, 1-0,5 and 05-0,25 mm), particulate organic carbon (POC), total particulate nitrogen (TPN) in the aggregate classes. Also was determined total organic carbon (TOC) and total nitrogen (NT) in the whole sample and in the aggregates sizes classes and tensile strength of aggregates. The relationship of stratification was calculated by dividing the TOC and TN values of 0-5 cm layer by the values of the same attributes of 5-20 cm layer. The C sequestration rate and the stratification ratio changes were calculated by the difference between the T2 values minus T1. The tensile strength was measured in soil aggregates and assessed in 1920 aggregates for each sampling time. Also TOC and NT content were measured in aggregates. The aggregates greater than 8 mm represented more than 70 of the total mass in both the clay and in sandy soil. The relationship of stratification ratio (0-5:5-20 cm) of SOC, TN, POC and TPN soil indicated the improvement of the surface layer. A significant linear relationship between the SR and C sequestration rate in both textural classes showed an increase in C sequestration and was more evident in LV with medium texture. The increase in TOC content resulted in decreased tensile strength (TS) of the aggregates and was more evident in the 0-5 cm layer. The TS showed inverse relationship with the soil density and was higher in the LV medium texture. The rate of sequestration of C was 0.86 for the LV with medium texture and 0.76 Mg ha-1 for the clay texture and to maintain the stable balance of C is required an input of 8.6 Mg ha-1 of crop residues. The results presented confirm the hypothesis of SR to be a sensitive indicator for the rate of carbon sequestration in no-tillage soil. Key-words: Carbon stock, Carbon balance, Carbon sequestration, Soil management systems, particulate organic carbon, particulate nitrogen.
A redução no conteúdo de carbono (C) da camada superficial em direção as camadas mais profundas do solo indica a formação da estratificação no perfil devido à adição contínua de C pelos resíduos orgânicos resultando no enriquecendo a camada superficial do solo. O objetivo deste trabalho foi avaliar os seguintes assuntos: a) a relação de estratificação (RE) de C dos compartimentos da matéria orgânica do solo (MOS) pode ser um indicador do seqüestro de C no sistema plantio direto. b) a resistência tênsil dos gregados pode ser afetada pelo conteúdo de C em Pedossequencia de Latossolo com textura média e argilosa. c) o balanço de C e a quantidade de resíduos culturais necessária para manter o equilíbrio estável de C em um Latossolo com textura média e argilosa. O delineamento experimental foi um fatorial 2x2x2 inteiramente casualizado com 12 tratamentos. Os tratamentos constituíram-se de: a) um Latossolo Vermelho com textura média e argilosa, duas épocas de amostragem do solo (E1 e E2) com um ano de intervalo entre si e duas profundidades de amostragem (0-5 e 5-20 cm). Os atributos avaliados foram: a separação das classes de agregados do tamisamento úmido (19-8, 8-4, 4-2, 2-1, 1-0,5 e 05-0,25 mm), o carbono orgânico particulado (COP), o nitrogênio total particulado (NTP) nas classes de agregado, o C orgânico total (COT) e o nitrogênio total (NT) na amostra integral e nas classes de agregados e a resistência tênsil dos agregados. A relação de estratificação (RE) foi calculada dividindo-se o valor de COT e NT da camada de 0-5 cm pelo valor na camada 5-20 cm. A taxa de seqüestro de C e a variação da relação de estratificação foram calculadas através da diferença (D) entre os valores da E2 menos o da E1. A resistência tênsil (RT) do solo foi avaliada em 1920 agregados de cada época de coleta, determinando-se, também o conteúdo de COT e NT. A classe de agregado > 8 mm representou mais de 70% da massa dos agregados tanto na textura argilosa como na arenosa. Da mesma forma, o conteúdo de COT e NT foram maiores na classe de agregado > do que 4 mm comparado as demais classes nas duas classes texturais. A relação de estratificação 5:5-20 cm) de COT, NT, COP e NTP do solo indicou a melhoria da qualidade do solo da camada superficial. A relação linear e significativa entre o DRE com a taxa de seqüestro de carbono nas duas classes texturais mostrou o aumento no seqüestro de C e foi mais evidente no LV com textura média. O incremento do conteúdo de COT resultou na diminuição da resistência tênsil (RT) dos agregados e foi mais evidente na camada de 0-5 cm. A RT apresentou relação inversa com a densidade do solo e foi superior no LV textura média. A taxa de seqüestro de C foi de 0,86 para o LV textura média e 0,76 Mg ha-1 para o textura argilosa e para manter o equilíbrio estável de C é necessário o aporte de 8,6 Mg ha-1 de resíduos culturais. Os resultados apresentados confirmaram a hipótese da RE ser um indicador sensível para a taxa de seqüestro de carbono no solo em um sistema sob plantio direto consolidado.

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Carrasco, Barea Lorena. "Soil and vegetation carbon dynamics (stocks and fluxes) and litter decomposition in a Mediterranean non-tidal salt marsh." Doctoral thesis, Universitat de Girona, 2020. http://hdl.handle.net/10803/670976.

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Salt marshes are considered key ecosystems for climate regulation because they have a high carbon sequestration capacity. However, most studies of carbon sequestration capacity of these ecosystems have been performed in tidal salt marshes, mainly in North America, being studies from non-tidal salt marshes, such as those of the Mediterranean Basin, really scarce. In this thesis it has been analyzed the amount of carbon stored in vegetation and soil, the fluxes of carbon dioxide in vegetation and the fluxes of carbon dioxide and methane in soil, as well as the litter decomposition of the dominant plant species in a non-tidal Mediterranean salt marsh. Results from this thesis contribute to increase the knowledge on carbon dynamics and litter decomposition in Mediterranean Basin salt marshes.
Las marismas halófilas se consideran ecosistemas clave en la regulación climatica ya que presentan una alta capacidad de secuestro de carbono. Sin embargo, la mayoría de estudios sobre la capacidad de secuestro de carbono de estos ecosistemas se han realizado en marismas halófilas mareales, principalmente de Norte América, siendo escasos los estudios realizados en marismas no marelaes, como las de la cuenca de Mediterráneo. En esta tesis se ha analizado la cantidad de carbono almacenado en vegetación y suelo, los flujos de dióxido de carbono en vegetación y de dióxido de carbono y metano en suelo, así como la descomposición de la hojarasca de las especies vegetales dominantes en una marisma Mediterránea no mareal. Los resultados de esta tesis contribuyen a incrementar el conocimiento sobre la dinámica del carbono y la descomposición de la hojarasca en las marismas halófilas de la cuenca del Mediterráneo.

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Arai, Hirotsugu. "Factors and mechanisms that change soil organic carbon stocks and dynamics after afforestation in a Japanese coniferous plantation." Kyoto University, 2011. http://hdl.handle.net/2433/142337.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第16139号
農博第1875号
新制||農||991(附属図書館)
学位論文||H23||N4609(農学部図書室)
28718
京都大学大学院農学研究科森林科学専攻
(主査)教授柴田昌三, 教授大澤晃, 教授吉岡崇仁
学位規則第4条第1項該当

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20

Ngo, Thi Phuong. "Effets des amendements organiques exogènes sur la composition de la matière organique et le stockage du carbone d'un sol dégradé par l'érosion dans le Nord du Vietnam." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066152/document.

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Une stratégie pour améliorer durablement la fertilité des sols dégradés par érosion au Nord du Vietnam consiste à apporter des amendements organiques exogènes (AOEs). L'application du lisier de buffle, son compost et lombricompost, ainsi que le biochar permettraient à faible coût d’améliorer la qualité des sols et la croissance des plantes en réduisant l'utilisation d'engrais, mais également de séquestrer du carbone. L’objective de cette thèse est d’évaluer (1) l’utilité des quatre AOEs seuls ou en association pour séquestrer du carbone, et (2) l’effet de l’apport des quatre substrats organiques seuls ou en association sur la quantité et qualité des matières organiques d’un sol agricole tropical dégradé typique du Nord du Vietnam. Pour répondre à cet objectif, nous avons effectué des incubations au laboratoire, en sachet de litière dans des conditions de terrain et suivi pendant trois ans une expérience en mesocosme avec ajouts des AOEs au sol cultivé en conditions de terrain.Nos résultats montrent que le compostage en présence de vers de terre conduit à une plus forte transformation de la matière organique issue du lisier de buffle par rapport au compostage traditionel. Le lombricompost était enrichi en composés azotés et appauvri en polysaccharides, et se caractérisait par une altération plus importante des lignines en comparaison avec le compost. La stabilité biologique de ces AOEs a été liée à leur teneur en carbone soluble, diminuant suivant l’ordre : lisier de buffle > compost > lombricompost, alors que leur réactivité chimique était similaire. Le biochar, constitué de carbone aromatique, se caractérisait par une très forte stabilité biologique et chimique. L’association du biochar avec les autres AOEs a influencé leur stabilité chimique et biologique, en protégeant la matière organique labile contre l'oxydation chimique et la dégradation biologique.Notre expérience de trois ans en mésocosmes en conditions naturelles a montré que tous les AOEs ont un effet positif sur le stockage du carbone dans le sol ainsi que sur la qualité de la matière organique de sol. L’association de biochar et de lombricompost en augmenttant l’abondance des composés dérivés de la lignine ainsi que la teneur en sucre provenant des plantes et des microorganismes, semble montrer un effet synergique de cette association sur la fertilité des sols (activité microbienne, prospection racinaire). Comparé aux résultats d’incubation en sachet de litières, ces résultats indiquent un effet significatif et contrasté des AOEs sur la croissance des plantes en particulier sur l’apport racinaire. En conclusion, l’association de biochar et de lombricompost semble la meilleure solution pour améliorer la qualité de sol dégradé par l'érosion dans le Nord du Vietnam. Ces résultats devront être confirmés par des études à long terme, tant du point de vue de la qualité physicochimique que biologique des sols amendés par ces AOEs
Intensification of agricultural use of tropical soils in Northern Vietnam leads to acidification associated with organic matter loss, rapid decline of their fertility and high erosion rates. Such negative effects may be counteracted by exogenous organic amendments (EOMs). The application of buffalo manure, its compost and vermicompost and biochar alone or in mixture with other EOMs is promising to improve at low cost soil quality, plant growth and carbon sequestration. The aims of this study were to evaluate (1) the usefulness of the four EOM alone or in mixture to sequester carbon and (2) the effect of these amendments on quantity and quality of soil organic matter of a tropical soil degraded by erosion. To anwer to this objective we carried out incubations in the laboratory, in litterbags under field conditions and we monitored a mesocom experiment, where the EOM were added and subjected during three years to cultivation and natural rainfall conditions. Our results showed that composting in the presence of earthworms led to stronger transformation of buffalo manure than regular composting. Vermicompost was enriched in N-containing compounds and depleted in polysaccharides. It further contained stronger modified lignin compared to regular compost. Biological reactivity of these AOEs was related to their soluble organic matter content, which decreased in the order buffalo manure > compost > vermicompost, whereas their chemical reactivity was similar. Bamboo biochar was enriched in aromatic carbon and characterized by a high biological and chemical recalcitrance. The presence of biochar influenced the biological as well as chemical reactivity of the other organic amendments. It led to a protection of organic matter against chemical oxidation and changed their susceptibility to biological degradation. Our experience with mesocosmes during 3 year under the natural conditions showed that all organic amendments had a positive effect on soil carbon storage and significantly influences soil organic matter quality. Biochar could increase the soil carbon sequestration potential, when applied in mixture with vermicompost. The presence of biochar increased lignin derived compounds abundance as well as both plant and microbial sugar content of soil amended with vermicompost but it had no effect in the case of control soil. Compared to our litterbag experiment these results show that EOM have a strong contrasting effect on plant growth, in particular root litter input. In conclusion, the incorporation of biochar and vermicompost seems to be the best solution to improuve the quality of degraded soil in Northem Vietnam. More studies about the impacts of this amendment on soil physico-chemical and biological properties in long-term are needed to comfirm these results

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Dang, Thi Thu Huong, and Huu Thu Do. "Biomass and carbon stocks of the natural forests at Me Linh biodiversity station, Vinh Phuc province, Vietnam." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-190821.

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Biomass and carbon stock of the natural forests in Vietnam are still not clear due to limitation of knowledge and financial. In this paper, the results of estimating biomass and carbon stocks of the natural forests at Me Linh Biodiversity Station are shown. There are two forest types in this study: the forest vegetation restored after shifting cultivation (vegetation type I) and the forest vegetation restored after clear cutting exploitation (vegetation type II). As the results, the estimated biomass of the forest vegetation restored after shifting cultivation is 86.80 ton.ha-1 and the estimated biomass of the forest vegetation restored after clear cutting exploitation is higher, about 131.59 ton.ha-1. The carbon stock in plants was about 43.40 ton.ha-1 of vegetation type I and 65.79 ton.ha-1 of vegetation type II. The carbon storage in soil of vegetation type I is 79.01 ton.ha-1 and vegetation type II is 99.65 ton.ha-1. Hence, the total of carbon stock in forest vegetation I and II are accounted by 122.41ton.ha-1 and 165.44 ton.ha-1, respectively. In general, it can be pointed out that the naturally recovering secondary forest at Me Linh Station is the secondary young forest with the low economic value due to shortly restored process (about 10-20 years), the flora is not rich and abundant, and there are only commonly pioneer and light demanding tree species
Sinh khối và trữ lượng các bon của rừng tự nhiên ở Việt Nam vẫn ít được quan tâm của do hạn chế về kiến thức và tài chính. Trong bài báo này, chúng tôi đưa ra kết quả của việc ước lượng sinh khối và tổng hợp các bon của các thảm thực vật rừng thứ sinh phục hồi tự nhiên tại Trạm Đa dạng Sinh học Mê Linh, tỉnh Vĩnh Phúc- Việt Nam, nơi có loại hình thảm thực vật chính, đó là thảm thực vật phục hồi sau nương rẫy (kiểu thảm thục vật I) và thảm thực vật phục hồi sau khai thác kiệt (kiểu thảm thực vật II) nhằm mục đích đánh giá tiềm năng của rừng thứ sinh tại khu vực nghiên cứu. Sinh khối của thảm thực vật phục hồi sau nương rẫy là 86,80 tấn/ha. Sinh khối của thảm thực vật phục hồi sau khai thác cao hơn, đạt 131.59 tấn/ha. Lượng các bon hấp thu trong đất của thảm thực vật I là 79,01 tấn/ha và thảm thực vật II là 99,65 tấn/ha. Như vậy, tổng lượng các bon được hấp thu trong mỗi loại hình thảm thực vật trên là: 122,41 tấn/ha (thảm thực vật I) và 165,14 tấn/ha. Nhìn chung, rừng thứ sinh phục hồi tự nhiên tại Trạm Đa dạng Mê Linh chủ yếu là rừng non thứ sinh, ít có giá trị kinh tế do quá trình phục hồi diễn ra ngắn (khoảng 10-20 năm) nên thành phần thực vật nghèo nàn, không phong phú, thành phần chính chủ yếu là các cây gỗ tiên phong, ưa sáng

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22

Venkatapen, Corinne. "Étude des déterminants géographiques et spatialisation des stocks de carbone des sols de la Martinique." Thesis, Antilles-Guyane, 2012. http://www.theses.fr/2012AGUY0513/document.

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Les stocks des éléments dans les sols, et en particulier ceux du carbone, sont en constante évolution sous l’effet de facteurs naturels (climat, végétation, teneurs en argiles, etc.) et anthropiques (usages des sols, etc.). Notre objectif est donc, (i) de mieux comprendre les relations entre type de sol, système de culture et quantité de carbone stockée, (ii) d’étudier les conséquences des changements d’usage et de gestion des terres sur les formes de matière organique dans les sols et (iii) de préciser le rôle de la matière organique sur les propriétés physiques des sols.Des situations agro-pédologiques représentatives des trois grands modèles minéralogiques des sols tropicaux (Sols à allophanes (argiles non cristallisées), Sols à argiles 1/1 et Sols à argiles 2/1) et présentant des systèmes culturaux de différents niveaux d’intensification (monocultures intensives destinées à l’exportation, systèmes paysans faiblement intensifiés, etc.) ont ainsi été sélectionnées sur les sols de Martinique. Par ailleurs, afin de limiter les effets des usages antérieurs des parcelles, nous avons généralement choisi des situations culturales âgées au minimum de 3 ans.L’analyse des stocks de carbone des différentes parcelles fait apparaître des comportements différents : dans les sols à allophanes, il y a un effet de la minéralogie sur la stabilisation des matières organiques ; dans les sols à argiles cristallisées, il existe une corrélation entre la teneur en carbone (ou le stock organique) et la texture (ou teneur en éléments fins), aussi bien pour les situations non cultivées que pour les situations sous cultures. L’amplitude des variations (diminution) des stocks en carbone observées sous l’effet de différents modes de gestion des sols, dépend elle aussi de la texture : dans les sols sableux, la potentialité de séquestration du carbone est faible ou nulle, en revanche, les potentialités de stockage du carbone sont plus fortes dans les sols argileux.L’estimation des stocks totaux de carbone à l’échelle de la Martinique, pour un mètre de profondeur et pour une situation moyenne entre les cartes d’usage des terres de 1969/1970 et 1979/1980, s’élèvent à 11,859 Mt de C calculés pour 95,8% de la surface.La distribution de la matière organique du sol varie avec la texture du sol : dans les sols sableux, à faibles teneurs en matière organique, les matières organiques sont principalement associées aux fractions sableuses ; dans les sols argileux, plus riches en matières organiques, 50 à 60 % de la matière organique sont associées à la fraction argileuse. De même, la dynamique de la matière organique dépend également de la texture du sol : dans les sols sableux, les variations des stocks organiques sont essentiellement dues à la perte ou à l’accumulation en carbone de la fraction sableuse ; dans les sols argileux, la fraction argileuse participe de manière prépondérante aux variations des stocks organiques de ces sols lors de leur mise en culture ou en prairie ; les sols sablo-argileux ont un comportement intermédiaire entre ces deux pôles.La stabilité structurale varie avec la minéralogie. Les andosols (ou ALL) présentent un haut degré d’agrégation et de stabilité, du à la présence d’allophanes et à leur association particulière avec les composés organiques. Dans les sols à argiles cristallisées, la stabilité de l’agrégation est plus élevée dans les sols à argiles 1/1 (ou LAC) ; les valeurs les plus faibles sont généralement observées dans les parcelles sur sols à argiles 2/1 (ou HAC). En outre, la mise en culture se traduit généralement par une diminution de la stabilité de l’agrégation.L’intensification des cultures (labours fréquents, faibles restitutions de matière organique au sol, etc.) accentue la perte de la stabilité de l’agrégation provoquée par la mise en culture, en particulier dans les parcelles sur sols à argiles 2/1 (ou HAC)
Soils elements stocks, and particularly those of carbon, are in constant evolution under natural factors effect (climate, vegetation, clays content, etc) and anthropic factors effect (soils uses, etc). Our objective is thus, (i) to better understand the relations between soil, farming system and stored carbon quantity, (ii) to study the consequences of soils uses changes and of soils managements changes on organic matter shapes in soil and (iii) to specify organic matter role on soil properties physics.Representative agri-pedological situations of the three great mineralogical models of tropical soils (allophonic soils (not crystallized clays), 1:1 clay soils and 2:1 clay soils) and presenting agricultural systems of various levels of intensification (intensive monocultures intended for export, slightly intensified farming systems, etc) were thus selected in the soils of Martinique. In addition, to limit the effects of their former uses, we generally chose to the minimum 3 years old farming situations.The analysis of the various lands carbon stocks reveals different behaviors: in allophonic soils, a correlation exists between carbon content (or organic stock) and texture (or fine elements content), as well for not cultivated as for cultivated situations. Variations ranges (reduction) of carbon stocks observed under various management soils systems effect, also depends on texture: in sandy soils, carbon sequestration potentiality is low or null, on the other hand, carbon storage potentialities are higher in clay soils.The estimation of total carbon stocks on the scale of Martinique, for one meter of depth and for and average situation between the use soils charts of 1969/70 and 1979/80, rises to 11,859 Mt of C calculated for 95,8% of the surface.Soil organic matter distribution varies with soil texture: in sandy soils, with low contents of organic matter, organics matters are mainly associated with the sandy fractions; in clay soils, richer in organic matters, 50 to 60% of the organic matters are associated with the argillaceous fraction. In the same way, the organic matter dynamics also depends on soil texture: in sandy soils, organic stocks variations are primarily due to carbon loss or accumulation of the sandy fraction; in clay soils, the argillaceous fraction takes part in a dominating way in organic stocks variations of these soils at the time of their setting in culture or meadow; the sand-clay soils have an intermediate behavior between these two poles.Structural stability varies with mineralogy. Andosols (or ALL) present a high degree of aggregation and stability, due to the presence of allophones and their particular association with the organics compounds. In crystallized clay soils, aggregation stability is higher in 1:1 clay soils (or LAC); the lowest values are generally observed in the lands on 2:1 clay soils (or HAC). Moreover, culture setting generally results in aggregation stability reduction.Cultures intensification (frequent ploughings, low organic matter restitutions to the soil, etc) accentuates aggregation stability loss caused by culture setting, particularly in lands on 2:1 clay soils (or HAC)

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23

Langenbruch, Christina. "Effects of nutrient cycling through litter of different broadleaved deciduous tree species on soil biochemical properties and the dynamics of carbon and nitrogen in soil." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-F1C2-F.

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Silva, Jéssica Caroline dos Santos. "Estoques e fluxos de carbono e nitrogênio acima e abaixo do solo em fragmentos de Floresta Atlântica no sul do Brasil." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-30112017-101614/.

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Florestas tropicais tem um papel relevante nos ciclos globais do carbono e nitrogênio. A Floresta Atlântica é um bioma tropical ameaçado da América do Sul, de imensa complexidade estrutural, mas ainda pouco investigado quanto ao seu funcionamento. Neste contexto, o objetivo principal desse estudo foi investigar a estrutura da floresta através da quantificação da biomassa viva acima do solo e da queda anual de folhas. Paralelamente, as concentrações de carbono e nitrogênio foram determinadas no solo, e na vegetação, permitindo a determinação de estoques e fluxos desses elementos em áreas de diferentes fitofisionomias localizadas nas escarpas da Serra do Mar, na costa nordeste do Estado de Santa Catarina, sul do Brasil. As áreas de estudo localizam-se no município de Joinville, onde a temperatura média anual é de 20°C e a precipitação média acumulada anualmente é de aproximadamente 2200 mm. Os sítios amostrais foram estabelecidos em elevações de 200 m anm (Submontana) e 800 m anm (Montana) Em cada área, quatro parcelas de aproximadamente 0,25 ha foram delimitadas, e, então, foram determinadas a estrutura florestal, biomassa acima e abaixo do solo (viva e morta) e produção de serrapilheira. Concentração e composição isotópica de carbono e nitrogênio em cada compartimento (folhas, tronco, serrapilheira e solo) foram determinadas e usadas para converter biomassa em estoques e fluxos desses elementos, e compreender as complexas interações dentro desses ecossistemas. A AGLB foi de aproximadamente 300 Mg.ha-1 na floresta Submontana e 380 Mg.ha-1 na floresta Montana, AGDB, por sua vez, foi de 6,8 e 6,6 Mgoha-1 e BGB (raízes) foi de 54 e 66 Mg.ha -1, respectivamente. Não foi encontrada diferença significativa entre a produção de serrapilheira entre as fitofisionomias, sendo encontrada uma produção média de 6,4 Mg.ha-1 ano-1 na floresta Submontana e 6,9 Mg.ha-1 ano-1 na Montana. As folhas foram o componente majoritário da serrapilheira, contribuindo com ~68% em ambas as áreas. Os estoques totais de carbono e nitrogênio foram significativamente maiores na fitofisionomia Montana, aumentando de 208 MgC.ha-1 para 390 MgC.ha-1 e de 7 MgN.ha-1 para 16 MgN.ha-1, respectivamente. Fluxos de carbono e nitrogênio via serrapilheira nas florestas Submontana e Montana foram, respectivamente, igual a 3,0 e 3,2 Mg.ha-1 e de 0,12 e 0,14 Mg.ha-1. Valores de ?13C em cada compartimento foram similares entre as áreas, e típico de plantas que seguem o ciclo fotossintético C3. Conforme esperado, um enriquecimento em 13C e 15N ao longo do perfil do solo foi encontrado em ambas as áreas. Valores de ?15N foram maiores em folhas, serrapilheira e solo na floresta Submontana, possivelmente devido à maior disponibilidade de nitrogênio neste sítio; e/ou ao baixo tempo de residência do solo e serrapilheira empobrecida em 15N no sítio Montana. De maneira geral, posições latitudinal (em termos de disponibilidade de luz) e altitudinal (em termos de precipitação e temperatura) foram determinantes na composição, alocação e dinâmica do carbono e nitrogênio nestes ecossistemas
Tropical evergreen forests have a key role in the global carbon and nitrogen cycles. The Atlantic Forest is a vanishing South American tropical biome of immense structural complexity. The structure and functioning of these forests are relatively unknown. In this context, the main objective of this study was to investigate the forest structure by estimating aboveground live biomass (AGLB), belowground biomass (BGB) and litterfall. The determination of carbon and nitrogen concentrations in soils and vegetation allowed to quantify stocks and fluxes of these two elements. Four 0.25 ha-plots were established in two elevations (200 m asl and 800 m asl) in forests located on the slopes of the Serra do Mar, on the northeast coast of the State of Santa Catarina, southern Brazil. The sampling areas are located in the municipality of Joinville. The historical average annual temperature is 20°C and rainfall is approximately 2200 mm. The AGLB varied along the sites from approximately 300 Mg.ha-1 (submontane) to 380 Mgoha-1 (montane), AGDB varied from 6.8 to 6.6 Mgoha-1 and BGB (roots) varied from 54 to 66 Mg.ha -1, respectively. . The average litterfall production of 6.4 Mg.ha-1 ano-1 and 6.9 Mg.ha-1 ano-1 were found in the submontante and montane study sites, respectively. Leaves were the major component of litterfall contributing ~68% in both sites. Total carbon and nitrogen stocks were higher in the montane site. Total carbon stock (AGLB + BGB) increased from 208 Mg.ha-1 in the submontane site to 390 Mg.ha-1 in the montane. While, total nitrogen stock increased from 7 Mg.ha-1 to 16 Mg.ha-1, respectively. Fluxes of carbon and nitrogen via litterfall in the submontane and montane site varied from 3.0 to 3.2 Mg.ha-1 and from 0.12 to 0.14 Mg.ha-1, respectively. ?13C values in each compartment were similar between the two sites, and representative of C3 plants. As expected, there was an enrichment of ?13C and ?15N values in depth in each studied site. ?15N values where higher in leaves, litter and soil of the submontane site, possibly due higher nitrogen availability in this site; or low residence time of soil and depleted 15N in litterfall of the montane site. Overall, latitutinal (in terms of light availability) and altitudinal (in tems of precipitation and temperature) position were determinant in the nitrogen and carbon composition, allocation and dynamics in these ecosystems

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Terefe, Hailu [Verfasser]. "Effects of integrated land management, landscape position and land-use types on soil physicochemical properties, discharge, species richness and carbon stock in Geda watershed, north Shewa, Ethiopia / Hailu Terefe." München : GRIN Verlag, 2021. http://d-nb.info/122744656X/34.

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Guerra, Henrique Pose. "Deposição de palha da cana-de-açúcar e as relações com atributos químicos e físicos do solo." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-04012017-095341/.

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Existe grande demanda pelo etanol de cana-de-açúcar. Para suprir essa demanda, uma forma é o aumento de produtividade pelo etanol de 2ª geração proveniente da palha. A remoção dessa palha pode alterar atributos químicos e físicos do solo. O objetivo deste trabalho foi caracterizar o solo e avaliar os impactos da manutenção de diferentes quantidades de palha de cana-de-açúcar nos atributos químicos e físicos do solo. O experimento foi conduzido próximo a Capivari - SP na unidade Bom Retiro (BR) e próximo a Valparaiso - SP na unidade Univalem (UV). O tipo de solo de cada área experimental foi, respectivamente, Latossolo Vermelho distrófico típico e Argissolo Vermelho-Amarelo distrófico típico. O delineamento utilizado foi blocos ao acaso com seis tratamentos e quatro repetições. Os tratamentos testados foram as seguintes quantidades de palha em Mg ha-1 de massa de matéria seca: BR (0; 3,4; 7,8; 13,0; 16,6; 15,6) e UV (0; 4,2; 8,7; 15,1; 18,9; 23,3). Foram avaliados atributos químicos e físicos tais como teor e estoques de carbono, fracionamento da matéria orgânica dos solos, pH e resistência do solo à penetração. As camadas avaliadas foram diferentes na caracterização (0-10; 10-20; 20-30; 30-40; 40-50; 50-60; 60-80 e 80-100 cm) e após 1 ano de efeito da palha (0-5 e 0-10 cm). Os resultados demonstraram que os solos não apresentavam variações significantes nos teores de macronutrientes e C no momento de implantação dos experimentos, indicando que dentro de cada área experimental o solo era homogêneo e, portanto, adequado para implantação do experimento. Transcorrido um ano de experimento, as diferentes quantidades de palha não alteraram os teores de C (independente da profundidade avaliada) e nem a distribuição das frações da MOS. Desta forma, conclui-se que os efeitos da retirada da palhada de cana-de-açúcar nos atributos químicos e físicos do solo, se existirem, serão expressos em um tempo maior de condução do experimento. Essa consideração pode ser colocada também para pH e resistência à penetração
Globally, there is increasing demand for sugarcane ethanol. To meet this demand, one way is to increase productivity by 2nd generation ethanol using sugarcane straw as feedstock. Straw removal management can change the chemical and physical soil properties. The aim of this study was to characterize the soil and assess the impacts of maintenance of different amounts of sugarcane straw on soil chemical and physical properties. Two experiments were conducted near Capivari - SP in Bom Retiro mill (BR) and close to Valparaiso - SP in Univalem mill (UV). The soil type of each experimental area was, respectively, a Rhodic Kandiudox (USDA Soil Taxonomy) and a Kanhaplic Haplustults (USDA Soil Taxonomy). The experimental design used was a randomized blocks with six treatments and four replications. The treatments were the following amounts of straw in Mg ha-1 of dry matter: BR (0, 3.4, 7.8, 13.0, 16.6, 15.6) and UV (0, 4 2, 8.7, 15.1, 18.9, 23.3). Soil chemical and physical attributes were assessed, such as content and carbon stocks, fractionation of soil organic matter, pH and soil resistance to penetration. Soil sampling was performed for the 0-10; 10-20; 20-30; 30-40; 40-50; 50-60; 60-80 and 80-100 cm layers in the soil characterization (base line) and after 1 year of effect of straw, soil was sampled at 0-5 and 0-10 cm depth. Our results showed that the soils had no significant variation in the macronutrient and C contents and C at the time of implantation of the experiments, indicating that the soil in each experimental area was homogeneous and therefore suitable for implementation of the experiment. After one year of experiment, different amounts of straw did not alter the contents of C (regardless of the assessed depth) nor the distribution of SOM fractions. Thus, we concluded that the effects of the sugarcane straw removal on soil chemical and physical attributes, if any, it should be expressed in a long-term experiment

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Grinand, Clovis. "Suivi et modélisation des changements d’usage des terres et stocks de carbone dans les sols et les arbres dans le cadre de la REDD+ à Madagascar. : vers des mesures pertinentes localement et cohérentes à large échelle." Thesis, Montpellier, SupAgro, 2016. http://www.theses.fr/2016NSAM0030.

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Le changement d’usage des terres, liées à l’agriculture et à la foresterie, engendre une perte importante de biodiversité et représente une part importante de nos émissions de GES à l’origine du changement climatique. Le mécanisme de Réduction des Émissions de la Déforestation et Dégradation des forêts, conservation, gestion durable et restauration des stocks de carbone (REDD+) initié il y a dix ans. peine à se mettre en place du fait de nombreuses contraintes politiques et scientifiques. Malgré l’existence de lignes directrices élaborées par la communauté scientifique internationale, des outils et données sont nécessaires afin de fournir des informations précises, à moindre coût et utilisables à différentes échelles. L’objectif de cette thèse est de développer des méthodologies innovantes pour réduire les incertitudes sur les estimations des émissions et séquestrations de CO2 associées à la déforestation, dégradation et régénération des terres. Madagascar, pays engagé dans le REDD+ depuis huit ans et soumis à des pertes importantes de biodiversité et de couvert forestier est pris comme exemple. Trois études complémentaires ont été réalisées : i) le suivi de la déforestation en région tropical humide et sec par satellites, ii) l’estimation des stocks de carbone dans les sols et les forêts et iii) la modélisation des changements d’usage de terres. Nous avons développé une nouvelle méthodologie de suivi de la déforestation à Madagascar permettant de tenir compte de la définition des forêts et améliorer la prise en compte des petites parcelles de défriche brulis. Les chiffres de la déforestation, variant d’une région à une autre, ont ainsi été actualisés jusqu’en 2013. Une méthodologie innovante de cartographie des stocks de carbone dans le sol à des résolutions fines et à des échelles régionales a été mise au point en couplant de nombreux facteurs environnementaux et un inventaire de terrain à l’aide d’un modèle d’apprentissage automatique. Ce modèle spatial du carbone a été appliqué sur des images satellites acquises vingt année plus tôt afin d’évaluer la dégradation des stocks de carbone du sol et leur régénération potentielle. Des facteurs de perte et gains de carbone dans le sol ont pu ainsi être estimés. Enfin, une approche de modélisation des changements d’usage des terres a permis de mieux comprendre les facteurs biophysiques et socio-économiques liées à la déforestation, dégradation des terres et régénération, et proposer des scénarios spatialisés pour aider les décideurs. Les résultats obtenus dans cette thèse et les méthodologies développées permettent d’alimenter les discussions et documents concernant la stratégie REDD+ de Madagascar. Elle contribue et vise à une meilleure gestion des agro-écosystèmes par la fourniture d’informations spatiales justes, précises spatialement et pertinentes à grande échelle
Land use change due to agriculture and forestry, generates a significant loss of biodiversity and is an important part of our greenhouse gas (GHG) emissions causing climate change. The Reduction of Emissions from Deforestation and Forest Degradation, conservation, sustainable management and restoration of carbon stocks (REDD+) mechanism initiated ten years ago is struggling to establish because of many political and scientific constraints. Despite the existence of guidelines developed by the international scientific community, tools and data necessary to provide accurate, cost and usable at different scales. The objective of this thesis is to develop innovative methods to reduce uncertainties in the estimates of CO2 emissions and sequestrations from deforestation, degradation and land regeneration. Madagascar, a country committed in REDD+ for eight years and subjected to significant losses of biodiversity and forest cover, is taken as an example. Three complementary studies were carried out: i) monitoring of deforestation in tropical humid and dry regions, ii) estimates of carbon stocks in soils and forests and iii) land use change model. We have developed a new methodology for monitoring deforestation in Madagascar considering the national definition of forests and accounted for small plots of slash and burn practices. The figures of deforestation vary from one region to another, and have been updated to 2013. An innovative methodology for soil organic carbon stock mapping at fine resolution and regional scale has been developed by coupling many environmental factors and a field inventory using a machine learning model. This spatial carbon model was applied on satellite images acquired twenty year ago to assess the degradation of soil carbon stocks and potential regeneration. Loss and gain factors due to various land use change were estimated. Finally, the land use change framework developed allowed us to understand the biophysical and socio-economic factors related to deforestation, land degradation and regeneration, and provide spatially scenarios to assist policy makers. The results obtained in this thesis and the methodologies developed allow to feed the discussions and documents relating to the REDD + strategy in Madagascar. It contributes and is aimed at a better management of agro-ecosystems by providing accurate spatial information, locally relevant and globally consistent

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Dlugoß, Verena [Verfasser], Peter [Akademischer Betreuer] Fiener, and Karl [Akademischer Betreuer] Schneider. "Impacts of Soil Redistribution Processes on Soil Organic Carbon Stocks and Fluxes in a Small Agricultural Catchment / Verena Dlugoß. Geographisches Institut, Universität zu Köln. Gutachter: Peter Fiener ; Karl Schneider." Köln : Universitäts- und Stadtbibliothek Köln, 2011. http://d-nb.info/1038064341/34.

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Kyulavski, Vladislav Dimitrov. "Greenhouse gas emissions and soil carbon stocks associated with crop residues and organic fertilizers mixtures in sugar cane cropping systems." Thesis, La Réunion, 2019. https://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/19_27_VDKyulav.pdf.

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Dans le contexte environnemental actuel il est nécessaire d’optimiser l’utilisation des ressources pour réduire les déchets et les émissions de gaz à effet de serre (GES). L’utilisation de ressources renouvelables et le recyclage sont au cœur du modèle d’économie circulaire, selon lequel le déchet est une ressource mobilisable, transformable, réutilisable et par conséquent non limitée. En agriculture, le cercle vertueux de l’économie circulaire peut être mis en place à travers le recyclage des matières organiques en tant que fertilisants et l’adoption d’une approche agroécologique qui privilégie les services écosystémiques pour lutter contre les nuisibles, protéger le sol et augmenter ses stocks de carbone, dont un des exemples est le paillage. Dans la culture de canne à sucre, la paille laissée à la surface du sol, est aussi de plus en plus convoitée par les industriels pour la production d’agrocarburant de seconde génération. L’émergence d’une telle concurrence d’usage de la biomasse et les enjeux environnementaux sous-jacents imposent d’évaluer à la fois les avantages et les inconvénients agronomiques et environnementaux du recyclage conjoint du paillis de canne à sucre et des fertilisants organiques. Les objectifs de ce travail sont donc i) de comparer l’effet des fertilisants de qualité physicochimique contrastée, sur la décomposition d’un paillis de canne à sucre, et ii) d’évaluer les potentialités d’émission de GES des mélanges paillis-fertilisant en fonction de la quantité de paille laissée et de la qualité des fertilisants apportés. La stratégie de recherche adoptée visait dans un premier temps à détecter des interactions carbone/azote lors du recyclage conjoint de la paille et des fertilisants organiques. Nous avons ainsi testé la prédictibilité des dynamiques de minéralisation du C et du N des matières organiques seules, ou en mélange (paille/fertilisant) en laboratoire, par un modèle additif simple et un modèle mécaniste de transformation du carbone et de l’azote dans le sol – CANTIS. Nos résultats ont montré que les deux modèles ont surestimé la minéralisation du C et n’ont pas prédit correctement la minéralisation du N des deux mélanges. Cette interaction antagoniste pour les mélanges a pu être corrigée par l’application d’un facteur de contact dans CANTIS, qui reflète la diminution de la biodisponibilité du C et du N, due à des hétérogénéités de distribution à une échelle fine du sol. Dans un deuxième temps, nous avons effectué des essais au champ (en condition réelles) pour suivre à la fois la décomposition de la paille de canne à sucre en mélange avec des fertilisants organiques et les émissions de GES. La quantité de paille décomposée a été proportionnelle à la quantité initiale laissée et n’a été affectée ni par la quantité de paille initiale, ni par le type de fertilisant apporté. Cette proportionnalité est transposable aux potentialités de stockage de carbone dans le sol et devrait être considérée lors de la mise en place de programmes de séquestration de carbone dans le sol ou lors de l’exportation de la paille pour une utilisation par ailleurs. Le type de fertilisant a un rôle clef sur les émissions de GES à court terme après la fertilisation. Les flux d’émissions moyens de CO2 et de N2O les plus élevés ont été obtenus en appliquant du lisier de porc, qui a une forte teneur en eau et est riche en N minéral. A l’inverse, les cinétiques des émissions de GES des fertilisants solides ont été régis par des facteurs environnementaux, dont certains pourraient être contrôlés, tels que l'apport en eau ou la quantité de fertilisant. L’utilisation de fertilisants organiques est bénéfique lorsqu’ils sont riches en N organique et pauvres en teneur en eau, comme la boue de station d’épuration sèche, mais la minéralisation de l’azote dans ce cas est progressive et nécessite l’élaboration de plans d’épandage spécifiques pour répondre aux besoins des cultures
In the current environmental context, it is crucial to optimize the use of resources to reduce waste and greenhouse gas (GHG) emissions. Renewable resources use and recycling lies at the heart of the circular economy model, in which a waste is a mobilizable, transformable, reusable and therefore renewable resource. In agriculture, the “virtuous circle” of circular economy can be achieved through the recycling of organic wastes as fertilizer and the adoption of an agroecological approach that favors ecosystem services for pest control, soil protection and carbon stocks increase, one of the examples of which is mulching. In sugarcane cropping systems straw left on the soil surface is also increasingly coveted by industrial sector to produce second-generation agrofuels. The emerging competition for biomass use and the underlying environmental issues make it necessary to assess both, the agronomic and the environmental advantages and disadvantages of joint recycling of sugarcane mulch and organic fertilizers. Therefore, the objectives of this work are i) to compare the effect of fertilizers of contrasting physicochemical quality, on the decomposition of a sugarcane mulch, and ii) to evaluate the potential of GHG emissions from mulch-fertilizer mixtures, according to the quantity of straw left and the quality of the fertilizers applied. The research strategy adopted in a first step aimed to detect carbon/nitrogen interactions during the combined recycling of straw and organic fertilizers. We have thus tested the predictability of the mineralization dynamics of C and N of the organic materials alone, or in mixture (straw/fertilizer) in the laboratory, by a simple additive model, and a mechanistic model of carbon and nitrogen transformation in the soil - CANTIS. Our results showed that both models overestimated the C mineralization and did not correctly predict the N mineralization of the mixtures. This antagonistic interaction for the mixtures was corrected by the application of a contact factor in CANTIS, which reflects the bioavailability decrease of C and N, due to distribution heterogeneities at a fine scale within the soil. In a second step, we conducted field trials (under real conditions) to measure both the decomposition of sugarcane straw mixed with organic fertilizers and GHG emissions. The amount of straw decomposed was proportional to the initial amount left and was affected neither by the amount of straw nor the type of fertilizer provided. This proportionality is transposable to the potential for carbon sequestration in the soil and should be considered when setting up carbon sequestration or when exporting the straw for alternative use. The type of fertilizer plays a key role in GHG emissions in the short term after fertilization. The highest average CO2 and N2O emission fluxes were obtained by applying pig slurry, which has a high water content and is rich in mineral N. Conversely, the kinetics of GHG emissions from solid fertilizers have been governed by environmental factors, some of which could be controlled, such as water intake or fertilizer quantity application. The use of organic fertilizers is beneficial when they are rich in organic N and poor in water content, such as dry sewage sludge, but the mineralization of nitrogen in this case is gradual and requires elaboration of a specific application strategies to meet crop needs. A better integration of the interactions between the different N and C sources should be considered, in order to develop modeling as a precise tool for the management of an agroecosystem

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Oliveira, Janaína de Moura. "Carbono no solo em sistemas integrados de produção agropecuária no Cerrado e na transição Cerrado - Amazônia." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/5428.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Integrated crop-livestock (iCL) and integrated crop-livestock-forest (iCLF) systems are pointed out as potential soil carbon sinks. However, there are few scientific studies that evaluated the real contribution of these production systems. This work included two studies. The first was to evaluate soil carbon accumulation and its origin in iCLF in the transition zone of the Cerrado-Amazon biomes; the second aimed to calibrate and validate the CQESTR model for the Cerrado ecosystem and to evaluate the effect of soil management practices, including iCL and various scenarios on soil organic carbon (SOC) over time. For the first study two areas under iCLF (iCLF1 and iCLF3, with one and three rows of Eucalyptus urograndis by hedgerow, respectively) were selected. They were cultivated in this system since 2009 in Nova Canaã do Norte, MT. A continuous pasture was used as reference. Soil samples were taken from eight layers (0.0 to 1.0 m) for the evaluation of the bulk density, texture, total C and N and δ¹³C. The second study was conducted in the Cerrado biome. The evaluated areas (Paddock 4 - P4 and Paddock 5 - P5 has been being managed in iCL since 2000. Bulk density and the organic matter content were determined for the 0.0-0.1 and 0.1-0.3 m layers. The CQESTR is a process based model which simulates the effect of climate, crop rotation and tillage management practices on SOC. The model was calibrated with P5 data and validated with P4 data. Its performance was evaluated using statistical regression analysis and the root mean square deviation (MSD). For the first study, the soil C stocks and isotopic composition were affected by the implementation of the iCLF system. The forest component was an important factor for soil C accumulation for both areas under iCLF. The N can be a limiting factor for C accumulation. We concluded that iCLF affected soil C and N stocks in the short term, however, longer iCLF deployment time would be necessary to elucidate the impact of iCLF in the long-term. In the second study model calibration was performed by adjusting the basic decomposition rate coefficient. The measured and simulated values were significantly correlated with an MSD of 2.11, indicating that the model captured spatial-temporal dynamics of SOC in the topsoil. However, CQESTR underestimated SOC for the 0,1-0,3 m layer, probably due to lack of site specific grass or crop root biomass and distribution data under tropical conditions. Additional calibration is required to improve prediction of SOC stabilization process in the subsoil layers of tropical soils. In the long term (20 years), for the superficial (0,0-0,1 m) soil layer, the model simulated C accumulation in iCL and C loss in soybean/corn grain production system independently of the use of zero-tillage or conventional tillage in either of these systems under Cerrado conditions.
Os sistemas de integração lavoura-pecuária (iLP) e integração lavourapecuária- floresta (iLPF) são apontados como potenciais acumuladores de carbono no solo. Entretanto, ainda há poucos estudos científicos que avaliaram a real contribuição desses sistemas de produção. O presente trabalho incluiu dois estudos para avaliação desses sistemas. O primeiro teve por objetivo avaliar a acumulação e a origem do carbono do solo em iLPF na região de transição dos biomas Cerrado-Amazônia; e o segundo estudo teve por objetivo calibrar e validar o modelo CQESTR para o ecossistema Cerrado bem como avaliar o efeito de práticas de manejo do solo, incluindo iLP e vários cenários no carbono orgânico do solo (COS) ao longo do tempo. Para o primeiro estudo foram selecionadas duas áreas sob iLPF (iLPF1 e iLPF3, sistemas com uma linha e três linhas de Eucalyptus urograndis por renque, respectivamente) cultivadas nesse sistema desde 2009 e uma pastagem no município de Nova Canaã do Norte, MT. Amostras de oito camadas (0,0-1,0 m) foram tomadas para avaliação da densidade, textura, teor de C e N total e δ¹³C. O segundo estudo foi conduzido no bioma Cerrado, em área que vem sendo manejada em iLP desde 2000. Foram avaliadas duas áreas, os Piquete 4 (P4) e Piquete 5 (P5). A densidade do solo e o teor de matéria orgânica foram determinados para as camadas 0,0-0,1 e 0,1-0,3 m. O CQESTR é um modelo de simulação de C baseado em processos que simula o efeito do clima, rotações de cultura e práticas de manejo no COS. O modelo foi calibrado com dados do P5 e validado com P4. Seu desempenho foi avaliado usando análise estatística de regressão e o desvio médio quadrático (MSD). No primeiro estudo, a composição isotópica do solo e os estoques de C foram afetados pela implantação do sistema iLPF. O componente florestal foi importante fator na acumulação de C em ambas as áreas sob iLPF. O N pode ser um fator limitante para a acumulação de C. Conclui-se que o iLPF afeta os estoques de C e N do solo no curto prazo, entretanto, novas avaliações com maior tempo de implantação do iLPF poderiam auxiliar na elucidação do comportamento desses elementos no sistema em longo prazo. No segundo estudo, a calibração do modelo foi realizada pelo ajuste do coeficiente da taxa de decomposição básica. Os valores simulados e medidos foram significativamente correlacionados com um MSD de 2,11, indicando que o modelo capturou satisfatoriamente a dinâmica temporal do COS na camada superficial. Entretanto, o CQESTR subestimou o COS para a camada subsequente 0,1-0,3 m, provavelmente devido às diferenças na biomassa e distribuição de raízes de gramíneas de clima tropical e temperado. Calibração adicional é requerida para melhorar a predição do COS e processos de estabilização nas camadas subsuperficiais de solos tropicais. Para a camada 0,0-0,1 m, em longo prazo (20 anos), o modelo simulou acumulação de C em iLP e decréscimo de C em sistema de produção com sucessão soja/milho, tanto sob plantio direto quanto preparo convencional em condições do Cerrado.

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Manlay, Raphael. "Organic matter dynamics in mixed-farming systems of the West African savanna: a village case study from south Senegal." Diss., Institute of Forestry, Agricultural and Environmental Engineering (ENGREF), 2000. http://hdl.handle.net/10919/71623.

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Organic matter (OM) is a multi-purpose tool in West African smallholder mixed-farming systems, but its supply has been decreasing for several decades. To assess the viability of a mixed-farming system of south Senegal, carbon (C), nitrogen (N) and phosphorus (P; available in soil and noted POD) budgets (stocks and flows) were thus quantified.The village territory of the study showed a ring-like organisation with growing intensification of fertilization and cropping practices from the periphery (bush ring) to the compounds (compound fields).Stocks in plant and soil averaged 54.7 tC, 2.63 tN and 43.5 kgP ha 1 in old fallows. They were 97, 29 and 251 % higher than in the bush cropped fields, plant biomass accounting for nearly all of the rise. C, N and P amounts recorded in the soil of compound fields were higher than those of the bush field, but the increase was restricted mainly to the 0 10 cm layer. However, the rather weak response of local sandy soils to management can be interpreted only by reassessing the bio-thermodynamical signification of soil organic carbon cycling in the maintenance of the integrity of local agroecosystems.Manageable stocks of the whole village territory were estimated to 29.7 tC, 1.52 tN and 28.6 kgP ha 1 in 1997. Carbon was stored mainly in soil. Livestock, crop harvest and wood collecting were responsible for respectively 59, 27 and 14 % of the C uptake on the village territory. As a result, large C flows were set towards the compound ring (3.8 tC ha 1 y 1). N and P depletion of the system amounted to 4 kgN and 1 kgP ha 1 y 1, suggesting that the system was close to nutrient balance.Under current demographic growth rate, C depletion may reach 0.38 tC ha 1 y 1 and C demand may double during the next three decades. Without any intensification of farming practices, the viability of the system might soon be called into question.

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Cambou, Aurélie. "Evaluation du stock et de la stabilité du carbone organique dans les sols urbains." Thesis, Rennes, Agrocampus Ouest, 2018. http://www.theses.fr/2018NSARD086/document.

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Les sols constituent le premier réservoirterrestre de carbone organique et jouent ainsi un rôleclé pour limiter le réchauffement climatique. Les solsurbains représentent 3% du territoire mondial etl’urbanisation est la première cause de changementd’affectation des sols. L’augmentation rapide dessurfaces artificialisées a entraîné un intérêt croissantquant à la capacité des sols urbains à stocker ducarbone. Les travaux de thèse ont visé à comprendrela contribution des sols urbains au stock global decarbone organique et à proposer une méthodestandardisée pour son suivi. Les recherches ont aussiporté sur l’étude de la stabilité du carbone organiquedes sols urbains et la modélisation de la dynamique dece carbone. Une base de données a été construite àpartir de données disponibles au niveau national, puisde mesures supplémentaires acquises dans trois villes françaises.Le stock de carbone des sols ouverts est similaireentre les villes, et équivalent voire supérieur enprofondeur, à celui des sols forestiers environnants.Ce stock dépend plus particulièrement du mode degestion des espaces verts urbains, et de l’histoire dusite. Ainsi, les sols urbains ouverts sont caractériséspar une forte proportion de matières organiqueslabiles sur 0-44 cm de profondeur. Au contraire, lessols scellés présentent des stocks de carbone trèsfaibles. Ils sont caractérisés par une forte proportionde matières organiques stables dont l’évolution(stockage ou minéralisation) dépend de l’état dedormance microbienne. Un modèle conceptuel de ladynamiq
Soils are the largest terrestrial pool oforganic carbon and thus play a key role in mitigatingclimate change. The urban soils account for 3% of theworld’s territory and urbanization is currently theprimary cause of land use change. The increase ofartificial areas have led to a growing interest in theurban soil ability to store organic carbon. This workaimed to understand the contribution of urban soils tothe global organic carbon stock and to propose astandardized method for its monitoring. The researchalso focused on studying the stability of organic carbonin urban soils and modeling its dynamics. A databasewas built using data available at the French territorylevel as well as using additional measurements acquired in three French cities.The organic carbon stock in urban open soils aresimilar between cities, and equivalent, or even higherin depth, than that of surrounding forest soils. Thestock in open soils is particularly dependent upon themanagement methods of the urban green spaces,and on the specific site history. Thus, open urban soilsare characterized by a high proportion of labileorganic matter at 0-44 cm depth. Conversely, sealedsoils have very low carbon stocks. They arecharacterized by a high proportion of stable organicmatter whose evolution (storage or mineralization)depends on the dormant state of the microbialcommunities. A conceptual model of carbon dynamicsfor these two soil types has been developed. Finally,recommendations for optimizing carbon monitoringand urban soil management have been proposed

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Moreira, Cindy Silva. "Estoques de carbono do solo em áreas de reflorestamento: bases para projetos de Mecanismo de Desenvolvimento Limpo." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-29072011-095105/.

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Considerando a grande importância do seqüestro de carbono (C) nos solos florestais, observa-se pequena quantidade de projetos de MDL que incluem esse compartimento como agente da mitigação do aquecimento global. Isso ocorre pelo fato da quantificação dos estoques de C do solo representar maiores desafios se comparada aos demais componentes dos ecossistemas florestais. Sabendo-se das dificuldades econômicas e ambientais envolvidas na adoção desse tipo projeto e da importância das florestas na mitigação da mudança do clima, o objetivo desse trabalho foi avaliar o desempenho de metodologias para a obtenção do estoque de C do solo em duas áreas de reflorestamento e suas respectivas linhas de base (usos do solo anteriores aos plantios, i.e. pastagens e vegetações nativa), como base para diminuir a relação custo-benefício de projetos de MDL. Para alcançar o objetivo principal, a presente pesquisa foi composta das seguintes etapas: (i) estudo da variabilidade espacial do C do solo em uma área de reflorestamento com espécies nativas, estabelecida em Cotriguaçú/MT (Área I) e em uma cronossequência de plantio de eucalipto, localizada em Avaré/SP (Área II); (ii) determinação do tamanho da parcela e do nº ideal de amostras a partir da dependência espacial do C nos reflorestamentos; (iii) estimativa dos teores de C e densidades do solo (Ds) pela Espectroscopia de Reflectância no Infravermelho Próximo (NIRS) e Médio (MIRS), visando a redução dos custos analíticos sem prejuízo da qualidade dos resultados; e (iv) cálculo dos estoques de C do solo nas áreas e estimativa do balanço de carbono do projeto de MDL conduzido na Área II, utilizando a ferramenta EX-ACT (Ex-Ante Carbon Balance Tool). Os resultados obtidos confirmaram a existência de importante variabilidade espacial do C do solo nas áreas e dependência espacial forte em todos os sistemas de manejo estudados. A análise do número ideal de amostras de solo indicou que a coleta de cinco pontos por parcela é tão precisa quanto uma amostragem com mais pontos. O tamanho ideal das parcelas variou de 361-841 m2 nos plantios da Área I e de 900-3721 m2 nos plantios da Área II. O desempenho dos métodos NIRS e MIRS na estimativa do teor de C dos solos foi bastante satisfatório, principalmente quando os modelos testados foram calibrados com quantidades entre 5-10% do conjunto de dados total. Os resultados da estimativa da Ds foram um pouco inferiores aos do C. Os estoques de C do solo obtidos na Área I foram superiores aos da Área II. Considerando apenas o solo, é possível afirmar que o potencial de geração de créditos de C é maior no reflorestamento com espécies nativas sob solo argiloso do que no reflorestamento com eucalipto em solo arenoso. O balanço de C do projeto conduzido na Área I indicou o seqüestro de quase três milhões de toneladas de CO2eq em 40 anos. Espera-se que este estudo contribua para o aumento da inclusão do solo em projetos de MDL, uma vez comprovada a possibilidade de redução dos custos associados à obtenção e determinação dos estoques de C nesse compartimento
Considering the great importance of carbon sequestration (C) in forest soils, there are few CDM projects that include this compartment as an agent of global warming mitigation. This occurs because the quantification of soil C stocks represents a bigger challenge when compared to other components of forest ecosystems. Considering the economic difficulties and environmental issues involved in adopting this type of project and the importance of forests in mitigating climate change, the objective of this study was to evaluate the performance of methods for obtaining soil C stocks in two forestry areas and their respective baselines (land use prior to planting, i.e. pastures and native vegetation) as a basis for reducing the cost-benefit ratio of CDM projects. To achieve the main objective, this research was composed of the following steps: (i) estimating the spatial variability of soil C in an area reforested with native species, established in Cotriguaçú, MT (Area I) and a Eucalyptus chronosequence, located in Avaré, SP (Area II), (ii) determining the optimal amount of soil samples and the plot size from the soil C spatial dependence range in the reforestation areas, (iii) estimating soil C content and bulk density (BD) by Near and Mid Infrared Reflectance Spectroscopy (NIRS and MIRS, respectively) to reduce analytical costs without affecting the quality of the results, and (iv) calculating soil C stocks in both areas and estimating the carbon balance of a CDM Project conducted in Area II, using EX-ACT (\"Ex-Ante Carbon Balance Tool\"). The results confirmed the existence of significant soil C spatial variability in both areas and a strong spatial dependence at all plots. The analysis of the optimal number of soil samples indicated that the sampling procedure with five points per plot is as accurate as intensive sampling. The optimum size of plots ranged from 361-841 m2 at Area I plantations and from 900-3721 m2 at Area II. The performance of MIRS and NIRS to estimate the soil carbon content was very satisfactory, especially when the models were calibrated with amounts between 5-10% of the total data set. The estimations of BD were slightly less precise than those of soil C content. The soil C stocks obtained at Area I were higher than Area II. Considering only the soil compartment, it is clear that the potential for C credit generation in a reforestation with native species on a clayey soil is higher than in a reforestation with eucalyptus on a sandy soil. The C balance of the CDM project conducted in Area I is expected to sequester almost three million tones of CO2 eq in 40 years. We hope this study contributes to the increased inclusion of soil in CDM projects, by confirming the feasibility of reducing the costs associated with both sampling and analytical procedures

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Dang, Thi Thu Huong, and Huu Thu Do. "Biomass and carbon stocks of the natural forests at Me Linh biodiversity station, Vinh Phuc province, Vietnam: Research article." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A29112.

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Biomass and carbon stock of the natural forests in Vietnam are still not clear due to limitation of knowledge and financial. In this paper, the results of estimating biomass and carbon stocks of the natural forests at Me Linh Biodiversity Station are shown. There are two forest types in this study: the forest vegetation restored after shifting cultivation (vegetation type I) and the forest vegetation restored after clear cutting exploitation (vegetation type II). As the results, the estimated biomass of the forest vegetation restored after shifting cultivation is 86.80 ton.ha-1 and the estimated biomass of the forest vegetation restored after clear cutting exploitation is higher, about 131.59 ton.ha-1. The carbon stock in plants was about 43.40 ton.ha-1 of vegetation type I and 65.79 ton.ha-1 of vegetation type II. The carbon storage in soil of vegetation type I is 79.01 ton.ha-1 and vegetation type II is 99.65 ton.ha-1. Hence, the total of carbon stock in forest vegetation I and II are accounted by 122.41ton.ha-1 and 165.44 ton.ha-1, respectively. In general, it can be pointed out that the naturally recovering secondary forest at Me Linh Station is the secondary young forest with the low economic value due to shortly restored process (about 10-20 years), the flora is not rich and abundant, and there are only commonly pioneer and light demanding tree species.
Sinh khối và trữ lượng các bon của rừng tự nhiên ở Việt Nam vẫn ít được quan tâm của do hạn chế về kiến thức và tài chính. Trong bài báo này, chúng tôi đưa ra kết quả của việc ước lượng sinh khối và tổng hợp các bon của các thảm thực vật rừng thứ sinh phục hồi tự nhiên tại Trạm Đa dạng Sinh học Mê Linh, tỉnh Vĩnh Phúc- Việt Nam, nơi có loại hình thảm thực vật chính, đó là thảm thực vật phục hồi sau nương rẫy (kiểu thảm thục vật I) và thảm thực vật phục hồi sau khai thác kiệt (kiểu thảm thực vật II) nhằm mục đích đánh giá tiềm năng của rừng thứ sinh tại khu vực nghiên cứu. Sinh khối của thảm thực vật phục hồi sau nương rẫy là 86,80 tấn/ha. Sinh khối của thảm thực vật phục hồi sau khai thác cao hơn, đạt 131.59 tấn/ha. Lượng các bon hấp thu trong đất của thảm thực vật I là 79,01 tấn/ha và thảm thực vật II là 99,65 tấn/ha. Như vậy, tổng lượng các bon được hấp thu trong mỗi loại hình thảm thực vật trên là: 122,41 tấn/ha (thảm thực vật I) và 165,14 tấn/ha. Nhìn chung, rừng thứ sinh phục hồi tự nhiên tại Trạm Đa dạng Mê Linh chủ yếu là rừng non thứ sinh, ít có giá trị kinh tế do quá trình phục hồi diễn ra ngắn (khoảng 10-20 năm) nên thành phần thực vật nghèo nàn, không phong phú, thành phần chính chủ yếu là các cây gỗ tiên phong, ưa sáng.

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Ribeiro, Paulo Henrique. "Matéria orgânica e atributos químicos em solo de tabuleiros costeiros sob diferentes coberturas vegetais." Universidade Federal do Espírito Santo, 2011. http://repositorio.ufes.br/handle/10/5812.

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Made available in DSpace on 2016-12-23T13:51:53Z (GMT). No. of bitstreams: 1 Paulo Henrique Ribeiro.pdf: 759583 bytes, checksum: c4d8c6d713b57420b683cda1ffa23bed (MD5) Previous issue date: 2011-12-19
A substituição da vegetação nativa por cultivos agrícolas e florestais resulta em modificações nos atributos do solo. Neste trabalho objetivou-se avaliar a dinâmica dos atributos de um Latossolo Amarelo em diferentes coberturas vegetais nos Tabuleiros Costeiros. As amostras de solo foram coletadas nas profundidades de 0-10, 10-20 e 20-40 cm em junho de 2011, em Sooretama, ES, considerando quatro coberturas vegetais: mata nativa, café conilon em monocultivo, café conilon em consórcio com cedro e cacau em consórcio com cedro. O delineamento experimental utilizado foi o inteiramente casualizado em parcelas subdivididas com três repetições. Foram avaliados os seguintes atributos do solo: pH em água; fósforo disponível; potássio, cálcio e magnésio trocáveis; alumínio trocável; acidez potencial; soma de bases; capacidade de troca de cátions efetiva e potencial; saturação por bases e por alumínio; carbono orgânico total (COT); nitrogênio total (NT); carbono orgânico solúvel em água (CSA); relações COT/NT e COT/CSA; matéria orgânica leve; e estoques de COT e NT. Avaliou-se também a serapilheira, e com base na produção de matéria seca e nos teores de nutrientes da mesma, calcularam-se os acúmulos de cada nutriente. Os resultados obtidos foram submetidos à análise da variância e os contrastes comparadas pelo teste F a 1, 5 e a 20 % de probabilidade. Os resultados experimentais mostraram que os sistemas de uso e manejo comportaram-se de forma diferenciada para determinados atributos do solo. A mata foi a cobertura que mais favoreceu o estoque de carbono e nitrogênio no sistema, demonstrado pelos maiores teores de COT e NT, carbono solúvel em água, matéria orgânica leve e acúmulo de serapilheira. Os cultivos agrícolas demonstraram potencial de estocar carbono e nitrogênio no solo. As condições químicas do solo mais adequadas para o desenvolvimento de plantas foram encontradas no solo sob cafeeiro em monocultivo. A elevada acidez, altos níveis de alumínio e baixa disponibilidade de nutrientes no solo sob mata refletiram sua condição natural. Os consórcios agroflorestais apresentaram condição similar para a fertilidade do solo. No entanto, diferenciaram quanto ao acúmulo de serapilheira e nutrientes na serapilheira.
The conversion of native vegetation in agricultural and forest crops results in changes in soil properties. The aimed was to assess the dynamic attributes of a Yellow Oxisol under differents vegetation covers in the Coastal Tableland. Soil samples were collected at depths of 0-10, 10-20 and 20-40 cm in June 2011 in Sooretama, ES, considering four soil vegetation covers: native forest, coffee monoculture, coffee-cedar intercropping, cocoa-cedar intercropping. The experimental design was completely randomized with three replications in split-plot. The following soil atributes were evaluated: water pH; available phosphorus; exchangeable potassium, calcium and magnesium; aluminum; potential acidity; bases content; effective and potential cation exchange capacity; base and aluminum saturation; total organic carbon (TOC); total nitrogen (TN); water-soluble carbon (WSC); C/N and TOC/WSC ratio; light organic matter; TOC and TN stocks. The litter pool was also measured, and based on dry matter yield and nutrient content the same, was calculated the accumulation of each nutrient. The results were submitted to analysis of variance and differences between medium contrasts compared by F-test, verifying a statistical significance (1 and 5%) and trend (20%). The experimental results showed that vegetation covers behaved differently to certain soil attributes. The forest was the cover that most favored the carbon and nitrogen stocks in the soil, demonstrated by higher total organic carbon and total nitrogen, litter pool, water-soluble carbon and light organic matter. Crops demonstrated the potential for carbon and nitrogen stocks in soil. Soil chemical conditions of coffee monoculture were the best for the plant development. The high acidity, high levels of aluminum and low availability of nutrients in the soil under forest reflected its natural condition. The agroforestry consortia had similar condition to soil fertility. However, differed as to litter pool and nutrients in litter

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Courte, Amandine. "Le carbone des sols, la petite agriculture, ses systèmes de production et pratiques, témoins des enjeux environnementaux et agricoles de la Guyane." Electronic Thesis or Diss., Guyane, 2019. http://www.theses.fr/2019YANE0010.

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Les sols guyanais et ceux de l’ensemble du biome amazonien présentent des contraintes édaphiques fortes pour les agrosystèmes, accentuées par les changements d’usage. Les stocks de carbone sont alors au centre des enjeux de fertilité et de gestion environnementale ce qui implique que systèmes et pratiques à faible impact émergent. Notre objectif a été d’estimer l’intérêt de telles pratiques, nous avons étudié l’évolution des stocks après mise en culture en s’appuyant sur les données issues de la création de deux référentiels, celui des systèmes de production de la petite agriculture et celui des stocks de carbone des sols sous végétation naturelle. La prospection dans les systèmes de production agricoles guyanais, a montré que le carbone peut être un indicateur reconnu qui conditionne les modes de gestion de l’espace et confirme le développement spontané de pratiques à faible impact de la part des agriculteurs. Les mesures en milieu forestier et des travaux de spatialisation, indiquent que les stocks de carbone organique des sols sous végétation naturelle sont élevés et pourraient constituer un réservoir de carbone important pour la France, estimé entre 11 et 22 % du stock national. Les mesures de stocks agricoles et les simulations (RothC) du devenir du stock ont souligné que les stocks varient rapidement et fortement après la défriche et la mise en culture. En effet, des décroissances de 50 % de stocks ont été observées avec des systèmes de cultures intensifs en 5 ans. Les pratiques à faible impact portent quant à elles des systèmes de productions efficients au niveau économique mais aussi pour leur intérêt environnemental en étant peu émettrices de GES et en pouvant accroitre le stock du sol de 20 % en 5 ans. Cependant, au-delà de l’acceptation par les agriculteurs, les freins au développement de l’agriculture sont nombreux et nécessitent une prise en compte transversale de ces problématiques par les politiques publiques afin d’encourager les pratiques à faible impact
Guyanese soils as those of Amazonian bioma, have for agrosystems, strong edaphic constrains which are accentuated by land uses changes. Carbon stocks are the center of fertility and environmental management issues that involves emerging systems and low impact practices. In order to estimate the value of such practices, we studied the stocks evolution after cultivation using the data provided by the creation of two repositories, one of the production systems of small-scale agriculture and the other one of soil carbon stocks under natural vegetation. Our study on Guiana's agricultural production systems showed that carbon can be a recognized indicator that order space management patterns. This work also confirms the spontaneous development of low-impact practices by farmers. Measurements in the forest environment and mapping showed that soil organic carbon stocks under natural vegetation are high and could constitute an important carbon reservoir for France, estimated between 11 and 22 % of the national stock. Measurements of agricultural stocks and simulations (RothC) of the stock value among time, indicated that stocks vary rapidly and strongly after clearing and cultivation. Indeed, 50 % stocks decreases have been observed with intensive crop systems after 5 years’ cultivation. Low-impact practices reveal economical and environmental efficiency. In fact, they present an interest by being low GHG emitters and being able to increase the initial SOC under natural vegetation by 20 % after 5 years. However, beyond the farmers acceptability, there are many obstacles for agriculture development and these issues require global public policies in order to encourage these low-impact practices

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Ferreira, Ademir de Oliveira. "Estoque de carbono em áreas pioneiras de plantio direto no Rio Grande do Sul." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/3380.

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The change in land use is an important factor affecting soil C stocks and their distribution in the soil profile. The conversion of native vegetation (NV) for agricultural systems causes a sharp decline in carbon storage in the soil, especially when the soil management is based on intensive and frequent handling and input waste of limited harvest operations. However, the adoption of the preservation system based on minimal soil disturbance and intensive cultivation system can restore levels of soil C stock. Thus , this study aimed to select six pioneer and reference areas of no-till in Rio Grande do Sul, which are now at the stage of consolidated system (>20 years) and paired with nearby native vegetation. This study is divided into three chapters: a) the first evaluated the accumulation and redistribution of carbon in the profile; b) second chapter evaluated key elements in the accumulation of carbon in the surface (0-15 cm) and deep (60-100 cm) layers c) and the third chapter tested the hypothesis that the CSR is affected by soil order and climate type. The main treatments were soil tillage and different cropping systems in two long-term experiments. The implementation of no-till for the six areas ranged from 1978 to 1990, with different textural and mineralogical gradients. Soil samples were collected at five soil depths in a soil profile (0-100 cm). The C content in the soil was determined by dry combustion analyzer using a C/N. The soil C stock was calculated based on the equivalent mass of soil. The principal component analysis (PCA) were performed with the Statistica software version 7 and used a data matrix consisting of 24 variables (attributes of climate, topography and soil surface and subsurface layer). Multiple regressions were also performed to model the C stock in the layer 0-15 and 60-100 cm depth, the method of "Stepwise" selection technique of Forward variables. The statistical regression analyzes were performed using the program JMP iN version 3.2.1 (SALL et al. 2005), using the F test at 5% significance. In chapter 1 data presented indicate that site 1 (Santa Rosa) showed the most reduction in C stock for the conversion of NV to cropping system, ranging 32-39%. C stock surface (0-5 cm) was fully recovered at site 2 (Manoel Viana), site 3 (Palm Missions), site 4 (Lagoa Vermelha) and site 5 (Cruz Alta), with this recovery of 144 % for Typic Quartzipisamment and ranging from 100 to 122% for Oxisols. The biggest changes, with regard to redistribution and increase of carbon storage occurred in the Oxisol, site 4 (Lagoa Vermelha) and 5 (Cruz Alta). There was an increase in the concentrations of particulate organic carbon (POC) in the Lagoa Vermelha and Cruz Alta, sites 4 and 5, across sampled profile relative to NV. In chapter 2 the factors that determined the accumulation of C were different in the condition of subsuperfical layer (60-100 cm) in relation to the surface layer (0-15 cm). In the surface layer (0-15 cm), the saturation of calcium, magnesium, effective cation exchange capacity (CEC) and SOM were positively correlated with the C stock in both no-till and NV. In the subsurface layer (60-100 cm) the attributes that best correlated positively with the C stock in the no-till were altitude and soil organic matter (SOM) in the no-till, and clay, and iron oxides SOM in NV. The highest altitude (801 m) and lower mean annual temperature (16.7°C) favored the accumulation of C stock of surface (0-15 cm) and subsoil (60-100 cm) in no-till. Being that the change in mean annual temperature in the subsurface horizon was more sensitive correlation with the C stock (R2= -0.91) compared to the surface horizon (R2= -0.81). In Chapter 3, the higher CSR and CPI indices were found under treatments with minimum soil disturbance and intensive crop rotation. Lower CSR and CPI values were associated with frequent mobilization and lower crop diversity. These CSR indices sensitively distinguished the intensity of tillage (NT replacing CT) and cropping systems (cover crops replacing winter fallow or crop succession).Therefore, given these results, the combination of the no-till with the intensification of cultivation of long-term systems is an efficient tool for the recovery of soil C, playing a crucial role in productivity, environmental ecosystem and soil quality.
A mudança no uso da terra é um fator importante que afeta o estoque de C do solo e a sua distribuição no perfil. A conversão da CN para sistemas agrícolas provoca uma queda acentuada no estoque de C no solo, especialmente quando o manejo do solo é baseado em operações de manejo intensivo e frequentes e entrada de resíduo da colheita limitado. No entanto, a adoção do sistema de conservação com base na perturbação mínima do solo e sistema de cultivo intensivo pode restaurar em algum nível do estoque de C no solo. Assim, o presente estudo buscou selecionar seis áreas pioneiras e de referência no SPD no Rio Grande do Sul, que hoje estão na fase de sistema consolidado (> 20 anos) pareadas com campo nativo vizinho. Este estudo esta dividido em três capítulos: a) no primeiro foi avaliado o acúmulo e redistribuição de carbono no perfil; b) no segundo capitulo foi avaliado os fatores determinantes no acúmulo de carbono em camada superficial (0-15 cm) e profunda (0-60 cm) desses solos; c) e o terceiro capítulo testou a hipótese de que a RE é afetada por ordem do solo e tipo de clima. Os tratamentos principais foram preparo do solo e diferentes sistemas de cultivo em dois experimentos de longa duração. A implantação das seis áreas sob SPD variou de 1978 a 1990, com diferentes gradientes texturais e mineralógicos. As amostras de solo foram coletadas em cinco profundidades de solo em um perfil de solo (0-100 cm). O conteúdo de C no solo foi determinado por combustão seca usando um analisador de C/N. O estoque de C no solo foi calculado com base na massa de solo equivalente. Foi realizada a análise de componentes principais (ACP) no software Statistica versão 7 e utilizada uma matriz de dados composta por 24 variáveis (atributos de clima, relevo e solo da camada superficial e subsuperficial). Foi realizada ainda uma regressão múltipla para modelar o estoque de C na camada de 0-15 e 60-100 cm de profundidade, pelo método Stepwise , técnica de seleção de variáveis Forward. As análises estatísticas da regressão foram feitas através do programa JMP IN versão 3.2.1 (SALL et al., 2005), utilizando-se o teste F, a 5% de significância. No capítulo 1 os dados apresentados indicam que o local 1 (Santa Rosa) foi o que mais reduziu o estoque de C pela conversão do CN para sistema de cultivos, variando de 32 a 39%. O estoque de C superficial (0-5 cm) foi recuperado integralmente nos locais Local 2 (Manoel Viana), Local 3 (Palmeira das Missões), Local 4 (Lagoa Vermelha) e Local 5 (Cruz Alta), sendo essa recuperação de 144% para o Neossolo Quartzarênico e variando de 100 a 122 % para os Latossolos argilosos. As maiores alterações, no que diz respeito à redistribuição e incremento de estoque de C, ocorreram no Latossolo dos locais 4 (Lagoa Vermelha) e 5 (Cruz Alta). Houve incremento nas concentrações de COP nos locais de Lagoa Vermelha e Cruz Alta em todo perfil amostrado em relação ao CN. No capitulo 2 os fatores que determinaram o acúmulo de C foram diferentes na condição da camada subsuperfical (60-100 cm) em relação à camada superficial (0-15 cm). Na camada superficial (0-15 cm), a saturação de cálcio, magnésio, CTC efetiva e MOS foram fatores correlacionados positivamente com o estoque de C tanto em SPD como em CN. Na camada subsuperficial (60-100 cm) os atributos que melhor se correlacionaram positivamente com o estoque de C no SPD foram altitude e MOS no SPD, e a argila, MOS e óxidos de ferro no CN. A maior altitude (801 m) e a menor temperatura média anual (16,7 ºC) favoreceram o acúmulo de estoques de C superficial (0-15 cm) e subsuperficial (60-100 cm) no SPD. Sendo, que a mudança de temperatura média anual no horizonte subsuperficial teve correlação mais sensível com o estoque de C (R2= -0,91) em relação ao horizonte superficial (R2= -0,81). No capitulo 3, os índices de RE e CPI mais elevados foram encontrados sob tratamentos com perturbação mínima do solo e rotação de culturas intensivas. Valores de RE e CPI baixos estavam associados a mobilização frequente e menor diversidade de culturas. Estes índices de RSE sensibilidade distinguiu a intensidade de plantio direto (PD substituindo PC) e sistemas de cultivo (culturas de cobertura de inverno substituindo sucessão pousio ou cultura). Portanto, diante desses resultados, a associação do SPD com a intensificação de sistemas de cultivo de longo prazo é uma ferramenta eficiente para a recuperação do C no solo, desempenhando um papel crucial na produtividade do ecossistema, ambiental e de qualidade do solo.

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Prays, Nadia [Verfasser], Martin [Akademischer Betreuer] Kaupenjohann, Uwe [Akademischer Betreuer] Franko, Martin [Gutachter] Kaupenjohann, Christof [Gutachter] Engels, and Uwe [Gutachter] Franko. "Effects of biogas residues on yield formation and soil organic carbon stocks / Nadia Prays ; Gutachter: Martin Kaupenjohann, Christof Engels, Uwe Franko ; Martin Kaupenjohann, Uwe Franko." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/1160593477/34.

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Hickmann, Clério. "Efeitos do manejo em propriedades físicas e no carbono orgânico total de um argissolo vermelho-amarelo localizado na Zona da Mata Mineira." Universidade Federal de Viçosa, 2009. http://locus.ufv.br/handle/123456789/5420.

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Made available in DSpace on 2015-03-26T13:53:08Z (GMT). No. of bitstreams: 1 texto completo.pdf: 934885 bytes, checksum: 0e8b335460f18fcf2514e533a07c71bf (MD5) Previous issue date: 2009-04-24
Fundação de Amparo a Pesquisa do Estado de Minas Gerais
When the replacement of natural ecosystems for agroecosystems occurs, generally it is perceived a physical deterioration and a decline in soil carbon content. This degradation can be attributed to intensive soil tillage, exposing it to the action of climatic factors, causing erosion, mineralization of organic matter and oxidation of organic carbon in soil. The use of conservation practices for soil management has received much attention nowadays, primarily with regard to the maintenance and improvement of physical, chemical and biological properties of cultivated soils, and its implications in crop yield. Based on the assumption that the conservation systems improve conservation of soil physical quality, this study aimed to evaluate the changes caused in the physical properties and organic carbon, under different management systems, in a Red-Yellow Argisol, subjected to a long term experiment. For this, samples were collected from the soil layers 0-5, 5-10, 10-20 and 20-40 cm in depth in an experiment involving four treatments, as follows: NT (no-tillage), DP (disc plow); DP + HH (disc plow + heavy harrow) and HH (heavy harrow). An area under secondary atlantic forest (SF), adjacent to the experiment, was sampled and used as reference, representing the fifth treatment. It were evaluated the soil bulk density, particle density, flocculation degree, water dispersible clay, granulometry, porosity, saturated soil hydraulic conductivity, aggregate stability, total organic carbon, organic carbon stocks, organic carbon in aggregate classes and micromorphological analysis of aggregates. It was concluded that: (I) cultivation of the soil increased physical degradation, as evidenced by the reduction of porosity, aggregate stability, saturated soil hydraulic conductivity and increased soil bulk density, (II) the largest carbon stocks were observed in the soil of the secondary atlantic forest (SF) when compared to the soil from the management systems, (III) the conservation management system no-tillage (NT) contributed to the improvement in physical properties and the recovery of organic carbon stocks after about 80 years of agricultural practices, (IV) macroagregates contribute effectively in the organic carbon stocks in soil, showing the highest content of total organic carbon, (V) the microstructural analysis was shown to be sensible among the management systems evaluated, serving as a promising tool for the study of soil aggregation.
Quando ocorre a substituição de ecossistemas naturais por agroecossistemas, geralmente percebe-se a degradação física e declínio do conteúdo de carbono no solo. Essa degradação pode ser atribuída ao intenso revolvimento do solo durante o preparo, expondo-o à ação de fatores climáticos, provocando erosão, mineralização da matéria orgânica e oxidação de carbono orgânico do solo. A utilização de práticas conservacionistas de manejo do solo tem recebido grande ênfase atualmente, basicamente no que se refere à manutenção e à melhoria das propriedades físicas, químicas e biológicas dos solos cultivados e suas implicações no rendimento das culturas. Partindo-se da hipótese de que os sistemas conservacionistas melhoram a qualidade física do solo, o presente trabalho teve como objetivo avaliar as modificações provocadas nas propriedades físicas e no carbono orgânico, em diferentes sistemas de manejo, em um Argissolo Vermelho-Amarelo, submetido a um experimento de longa duração. Para tal foram coletadas amostras de solo nas camadas 0-5, 5-10, 10-20 e 20- 40 cm de profundidade num experimento submetido a quatro tratamentos, a saber: PD (plantio direto); AD (arado de disco); AD+GP (arado de disco+grade pesada) e GP: grade pesada. Uma área sob mata atlântica secundária (MS), adjacente ao experimento, foi amostrada e utilizada como referência, representando o quinto tratamento. Foram avaliados a densidade do solo, densidade da partícula, grau de floculação, argila dispersa em água, granulometria, porosidade, condutividade hidráulica do solo saturado, estabilidade de agregados, carbono orgânico total, estoque de carbono orgânico, carbono orgânico em classes de agregados e análise micromorfológica de agregados. Concluiu-se que: (I) o cultivo do solo aumentou a degradação física, comprovada pela redução da porosidade, da estabilidade de agregados, da condutividade hidráulica em solo saturado e aumento da densidade do solo; (II) os maiores estoques de carbono foram observados no solo da mata atlântica secundária (MS) em comparação ao solo dos sistemas de manejo; (III) o sistema de manejo conservacionista plantio direto (PD) contribuiu para a melhoria nas propriedades físicas e na recuperação dos estoques de carbono orgânico após aproximadamente 80 anos de práticas agrícolas, (IV) os macroagregados contribuem efetivamente nos estoques de carbono orgânico no solo, mostrando os maiores conteúdos de COT; (V) a análise microestrutural se mostrou sensível entre os sistemas de manejos avaliados, servindo de ferramenta promissora para estudo de agregação do solo.

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Lin, Meimei. "Agricultural Intensification across the Midwest Corn Belt Region." Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1437751066.

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de, Blécourt Marleen Verfasser], Rainer [Akademischer Betreuer] Brumme, Edzo [Akademischer Betreuer] Veldkamp, and Dirk [Akademischer Betreuer] [Hölscher. "Impacts of land use and biophysical properties on soil carbon stocks in southern Yunnan, China / Marleen de Blécourt. Gutachter: Edzo Veldkamp ; Dirk Hölscher. Betreuer: Rainer Brumme." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1065881991/34.

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Xavier, Alfredo Augusto Pereira. "Avaliação do acúmulo e emissão de carbono do solo sob sistemas produtivos de pastagem." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-10122014-101014/.

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O manejo adequado do solo é de suma importância na incorporação da matéria orgânica no mesmo, sequestrando carbono da atmosfera. Neste trabalho avaliaram-se dois manejos do sistema produtivo da pecuária, em pastagens de Brachiaria decumbens: (A3) pastagem em recuperação, onde nitrogênio foi aplicado, e (A4) pastagem degradada, onde nenhum tipo de correção é efetuado. Utilizou-se uma área de Mata Atlântica (MT) próxima ao experimento como referência. O foco principal do trabalho foi o acúmulo de carbono no solo e a emissão de CO2. A partir dos teores de carbono e valores de densidade foram estimados os estoques de carbono (ECs), em superfície (0-30 cm) e em profundidade (0-100 cm), em cada um dos sistemas, aplicando as correções por massa equivalente e por teores de argila. Para a estimativa de emissão de CO2 dos solos utilizou-se um sistema portátil que monitora o fluxo de CO2 no interior da câmara através de espectroscopia de absorção no infravermelho. Os resultados mostraram que o sistema A3 acumulou o maior EC, com 142 Mg ha-1, enquanto aproximadamente 99 Mg ha-1 foi obtido para o sistema A4. Na mata o EC foi de 115 Mg ha-1. Os dados de respiração do solo mostraram situação similar para ambas as áreas de pastagem. Outra proposta desse trabalho foi avaliar a qualidade da matéria orgânica do solo (MOS) utilizando a espectroscopia de fluorescência induzida por laser (LIFS). Observou-se o aumento do grau de humificação da MOS (HFIL) com o aumento da profundidade. Os menores valores de humificação foram obtidos na área em recuperação, indicando certa fragilidade deste estoque de carbono ser perdido caso a área não seja bem manejada. Avaliou-se também o potencial da espectroscopia de emissão óptica com plasma induzido por laser (LIBS) para a quantificação de carbono total em solos. Os dados dos teores de carbono obtidos por análise elementar foram utilizados para a calibração do sistema LIBS de acordo com a textura dos solos. O coeficiente de correlação entre os valores de referência (CHNS) e os valores preditos por LIBS na validação foi de 0,87 (erro ~ 25%) para textura arenosa e 0,92 (erro ~ 16%) para textura argilosa. Este trabalho demonstrou a importância do manejo adequado para recuperação de pastagens no Brasil e o risco de se perder esse carbono para atmosfera devido à alta labilidade do carbono armazenado. As pastagens bem manejadas podem levar este sistema produtivo a patamares ambientalmente sustentáveis e contribuir para mitigação do efeito estufa. As técnicas fotônicas apresentaram potencial para determinação de carbono no solo e avaliação de sua estrutura química. Desta forma, espera-se que futuramente este tipo de instrumentação possa ser aplicada ao campo, fornecendo parâmetros que ajudem na tomada de decisões para um desenvolvimento agrícola sustentável.
Proper soil management is important to organic matter incorporation, sequestering carbon from atmosphere. This study was developed for two livestock managements: (A3) pasture recovering of Brachiaria decumbens, where nitrogen is applied, and (A4) degraded pasture of Brachiaria decumbens, with no correction. The reference system was a native forest area (Brazilian Atlantic Forest) next to the experiment. This study aims to compare the soil carbon accumulations and CO2 emissions for both productive systems. Soil carbon content and soil bulk density values were measured to calculate carbon stocks (CSs) in surface (0-30 cm) and at depth (0-100 cm) in each system, applying equivalent mass and clay content corrections. CO2 emissions were estimated using a portable system, which monitors the CO2 flux within a chamber through infrared absorption spectroscopy. The soil carbon stocks were estimated around 142 Mg ha-1 for A3 and 99 Mg ha-1 for A4, while around 115 Mg ha-1 was found in the forest. The results for CO2 emission showed a similar situation for both pasture areas. Another purpose of this study was to evaluate the soil organic matter (SOM) quality using laser-induced fluorescence spectroscopy (LIFS). An increasing of humification degree of SOM (HLIF) was observed with increasing of depth. The lowest HLIFS values were obtained for the recovering area, indicating a certain fragility of carbon stocks, which can be lost if the area is not well managed. In addition, Laser-induced breakdown spectroscopy (LIBS) was used for total soil carbon quantification. Using the data from elemental analysis, mathematical models were developed to calibrate the LIBS system for each class of soil texture. For carbon quantification, the correlation between reference technique (CHN) and LIBS prediction was 0.87 for sandy soils (error around 21%) and 0.92 for clayed soils (error around 16%). This study demonstrated the importance of pasture recovering in Brazil from the point of view of soil carbon sequestration, and the risk of this stock to be lost due to high lability of stored carbon. Well-managed pastures can lead this production system to environmentally sustainable levels and contribute to mitigate the greenhouse effect. Systems with high potential for portability to determine soil carbon and evaluation of its chemical structure have been successfully tested. Thus, it is expected that in a near future, this kind of instrumentation can be effectively applied in the field and provide parameters that help in the decision making for a sustainable agricultural development.

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Mello, Francisco Fujita de Castro. "Estoques de carbono do solo na mudança de uso da terra para o cultivo de cana-de-açúcar na região Centro Sul do Brasil." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-04092013-142011/.

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O Brasil se destaca como o maior produtor de cana-de-açúcar do planeta. Como resultado do aumento da demanda de açúcar e etanol, cerca de 4 milhões de hectares foram convertidos em áreas de cana-de-açúcar nos últimos 10 anos. Espera-se que outros 6 milhões de hectares sejam convertidos nos próximos 10 a 20 anos para suprir a demanda nacional de derivados dessa cultura. Estas modificações podem ocasionar a emissão de gases do efeito estufa, resultantes principalmente da decomposição da matéria orgânica do solo, o que pode levar a dívida de carbono. Por outro lado, a substituição de áreas degradadas pelo cultivo da cana-de-açúcar pode acarretar no incremento dos estoques de carbono dos solos promovendo o sequestro de carbono. O principal objetivo foi proceder a metodologia proposta pelo Painel Intergovernamental de Mudanças Climáticas (IPCC) da Organização das Nações Unidas para avaliar o impacto ocasionado pela expansão do cultivo da cana-de-açúcar sobre a matéria orgânica do solo e seu resultado em emissão de CO2 ou em sequestro de carbono. O total de 142 situações de campo foram avaliadas na região Centro Sul do Brasil, onde a cana-de-açúcar vem substituindo outros usos da terra gerando o total de 6318 amostras de solo que foram analisadas considerando as três principais conversões existentes para cana-de-açúcar no país: i) Cerrado; ii) Pastagens e iii) Áreas de cultivo anual. Os resultados obtidos indicam o decréscimo dos estoques de carbono dos solos quando o cultivo de cana-de-açúcar substitui o cerrado e áreas de pastagens, e promove o incremento quando áreas de culturas anuais são substituídas. Os fatores de mudança de uso da terra referente ao período de 20 anos após a conversão de cerrado para cana-de-açúcar referente às camadas 0-30 cm, 0-50 cm e 0-100 foram respectivamente 0,79 (±0,04), 0,86 (±0,04) e 0,94 (±0,04). Para a conversão de pastagens para o cultivo de cana-de-açúcar, os fatores de impacto de mudança de uso da terra foram 0,91 (±0,04), 0,94 (±0,04) e 0,98 (±0,04), e para a conversão de áreas de cultivo anual os fatores de impacto de mudança de uso da terra foram 1,20 (±0,18), 1,20 (±0,18) e 1,21 (±0,18). O período de compensação da dívida de carbono gerada foi estimado entre 3,5 a 6,3 anos considerando a substituição de cerrado, 1 a 2 anos para áreas convertidas de pastagens e zero para áreas oriundas de cultivo anual, onde não foi observada dívida de carbono. Espera-se que os resultados gerados por este trabalho de pesquisa possam subsidiar os tomadores de decisão como forma de desenvolver políticas apropriadas para a expansão do cultivo da cana de açúcar na região Centro Sul do Brasil promovendo desenvolvimento com baixo impacto ao meio ambiente
Brazil figures as the major sugarcane producer in the world and as result of increasingly demand for sugar and ethanol about 4 millions of hectares were converted into sugarcane systems on last 10 years and others 6 millions of hectares are expected to be converted in next 10 to 20 years. This modification can increase greenhouse gas emissions as result of soil organic matter decomposition and lead to a carbon debt. The aim of this research paper was to perform the IPCC\'s Tier 2 approach to evaluate the impact of sugarcane expansion over the soil organic matter, and their results in CO2 emissions or soil carbon sequestration. A total of 142 field situations were studied in South-Central Brazil where sugarcane substituted other land uses, providing 79 comparison pairs and 6,318 soil samples that were analyzed considering three major conversions to sugarcane: i) Cerrado (Brazilian savannah); ii) Pastures; iii) Annual Cropland (maize or soybean). Our results indicate the decrease of soil carbon stocks when sugarcane overcomes cerrado and pastures, and an increase when annual cropland is replaced. The land use change impact factors after 20 years of conversion from cerrado to sugarcane for 0-30 cm, 0-50 cm and 0-100 cm layers were respectively 0.79 (±0.04), 0.86 (±0.04) and 0.94 (±0.04). For sugarcane replacing pastures the impact factors were 0.91 (±0.04), 0.94 (±0.04) and 0.98 (±0.04), and for the conversion from annual agriculture impact factors were 1.20 (±0.18), 1.20 (±0.18) and 1.21 (±0.18). The repay time for the carbon debt was estimated in 3.5 to 6.3 years considering the substitution of cerrado, 1 to 2 years for areas coming from pastures and zero for areas coming from cropland, where no carbon debt was found. We expect that results of this research paper can subsidize appropriate policies for sugarcane expansion in South-Central Brazil, promoting development with a lower environmental impact

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Soares, Ricardo. "Agregação e distribuição da matéria orgânica em solos de terra preta de índio da Amazônia Central." Niterói, 2017. https://app.uff.br/riuff/handle/1/4788.

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Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ
Existe o consenso de que as Terras Pretas de Índio (TPI) Amazônicas são extremamente eficientes em reter grandes quantidades de Matéria Orgânica do Solo (MOS), e por longo tempo. Porém, os efeitos sobre as Substâncias Húmicas e as Frações Físicas do Solo nestes ambientes tropicais, assim como o estado de agregação influenciado pela MOS de origem pirogênica são pouco conhecidos. O objetivo deste trabalho foi avaliar as alterações na agregação de solos antropogênicos e na distribuição das frações orgânicas do solo de origem Antropogênica e não Antropogênica, do Estado do Amazonas, Brasil. Este estudo foi realizado em cinco argissolos sob florestas secundárias de diferentes idades, sendo dois solos caracterizados como TPI, e os restantes argissolos convencionais. Os resultados mostraram que o solo de uma das áreas de TPI (P02) apresentou os maiores valores de agregados estáveis em água, pouco diferindo estatisticamente da outra área amostrada de TPI (P01). O solo da área P02 foi o que apresentou os maiores: Diâmetro Médio Ponderado (DMP), Diâmetro Médio Geométrico (DMG), Índice de Estabilidade de Agregados (%IEA) e a porcentagem de agregados maior que 2.00 mm, indicando que o maior tempo de pousio, proporcionou um incremento no tamanho dos agregados e na qualidade estrutural do solo. Quanto ao Carbono Orgânico Total (COT), ao se comparar as cinco áreas (P01, P02, P03, P04 e P05), constatou-se a hegemonia das TPI’s em reter mais MOS, do que em solos não antropogênicos, o que é corroborado pelos estoques de carbono. O Fracionamento Químico da MOS mostrou-se eficaz na diferenciação do tipo de solo, verificando-se um maior teor do carbono da fração Humina no solo de TPI da área P02, pouco diferindo estatisticamente da área P01. As distribuições do peso das Frações Leves também diferiram significativamente entre os tipos de origem do solo. As áreas de TPI apresentaram os maiores valores da Fração Leve Livre e Intra-Agregado quando comparadas com as áreas não antropogênicas, demonstrando haver uma maior proteção física das Frações Leves neste sistema. O conteúdo de carbono e nitrogênio Total das frações leves foram maiores nas áreas de TPI, do que nas áreas não antropogênicas. A área P02 foi a que apresentou a melhor qualidade ambiental e menor estado de degradação, devido à qualidade e quantidade da MOS nela contida.
There is consensus that the black soils of Amazonian known as Terras Pretas de Índio (TPI) are extremely efficient in retaining great quantities of soil organic material (SOM), for long periods of time. However, various important characteristics of TPIs are little known: the distribution of organic matter between humic fractions, and between physical fractions, as well as any change in state of soil aggregation due to SOM of pyrogenic origin. The object of this work is to evaluate and compare the states of aggregation and the distributions of organic fractions in soils of anthropogenic (TPI) and non anthropogenic origin from the State of Amazonas, Brazil. This study was made using soil samples from five areas of the soil type classified as "argissolo" under Brazilian soil classification, two of them TPIs and three which exhibited no evidence of anthropogenic alteration. One of the TPIs (P02) had greater proportions of aggregates stable in water and the other TPI (P01) was little different, statistically, from this. The P02 soil aggregates had the greatest pondered mean diameter (PMD), geometric mean diameter (GMD), fraction with diameter > 2mm, and aggregate stability index (%ASI), indicating that a greater undisturbed time had led to this greater structuring. The TPIs had much higher total organic carbon contents (TOCs) than the other soils, a result which was corroborated by their determined carbon stocks. Chemical fractionation of organic matter also distinguished the TPIs from the other soils, the humin fraction being higher in the TPIs, especially P02. Physical fractionation also showed differences in the distribution of organic matter. The TPI soils had higher fractions of free light material and intra-aggregate light material, compared with the non anthopogenic soils, demonstrating that protection of organic matter was greater in the TPI soils. The carbon and nitrogen contents of the light fractions from the TPIs were greater than those of the comparison soils. The P02 soil exhibited the best environmental quality, principally because of its high SOM content.

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Guimarães, Gabriel Pinto. "Impactos de sistemas de manejo do cafeeiro sobre a matéria orgânica e atributos físicos do solo no Território do Caparaó ES." Universidade Federal do Espírito Santo, 2012. http://repositorio.ufes.br/handle/10/6570.

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Research assessing the impact of different management systems of coffee is essential to determine the chemical and physical characteristics of the soil. Starting from the hypothesis that the major input of organic matter improves the physical and chemical quality of soil, the present study was to evaluate the impact of production systems for organic coffee and organic planted with trees in the different fractions of SOM, TOC stocks and NT and physical attributes in two clayey, dystrophic Red-Yellow Latosol (Oxisol) belonging to the Territory to the Carapaó- ES, Brazil. In property 1, located in a district of Santa Clara, city of Iúna-ES, evaluated the following systems: primary forest (MP1), organic coffee (ORG1) and conventional coffee (CON1). The property 2, located in the city Irupi-ES, the systems evaluated were: secondary forest (MS2), intercropping with organic coffee and inga (ORG/IN2), intercropping with organic coffee and leucaena and inga (ORG/IN/LE2), intercropping with organic coffee and cedar (ORG/CED2) and conventional coffee (CON2). Soil samples were collected in canopy projection depths 0-10, 10-20, 20-40, 40-60 and 60-100 cm. The TOC and C stocks reflected the history of management in relation to forest areas, with greatest impact in the 0-10 cm. At this depth, for a property 1, the reductions in TOC relative to primary forests were 34 and 55% respectively for organic coffee and conventional coffee, for the property 2, the reductions in TOC compared to secondary forest were 23% for organic coffee intercropping and 35% for conventional coffee. However, the organic managements increased by 45% in the property 1 and 35% in the property 2 the TOC content compared to conventional coffee in the 0-10 cm. For NT, the mean reductions in relation to primary forest were 45 and 55% respectively for organic coffee and conventional coffee at 0-10 cm depth. On the property 2 there was no difference between coffee and forest systems, however, organic systems had higher stocks and levels that the conventional coffee at all depths, with 51% increased level of NT at 0-10 cm. The accumulated C stocks were reduced in coffee systems in 28.6% and 17.4% respectively in relation to primary and secondary forests. The stocks N tended to follow the C stocks in a property 1, however, the organic coffee consortium with N stocks presented near the forest and higher the conventional coffee. The management of coffee caused a reduction in the different compartments of C studied. The forest areas showed better physical quality of soils in relation to coffee systems, however the organic systems showed improvement in soil physical quality compared to conventional management, reflected by the highest degree of floculation, aggregation, moisture and lower resistance soil penetration
Pesquisas avaliando o impacto de diferentes sistemas de manejo do cafeeiro são essenciais para determinação da qualidade química e física do solo. Partindo da hipótese que o maior aporte de matéria orgânica melhora a qualidade química e física do solo, a presente pesquisa teve por objetivo avaliar o impacto de sistemas de produção de cafeeiro orgânico e orgânico arborizado nas diferentes frações da MOS, estoques de COT e NT e atributos físicos em dois Latossolo Vermelho- Amarelo Distrófico argiloso do Território do Caparaó- Espírito Santo. Na propriedade 1, localizada no distrito de Santa Clara, município de Iúna, foram avaliados os seguintes sistema: mata primária (MP1), café orgânico (ORG1) e café convencional (CON1). A propriedade 2, localizada no município Irupi, os sistemas avaliados foram: mata secundária (MS2), café orgânico consorciado com ingá (ORG/IN2), café orgânico consorciado com ingá e leucena (ORG/IN/LE2), café orgânico consorciado com cedro (ORG/CED2) e café convencional (CON2). As amostras de solo foram coletadas na projeção da copa nas profundidades 0-10, 10-20, 20-40, 40-60 e 60-100 cm. O COT e estoque de C refletiram o histórico de manejo em relação às áreas de mata, com maior impacto na camada 0-10 cm. Nesta profundidade, para a propriedade 1, as reduções no COT em relação a mata primária foram de 34 e 55 % respectivamente para cafeeiro orgânico e cafeeiro convencional, para a propriedade 2, as reduções no COT em relação a mata secundária foram de 23% para cafeeiros orgânicos consorciados e 35% para cafeeiro convencional. No entanto, os manejos orgânicos aumentaram em 45 % na propriedade 1 e 35% na propriedade 2 o teor de COT em relação ao cafeeiro convencional na camada 0-10 cm. Para o NT, as reduções médias em relação à mata primária foram de 45 e 55 % respectivamente para cafeeiro orgânico e cafeeiro convencional na profundidade 0-10 cm. Na propriedade 2, não ocorreu diferença entre sistemas cafeeiros e mata, no entanto, os sistemas orgânicos apresentaram teores e estoques superiores que o cafeeiro convencional em todas as profundidades,sendo de 51% o aumento do teor de NT na camada 0-10 cm. Os estoques de C acumulado foram reduzidos nos sistemas cafeeiros em 28,6% e 17,4 % respectivamente em relação às matas primária e secundária. Os estoques de N tenderam a acompanhar os estoques de C na propriedade 1, no entanto, os consórcios com cafeeiros orgânicos apresentaram estoques de N próximos ao da mata secundária e superiores que o cafeeiro convencional. O manejo do café acarretou redução nos diferentes compartimentos de C estudados. As áreas de mata apresentaram melhor qualidade física do solo em relação aos sistemas cafeeiros, no entanto os sistemas orgânicos apresentaram melhoria na qualidade física do solo em relação ao manejo convencional, refletido pelos maiores valores de grau de floculação, agregação, umidade e menor resistência do solo à penetração

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Assmann, Joice Mari. "Estoque de carbono e nitrogênio no solo e ciclagem de nutrientes em sistema de integração soja-bovinos de corte em plantio direto de longa duração." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/90502.

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Sistemas integrados de produção agrícola e pecuária estão sendo cada vez mais adotados no país e existe um grande potencial, no subtrópico brasileiro, de integrar a pecuária nas grandes extensões de pastagens hibernais cultivadas, antecedendo lavouras de verão, como soja e milho. Nesses sistemas, enquanto o animal é considerado o elemento catalizador e o solo é o compartimento que centraliza e captura as modificações impostas pelo manejo. Neste estudo, investigou-se um sistema com produção de soja-bovinos de corte, em um consórcio de azevém + aveia preta, manejada em diferentes alturas de pastejo (10, 20, 30, 40 cm) e uma área sem pastejo. O experimento foi instalado em maio de 2001, em São Miguel das Missões - RS, em Latossolo Vermelho distroférrico, em sistema plantio direto. Foram abordados aspectos relacionados aos impactos do manejo do sistema sobre os teores e os estoques de carbono e nitrogênio após nove anos da instalação do experimento. Também foi estudada a cinética de liberação de carbono, nitrogênio, fósforo, potássio, cálcio e magnésio, em dois ciclos pastejo-soja (2009/11), a partir da decomposição dos resíduos vegetais, em sacos de decomposição (litter bags). Intensidades de pastejo moderadas a leve (20, 30 e 40 cm de altura do pasto) promoveram aumento nos teores e estoques de carbono orgânico e nitrogênio, total e particulado, semelhantemente ao observado na área sem pastejo. Valores do índice de manejo de carbono (IMC), em comparação com os da área tomada como referência (mata nativa e SP), indicam alta degradação da qualidade da matéria orgânica na maior intensidade de manejo (10 cm). A velocidade da ciclagem dos nutrientes foi maior nas intensidades moderadas de pastejo (20 e 30 cm), tanto dos resíduos da pastagem como do esterco. A decomposição dos resíduos da soja, cultivada na sequência, não foi afetada pelo manejo do pasto. As folhas apresentaram uma decomposição mais rápida, e consequente liberação mais rápida de nutrientes, em relação aos caules. A quantidade de nutrientes liberados dos resíduos em um ciclo pastejo-soja é suficiente em relação à demanda das plantas (pastagem e soja) e, majoritariamente, determinada pelos resíduos do pastejo (pasto + esterco), que foram maiores nas áreas com pastejo leve e nas áreas sem pastejo.
Integrated crop-livestock systems are lately being increasingly used in the country, and there is a great utilization potential in brazilian subtropic region, by integrating catlle production in a large area covered by winter pastures, preceeding summer crops, mostly soybean and corn. The animal, in such systems, is considered the catalizing agent, while the soil is the compartment that captures all the modifications imposed by animal and pasture management This research investigated a soybean-cattle system in a pasture mixture (ryegrass + black oat), managed at different plant heights (10, 20, 30 and 40 cm) and no grazed areas. The experiment was established in May, 2001, in São Miguel das Missões county, Rio Grande do Sul state – Brazil, in a clayey Hapludox, under no-tillage system. The impacts of the integrated system management in total and particulated fractions of carbon and nitrogen were studied nine years after the experiment started. Nutrient (carbon. nitrogen, phosphorus, potassium, calcium and magnesium) cycling was also studied in two soybean-livestock cycles (2009/11), by plant and animal residue decomposition in litter bags. Moderately and light (20 and 30 and 40 cm plant height, respectively) pasture pressure resulted in similar increase of total and particulated carbon and nitrogen stocks and contents, as found in no-grazed area. Carbon managements indexes (CMI), as compared with the reference areas, indicated high degradation of organic matter quality under the most instensive grazing intensity (10 cm of pasture height). Nutrient cycling was higher in moderately grazing (20 and 30 cm pastures height), for pasture and cattle residues. Soybean residue decomposition was not affected by pasture and cattle management; however soybean leaves were more readily decomposed, and in this way, fastly release nutrients, as compared with stem decomposition. The amount of released nutrients in a soybean-cattle cycle is high as compared with plants (pasture and soybean) requirement for high yields and mostly determined by cattle and pasture residues that were higher under light and no grazing intensities, due to higher residue production.

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Rozak, Andes. "Vers une meilleure estimation des stocks de carbone dans les forêts exploitées à Diptérocarpées de Bornéo." Thesis, Paris, AgroParisTech, 2018. http://www.theses.fr/2018AGPT0008/document.

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Les forêts tropicales constituent le principal réservoir de biodiversité et de carbone (C). Cependant, la plupart des forêts tropicales, en particulier les forêts de Bornéo en Asie du Sud-Est, subissent une pression intense et sont menacées par des activités anthropiques telles que l'exploitation forestière, l'industrie minière l’agriculture et la conversion en plantations industrielles. En 2010, la superficie des forêts de production de Bornéo était de 26,8 millions d’ha (environ 36% de la superficie totale de l’île, dont 18 millions ha (environ 24%) déjà exploités. Par conséquent, les forêts de production occupent donc une place importante à Bornéo et jouent un rôle essentiel dans la compensation des biens fournis et la maintenance des services écosystémiques, tels que la conservation du C et de la biodiversité.L’exploitation sélective réduit la biomasse aérienne et souterraine par l’élimination de quelques grands arbres, et augmente les stocks de bois mort par des dommages collatéraux. En créant des trouées dans la canopée, le microclimat dans les sous-étages et au sol change localement et accélèrent la décomposition de la litière et de la matière organique. L'importance des dégâts, de l'ouverture de la canopée et de la rapidité du rétablissement du C s'est avéré principalement liée à l'intensité de l'exploitation forestière. Cependant, les évaluations empiriques de l'effet à long terme de l'intensité de l'exploitation forestière sur l'équilibre du C dans les forêts de production restent rares.La présente thèse se concentre principalement sur l'évaluation de l'effet à long terme de l'intensité de l'exploitation forestière sur la séquestration de carbone dans une forêt à Diptérocarpées de Nord Bornéo (District de Malinau, Kalimantan Nord) exploitée en 1999/2000. Cinq principaux réservoirs de C, à savoir le C aérien dans les arbres vivants (AGC), le C souterrain dans les arbres vivants (BGC), le bois mort, la litière et le C organique du sol (SOC) ont été estimés le long d’un gradient d'intensité d'exploitation (0-57% de la biomasse perdue).Nos résultats ont montré que les stocks totaux de C, 16 ans après l'exploitation, variaient de 218 à 554 Mg C ha-1 avec une moyenne de 314 Mg C ha-1. Une différence de 95 Mg C ha-1 a été observée entre une faible intensité d'exploitation forestière (<2,1% de la biomasse initiale perdue) et une intensité d'exploitation élevée (>19%). La plus grande partie du C (environ 77%) était présente dans les arbres vivants, suivie par les stocks du sol (15%), les stocks de bois mort (6%) et une fraction mineure des stocks de litière (1%). L'empreinte de l'intensité de l'exploitation forestière était encore détectable 16 ans après l'exploitation et a été le principal facteur expliquant la réduction des AGC>20, BGC>20, du bois mort et des stocks de C et une augmentation du bois mort. L'intensité de l'exploitation expliquait à elle seule 61%, 63%, 38% et 48% des variations des AGC>20, BGC>20, du bois mort et des stocks de C totaux, respectivement. L'intensité de l'abattage a également réduit considérablement les stocks de SOC dans la couche supérieure de 30 cm. Pour l'ensemble des stocks de SOC (0-100 cm), l'influence de l'intensité de l'exploitation était encore perceptible, en conjonction avec d'autres variables.Nos résultats quantifient l'effet à long terme de l'exploitation forestière sur les stocks de C forestier, en particulier sur les AGC et les bois morts. L'intensité élevée de l'exploitation forestière (réduction de 50% de la biomasse initiale) a réduit les stocks totaux de C de 27%. La récupération de l'AGC était plus faible dans les parcelles d'intensité d'exploitation forestière élevée, ce qui suggère une résilience plus faible de la forêt à l'exploitation forestière. Par conséquent, une intensité d'exploitation forestière inférieure à 20%, devrait être envisagé afin de limiter l'effet à long terme sur les AGC et le bois mort
Tropical forests are a major reservoir of biodiversity and carbon (C), playing a pivotal role in global ecosystem function and climate regulation. However, most of the tropical forests, especially Bornean forests in Southeast Asia, are under intense pressure and threatened by anthropogenic activities such as logging, mining industry, agriculture and conversion to industrial plantation. In 2010, the area of production forests in Borneo was 26.8 million ha (approx. 36% of the total land area of Borneo) including 18 million ha (approx. 24%) of logged forests. Production forests are thus emerging as a dominant land-use, playing a crucial role in trading-off provision of goods and maintenance of ecosystem services, such as C and biodiversity retention.Selective logging is known to reduce both above- and below-ground biomass through the removal of a few large trees, while increasing deadwood stocks through collateral damages. By creating large gaps in the canopy, microclimates in the understory and on the forest floor change locally speeding up the decomposition of litter and organic matter. The extent of incidental damages, canopy openness, as well as the speed of C recovery, was shown to be primarily related to logging intensity. However, empirical evaluations of the long-term effect of logging intensity on C balance in production forests remain rare.The present thesis aims to assess the long-term effect of logging intensity on C sequestration in a north Bornean Dipterocarp forests (Malinau District, North Kalimantan) logged in 1999/2000. Five main C pools, namely above-ground (AGC) and below-ground (BGC) carbon in living trees, deadwood, litter, and soil organic carbon (SOC) were estimated along a logging intensity gradient (ranging from 0 to 57% of initial biomass removed).Our result showed that total C stocks 16 years after logging, ranged from 218-554 Mg C ha-1 with an average of 314 Mg C ha-1. A difference of 95 Mg C ha-1 was found between low logging intensity (<2.1% of initial biomass lost) and high logging intensity (>19%). Most C (approx. 77%) was found in living trees, followed by soil (15%), deadwood (6%), and a minor fraction in litter (1%). The imprint of logging intensity was still detectable 16 years after logging, and logging intensity thus was the main driver explaining the reduction of AGC>20, BGC>20, deadwood, and total C stocks and an increase in deadwood. Solely, logging intensity explained 61%, 63%, 38%, and 48% of variations of AGC>20, BGC>20, deadwood, and total C stocks, respectively. Logging intensity also significantly reduced SOC stocks in the upper 30 cm layer. For total SOC stocks (0-100 cm), the negative influence of logging intensity was still perceptible, being significant in conjunction with other variables.Our results quantify the long-term effect of logging on forest C stocks, especially on AGC and deadwood. High logging intensity (50% reduction of initial biomass) reduced total C stocks by 27%. AGC recovery was lower in high logging intensity plots, suggesting lowered forest resilience to logging. Our study showed that maintaining logging intensity, below 20% of the initial biomass, limit the long-term effect of logging on AGC and deadwood stocks

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Santos, Josiane Bürkner dos. "Alterações no estoque e taxa de sequestro de carbono em um Latossoto vermelho submetido a sistemas de manejo." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2006. http://tede2.uepg.br/jspui/handle/prefix/2193.

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The objective of this study was to quantify the changes of the total carbon (C) and total nitrogen (N) stock, and the variation of the C pool’s in monthly soil samples, and the C balance and C sequestration rates provoked by the soil tillage systems. The soil samples were accomplished in a long term experiment implanted in 1988, in the experimental station of Fundação ABC located in Ponta Grossa city, Center-South area of the Paraná State. The soil tillage systems were comprised: a) Conventional Tillage (CT); b) Minimum Tillage (MT); c) No-tillage with chisel plow (NTCP) each three years; and d) No-tillage – Continuous (NTC). Soil samples for each treatments were obtained by digging 3 profiles of 20-cm x 50-cm (surface area) x 50-cm deep for each replicate, and collected from three depths (0,0- to 2.5- cm, 2.5- to 5-cm, 5- to 10-cm). In the samples collected in October of 2003, May of 2004 and November of 2004, the total organic carbon (TOC) and the total nitrogen in all of the depths was measured. The particle size fractionation was accomplished, separating the soil in fractions in the size of 2000 - 210 Wm, 210 - 53 Wm and <53 Wm. In all these fractions TOC was determined. The treatments had significant effects on TOC and TN contents and pools. The total C and N stock in NTC was superior to the other systems demonstrating larger maintenance of C in the soil. The larger concentration of C was observed in the 210 to 53 Wm particle size fraction in the NTC. In the 2000 - 210 Wm fraction of the 0,0-2,5 cm layer were observed larger changes in the C stock due to the management systems in the samples at all long year. The greatest change was accomplished to CT. In NTP, the stock of C was larger in all soil samples, indicating that the maintenance of the cultural residues in the associated surface protection of the aggregates allows larger accumulation of C. Although the C stock in the particle size fraction <53 Wm not to present significant differences among the management systems, and was observed the C migration of the coarse fractions (210-53 and 2000-210 Wm) to the recalcitrant particle size fraction, indicating a continuous C flow. The C balance model adjusted for the local conditions revealed that the oxidation rate acted by K2 is inferior to the simulations accomplished by other authors, demonstrating the importance of the local conditions. With this model, the minimum amount of crop residues to maintain NTC system in steady-state was 8,05 Mg ha-1 year-1 while in the PC treatment it won't be possible to reach the balance with the amount of crop residues placed in this long term experiment, being a deficient system.
RESUMO Este estudo teve por objetivo quantificar as alterações provocadas pela adoção de sistemas de manejo do solo sobre o estoque total de carbono (C) e nitrogênio (N), a variação do estoque do C nas épocas de coleta, o balanço de C e as taxas de seqüestro de C. As coletas do solo foram realizadas em um experimento de longa duração, implantado em 1988, na estação experimental da Fundação ABC em Ponta Grossa, Meso Região Centro-Oriental do Estado do Paraná. Os sistemas de manejo do solo foram avaliados: a) Preparo convencional (PC), Preparo mínimo (PM), plantio direto escarificado (PDE) e plantio direto permanente (PDP). As amostras foram coletadas em 12 épocas com intervalos mensais e nas profundidades de 0,0-2,5; 2,5-5,0 e 5,0-10 cm de profundidade. As amostras deformadas foram coletadas em mini-trincheiras nas camadas de 0,0-2,5 e 2,5-5,0 cm e na camada de 5,0- 10,0 cm com o auxílio do trado. Nas amostras coletadas em outubro de 2003, maio de 2004 e novembro de 2004 foi determinado o carbono orgânico total (COT) e o nitrogênio total (NT) em todas as profundidades amostradas. Nas amostras coletadas mensalmente foi realizado o fracionamento granulométrico da matéria orgânica, separando o solo em frações no tamanho 2000 – 210 Wm, 210 – 53 Wm e < 53 Wm. Em todas estas frações foi determinado o COT. O estoque total de C e N no PDP foi superior aos demais sistemas de manejo demonstrando maior manutenção do C no solo. O estoque de C nas frações granulométricas apresentaram diferenças significativas entre as camadas amostradas, observando-se maior concentração de C na fração 210 a 53 Wm do PDP. Na fração 2000 – 210 Wm da camada de 0,0-2,5 cm observaram-se maior alteração no estoque de C devido aos sistemas de manejo durante as épocas de coleta, sendo a maior amplitude de variação atribuída ao PC. No PDP, o estoque de C foi maior em todas as épocas de coleta indicando que a manutenção dos resíduos culturais na superfície associada à proteção dos agregados permite maior acúmulo de C. Embora o estoque de C na fração < 53 Wm não apresentar diferenças significativas entre os sistemas de manejo, observou-se uma migração do C das frações mais grosseiras (210-53 e 2000-210 Wm) para esta fração mais recalcitrante, indicando um fluxo contínuo de C. O modelo de balanço de C proposto por Henin e Dupuis (1945) e ajustado para as condições locais revelou que a taxa de oxidação representada pelo K2 é inferior às simulações realizadas por outros autores, demonstrando a importância das condições locais. Com este modelo, a quantidade mínima de resíduos culturais para manter sistema PDP em equilíbrio foi de 8,05 Mg ha-1 ano-1 enquanto no PC não será possível atingir o equilíbrio com a quantidade de resíduos culturais aportada, sendo um sistema deficitário.

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MUNIZ, Luciano Cavalcante. "Integração lavoura pecuária: efeitos no solo, na forragem, modelagem e simulação econômica." Universidade Federal de Goiás, 2010. http://repositorio.bc.ufg.br/tede/handle/tde/1089.

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When approaching the crop-livestock integration (CLI) theme, the present thesis had as one of its main objectives to evaluate the alterations in the soil-plantanimal- environment components exercised by the crop and pasture rotation dynamics in crop and livestock integration system. Two adjacent areas, one representing the natural environment (original cerrado vegetation) and other the degraded pastures served as reference ( control ) to the inferences performed. The experiment was performed at a 92 ha area, divided into six paddocks of approximately 15 ha, where the annual crops and pastures rotation was made. The soil samplings were collected at the 0-10, 10-20, 20-30, 30-40 and 40-50 cm layers. There was an increase in the carbon contents of the microbial biomass, in the microbial quotient and in the organic matter on the soil and reduction in the metabolic quotient at the pastures chronological sequence environments, at the crop-livestock integration system, in comparison with the degraded pasture. The different pastures stages within the crop-livestock integration system stocked the average of 17,67 Mg ha-1 carbon more than the degraded pasture up to a 50 cm depth. The Cerrado contained the most carbon stock and the degraded pasture the least among all the environments studied. There was a significant decrease in the phosphor and potassium contents in relation to the pasture age increase and an increase in the calcium and magnesium contents. Micronutrients contents among the treatments evaluated presented values above the demand for capim- Marandu. The capim-Marandu samplings were performed in five different seasons of the year (winter, beginning and end of spring, summer and autumn). Quantitative and qualitative alterations at the forage were observed during the experimental period. Changes on the structural components green leaf, green stem and dead material, as well as on DM (Dry Matter), GP (Gross Protein), TDN (Total Digestive Nutrients) and FND (Fiber in Neutral Detergent) contents, among others, characterized the forage on the different periods. The qualitative variations among the forages are of high magnitude, being outlined the significant drop on GP (Gross Protein) and TDN (Total Digestive Nutrients) contents according to the pasture maturity development. All pastures chronological sequence treatments, after 2,5 years of crop, resulted in favorable evaluations, having P1 treatment as the best investment option with NPV (Net Present Value) equals to R$144,34 followed by P2 treatment with R$112,61 and P3 with R$58,54, indicating to be a favorable Project. There is indication on the present work that the biggest loss in relation to the obtained economic advantages happens already from the second year after the pastures establishment. Such results may constitute important implications at CLI systems planning. Carbon bonus at pasture based animal production system may be a financial incentive for the producer to join the pastures rotation with annual crops. Nevertheless it is necessary that studies are performed to quantify emissions of gases responsible for greenhouse in order to verify whether the result represents a bonus or an environmental onus to the producer.
A presente tese, ao abordar o tema integração lavoura-pecuária (ILP), teve como um de seus principais objetivos avaliar as alterações nos componente solo-planta-animal-ambiente exercidas pela dinâmica de rotação de culturas e pastagens em sistema de integração lavoura e pecuária. Duas áreas adjacentes, uma representativa do meio ambiente natural (vegetação de cerrado original ) e outra de pastagens degradadas, serviram de referência ( controle ) às inferências realizadas. O experimento foi realizado numa área de 92 ha, dividida em seis piquetes de aproximadamente 15 ha, onde foi feita a rotação de culturas anuais e pastagens. As amostras de solo foram coletadas nas camadas 0-10, 10-20, 20-30, 30-40 e 40-50 cm. Houve aumento nos teores de carbono da biomassa microbiana, no quociente microbiano e na matéria orgânica no solo e redução no quociente metabólico nos ambientes da cronossequência das pastagens, no sistema integração lavoura-pecuária, em comparação com a pastagem degradada. As diferentes fases das pastagens dentro do sistema de integração lavoura-pecuária estocaram, em média, 17,67 Mg ha-1 mais carbono que a pastagem degradada até a profundidade de 50 cm. O Cerrado conteve o maior, e a pastagem degradada o menor estoque de carbono entre todos os ambientes estudados. Houve um decréscimo significativo nos teores de fósforo e potássio com o aumento da idade da pastagem e aumento nos teores de cálcio e magnésio. Os teores dos micronutrientes entre os tratamentos avaliados apresentaram valores acima da exigência para o capim-Marandu. As amostras de capim-Marandu foram realizadas em cinco épocas do ano (inverno, início e final da primavera, verão e outono). Alterações quantitativas e qualitativas na forragem foram observadas durante o período experimental. Mudanças nos componentes estruturais folha verde, colmo verde e material morto, bem como nos teores de matéria seca (MS), proteína bruta (PB), nutrientes disponíveis totais (NDT) e fibra em detergente neutro (FDN), entre outros, caracterizaram a forragem nos diferentes períodos. As variações qualitativas entre as forrageiras são de alta magnitude, destacando-se a queda significativa nos teores de PB e NDT, com o avanço da maturidade da pastagem. Todos os tratamentos da cronossequência das pastagens, após 2,5 anos de lavoura, resultaram em avaliações favoráveis, sendo o tratamento P1 a melhor opção de investimento, com valor presente líquido (VPL) igual a R$ 144,34, seguido pelo tratamento P2 com R$ 112,61 e P3 com R$ 58,54, indicando tratar-se de projeto favorável. Há indicação no presente trabalho que a maior perda em relação às vantagens econômicas obtidas ocorre já a partir do segundo ano após o estabelecimento das pastagens, podendo constituir implicações importantes no planejamento de sistemas de ILP. O bônus de carbono no sistema de produção animal a pasto pode ser um incentivo financeiro para o produtor aderir à rotação de pastagens com culturas anuais. Porém é preciso que sejam realizados estudos que quantifiquem as emissões de gases responsáveis pelo efeito estufa, para verificar se o balanço representa um bônus ou um ônus ambiental para o produtor.

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Briedis, Clever. "Compartimentos da matéria orgânica do solo, agregação, mecanismos de proteção e sequestro de carbono influenciados pela calagem superficial em sistema plantio direto." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2010. http://tede2.uepg.br/jspui/handle/prefix/2202.

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Liming is the most often practice used to neutralize soil acidity, and also promotes chemical changes that can alter the soil organic matter (SOM) pools and the mechanisms of flocculation, formation and stabilization of macro-and microaggregates. The objective of this study was to evaluate carbon sequestration, in the whole and in the aggregates samples, and the changes in the SOM pools affected by liming in a long-term no-tillage. The experiment was conducted in an Oxisol, located in Ponta Grossa, PR. The experimental design was a randomized complete block, arranged as split plot with three replications. The main plot consisted of dolomite lime applied on the soil surface at a 0 or 6 Mg ha-1 in 1993, and 0 or 3 Mg ha-1 in 2000 in plots previously with and without lime, and the treatments was assigned as: 0+0, 6+0, 0+3 and 6+3 Mg ha-1. The subplots were represented by sampling depth and consist of 0-2.5, 2.5-5, 5-10 and 10-20 cm layer. The soil samples were taken in September 2008 and the total organic carbon (TOC) was analyzed in the whole sample, in the aggregates and in the particulate organic carbon (POC) and in the fraction associated with minerals carbon (OCAM). Aggregates of 8-19 mm, in the 0-2.5 cm layer were analyzed by using scan microscope spectrometer X-ray (EDS) for elemental analysis of carbon (C) and calcium (Ca). Liming promoted accumulation of TOC mainly in the layer 0-2.5 cm. The TOC stocks at 0-20 cm were 49.9, 52.9, 52.7 and 57.5 Mg ha-1 for 0+0, 6+0, 0+3, 6 +3 treatments, respectively. Stocks in the SOM fractions were also increased with liming. The increase in POC stock was close relationship (R2 = 0.98, P = 0.011) with the C accumulated input through crop residue, which was higher in plots that were limed. A positive correlation was found between TOC and C extracted in hot water (CHW), total polysaccharides (TP) and labile (LP). Correlations also showed that TOC had a closer relationship with POC than with OCAM, suggesting a greater influence on the labile fraction of TOC increase with liming. In aggregate, the effect of liming in TOC accumulation was mainly in 0-2.5 cm depth. The treatments with liming showed high mean weight diameter (MWD), which provided a large stock of TOC in the 8-19 mm aggregate size. A higest proportion of large aggregates with liming was closely correlated with the TOC content of whole sample. The highest liming dosis resulted in both COP and in OCAM, in the largest class of aggregates. The proportion of POC average of the treatments in relation to OCAM, this class of aggregates, has decreased in depth, and were 18, 13, 10 and 8% at depths of 0-2.5, 2.5-5, 50-10 and 10-20, respectively. Elemental analysis of C and Ca showed a positive correlation of those elements contained in a section of clay from the center of 8-19 mm aggregates. The results suggest that application of lime in soil with clay fraction dominated by kaolinite, brings benefits to structuring and promotes an increase of C in the whole sample and in aggregates.
A calagem é a prática mais utilizada para neutralizar a acidez do solo, porém promove também modificações químicas capazes de alterar os compartimentos da matéria orgânica do solo (MOS) e mecanismos de floculação, formação e estabilização de macro e microagregados. O objetivo desse trabalho foi avaliar o seqüestro de carbono, na amostra integral e nos agregados, e as alterações nos compartimentos da MOS afetados por calagem superficial em sistema plantio direto de longa duração. O experimento foi conduzido em um Latossolo Vermelho textura média, no município de Ponta Grossa, PR. O delineamento experimental foi o de blocos completos ao acaso em parcelas subdivididas, com três repetições. As parcelas consistiram da aplicação de calcário dolomítico na superfície do solo na dose de 0 ou 6 Mg ha-1 em 1993, e dose de 0 ou 3 Mg ha-1 em 2000 nas parcelas previamente com e sem calcário, compondo os tratamentos: 0+0; 6+0; 0+3 e 6+3 Mg ha-1. As subparcelas foram constituídas pelas profundidades de coleta, sendo realizadas em 0-2,5, 2,5-5, 5-10 e 10-20 cm de profundidade. As coletas de solo foram realizadas em setembro de 2008 e analisados os conteúdos de carbono orgânico total (COT) na amostra total, nos agregados e nas frações particulada (COP) e associada aos minerais (COAM) da matéria orgânica do solo (MOS). Agregados de 8-19 mm, da camada 0-2,5 cm, foram analisados através do uso de espectrômetro de dispersão de raios X (EDS) para a análise elementar de carbono (C) e cálcio (Ca). A calagem promoveu acúmulo de COT, principalmente na camada 0-2,5 cm. Os estoques de COT na camada de 0-20 cm foram 49,9, 52,9, 52,7 e 57,5 Mg ha-1 para os tratamentos 0+0, 6+0, 0+3 e 6+3, respectivamente. Os estoques nas frações da MOS também foram aumentados com a calagem. O aumento no estoque de COP foi estreitamente relacionado (R2=0,98; P=0,011) com a adição acumulada de C via resíduo cultural, a qual foi mais elevada nas parcelas que receberam calagem. Houve correlação positiva entre COT e carbono em água quente (CAQ), polissacarídeos totais (PT) e lábeis (PL). Correlações também demonstraram que o COT teve relação mais estreita com o COP do que com COAM, sugerindo maior influência da fração lábil no aumento de COT com a calagem. Nos agregados, a calagem proporcionou acúmulo de COT principalmente na profundidade de 0-2,5 cm. A calagem aumentou o diâmetro médio ponderado (DMP), proporcionando grande estoque de COT na classe de agregado 8-19 mm. A elevada proporção de agregados grandes nos tratamentos com calagem foi estreitamente correlacionado com o conteúdo de COT da amostra integral. A maior dose de calcário proporcionou aumento no estoque de COT tanto em COP quanto em COAM, visto principalmente na maior classe de agregados. A proporção de COP em relação ao COAM, na média dos tratamentos, nessa classe de agregados, diminuiu em profundidade, ficando em torno de 18, 13, 10 e 8 % nas profundidades de 0-2,5, 2,5-5, 5-10 e 10-20, respectivamente. Análise elementar de C e Ca demonstraram correlação positiva dos dois elementos contidos em uma secção da fração argila do centro de agregados de 8-19 mm. A aplicação de calcário, em solo dominado na fração argila por caulinita, traz benefícios à estruturação e promove aumento de C na amostra integral e nos agregados.

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