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1
Alexander, Peter Mark William. "Modelling the UK perennial energy crop market." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9645.
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Biomass produced from perennial energy crops, Miscanthus and willow or poplar grown as short-rotation coppice, is expected to contribute to UK renewable energy targets and reduce the carbon intensity of energy production. The UK Government has had incentives in place, targeting farmers and power plant investors to develop this market, but growth has been slower than anticipated. Market expansion requires farmers to select to grow these crops, and the construction of facilities, such as biomass power plants, to consume them. Farmer behaviour and preferences, including risk-aversion, are believed to be important to crop selection decisions. Existing research estimating the total potential resource has either only simplistically considered the farmer decision-making and opportunity costs, or has not considered spatial variability. No previous work has modelled the contingent interaction of farmers’ decisions with the construction of biomass facilities. This thesis provides an improved understanding of the behaviour of the perennial energy crop market in the UK, by addressing these limitations, to understand the spatial and temporal dynamics of energy crop adoption. It attempts to determine the factors that govern the rate and level of adoption, to quantify the greenhouse gas abatement potential, and to assess the cost effectiveness of policy mechanisms. A farm-scale mathematical programming model was implemented to represent the crop selection of a risk-averse farmer. This was applied using spatially specific data to produce maps and cost curves economic supply, for the UK. To represent the contingent interaction of supply and demand within the market, an agent-based model was then developed. The results indicate that perennial energy crop supply may be substantially lower than previously predicted, due to the time lags caused by the spatial diffusion of farmer adoption. The model shows time lags of 20 years, which is supported empirically by the analogue of oilseed rape adoption. Results from integrating a greenhouse gas emissions balance shows that directly supporting farmers, via establishment grants, can increase both the carbon equivalent emissions abatement potential and cost effectiveness of policy measure. Results also show a minimum cost of carbon abatement is produced from scenarios with an intermediate level of electricity generation subsidy. This suggests that there is a level of support for electricity generated from energy crops that reduces emissions in the most cost effective manner.
2
Zhang, Xiaohua 1964. "Price expectations in perennial crop supply models." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/291531.
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In the analysis of investment and production decisions for perennial crops, expectations play a critical role. This thesis studied three hypotheses about price expectations and reviewed five supply response models for perennial crops. An empirical model for the apple industry was developed to test alternative representations of expected prices. The naive and adaptive expectation model performed well with national data, whereas moving averages of price and the adaptive expectations model performed better with Washington data. To improve estimates of supply response for perennial crops, better data are needed to describe new plantings, removals, the age distribution of trees, production costs, and climatic conditions. Rapid technological change in the U.S. apple industry may cause producers to revise the way they form expected prices, encouraging them to use more historical information and paying more attention to projections of future demand. Rational expectations perspectives may become increasingly relevant.
3
Huggett, David Alan John. "Potential insect pests of the biomass crop Miscanthus." Thesis, Imperial College London, 1997. http://hdl.handle.net/10044/1/7180.
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Koivisto, Jason M. "Semi-leafless peas : a cover crop for establishing lucerne or red clover." Thesis, Coventry University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246331.
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Xue, Yao. "Accessing Chilling Conditions For Perennial Fruit Crop Production in Kentucky." TopSCHOLAR®, 2015. http://digitalcommons.wku.edu/theses/1486.
Full textAbstract:
Temperate Region fruit and nut trees, and many other perennial plants, require cool winter temperatures (chilling hours) to ensure leaf and flower bud production in the following season. Temperate Regions are characterized by variable winter and spring temperatures. Failure of meeting sufficient chilling requirement results in deformed fruits, unequal maturation, and other plant deformities, thereby reducing quality and yields. Chilling requirements are expressed as number of accumulated hours within a range of approximately 32º to 45ºF or 0º to 7.2ºC. These requirements are specific for level of temperature, length of temperature period, and species and cultivar of plants. Information on chilling hour production by the diverse Kentucky environments and chilling requirements of its plants is limited. Global warming is reducing the occurrence and length of chilling conditions, thereby negatively impacting perennial fruit production (IPCC, 2014). There is increasing interest in fruit crops by the state’s producers and consumers. The Kentucky Mesonet Weather System provides temperature data, which can readily be converted to chilling units. Also, commercial nurseries are beginning to publish chilling requirement data for their fruit stocks. The present study included data collected over A 5-years period at 33 Mesonet sites. The average number of chilling hours overall years and sites was 1544, year means ranged from 1427 to 1842, sites means ranged from 1422 to 1682. Chilling hour production exceeded chilling requirements of fruit and nut crops commonly grown in Kentucky.
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Shortall, Orla. "Rethinking bioenergy from an agricultural perspective : ethical issues raised by perennial energy crop and crop residue production for energy in the UK and Denmark." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/28756/.
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The aim of this project is to explore the social and ethical dimensions of the agricultural production of perennial energy crop and crop residues for energy. Biomass – any living or recently living matter – is being promoted in industrialised countries as part of the transition from fossil fuels to an economy based on renewable energy. Various challenges face the use of bioenergy however. One particularly controversial and high profile example has been the use of food crop biofuels in transport which are seen to conflict with food production and to cause significant environmental damage. Suggested ways around these controversies is the production of perennial energy crops such as grasses and trees and crop residues such as straw, which are seen to require fewer inputs and less prime land. Some have analysed the controversies raised by biofuels in terms of controversies around industrial agriculture more broadly: biofuels are perceived to be large scale, monocultural, environmentally damaging and pushed by agri-business and energy interests. This project asks what type of agriculture system perennial energy crops and crop residues are seen as developing within, if at all. This was considered worth exploring because the type of system will have a large bearing on how they are received in future. To this end a theoretical framework of different paradigms of agriculture ranging from industrial agriculture at one end to alternative agriculture at the other was developed and applied to the data. Interviews with key stakeholders and analysis of key documents in the UK and Denmark were carried out to address the question of how perennial energy crops and crop residues are seen as overcoming previous controversies raised by food crop biofuels, in terms of their place in agricultural systems. The thesis argues that stakeholder’s visions of perennial energy crops and crop residues can be understood in terms of four models of agriculture: two industrial and two alternative. These are called “industrialism lite” that involves producing perennial energy crops on marginal land; life sciences integrated agriculture including the biorefinery strategy; multifunctional perennial energy crop production on environmentally marginal land; and ecologically integrated multipurpose biomass production through agroforestry production. There is also an argument which cuts across the paradigms and maintains that regardless of the type of agricultural system used very little or no biomass should be produced for the energy sector because of the scale of resources it requires and the scale of society’s energy use. These positions can be summarised as three different ways to overcome challenges raised by food crop biofuels: further industrialise agriculture; de-industrialise agriculture; and de-industrialise agriculture and reduce society’s energy use, though biomass could still only be used to a very limited extent, if at all, in energy production.
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McKenzie, Scott. "An aboveground-belowground herbivore interaction in a woody perennial crop and its response to elevated atmospheric CO2." Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/73333/.
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Interactions between above ground and root-feeding herbivores can be influenced by changes in plant traits, such as tissue chemistry and morphology. Environmental heterogeneity and perturbations also affect these plant-mediated interactions. Climate change is a multi-faceted phenomenon; increases in atmospheric carbon dioxide (CO2) concentrations lead to increased global mean temperature and an associated higher frequency of extreme weather events. These factors can potentially perturb ecosystem function by altering both plant–herbivore and herbivore–herbivore interactions. A detailed understanding of whether above–belowground interactions are affected by climate change remains lacking. In an attempt to fill knowledge gaps in this understudied area of ecology, this thesis investigates, through a series of glasshouse experiments, the effects of elevated CO2 and other aspects of climate change, such as altered phenology, on the interspecific interaction between the aboveground large raspberry aphid (Amphorophora idaei) and the root feeding larvae of the vine weevil (Otiorhynchus sulcatus), mediated by the shared raspberry (Rubus idaeus) host-plant. Under ambient climate conditions, reciprocal feeding facilitation was observed to occur between aphids and vine weevil larvae feeding on raspberry, with the presence of one increasing the abundance of the other herbivore, and vice versa. This occurred regardless of plant cultivar and order of herbivore arrival on the plant. It is likely that this facilitative relationship is driven by over-compensatory plant growth in response to herbivory. Although tougher, adult vine weevils show a feeding preference for leaves grown in elevated CO2. Herbivory may be more influential than CO2 in determining plant–herbivore interaction outcomes. Aphids affect plant intraspecific competition to a greater extent than elevated CO2 by altering plant biomass of both infested and non-infested plants. In conclusion, this particular plant–herbivore system would seem to be relatively robust in the face of possible future CO2 concentration scenarios.
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CHIMENTO, CARLO. "ASSESSMENT OF THE CARBON SEQUESTRATION POTENTIAL IN SOIL AND IN BELOWGROUND BIOMASS OF SIX PERENNIAL BIOMASS CROP." Doctoral thesis, Università Cattolica del Sacro Cuore, 2015. http://hdl.handle.net/10280/6072.
Full textAbstract:
L'obiettivo della ricerca è stato quello di identificare la coltura bioenergetica con il maggior potenziale di sequestro del carbonio (C); sono state considerate tre colture perenni arboree (pioppo, robinia e salice) e tre colture erbacee perenni (canna comune , miscanto e panico ) al sesto anno dal loro impianto e coltivate nello stesso ambiente.
In primo luogo sono state misurate le variazioni dei tassi del C organico del suolo (COS) per il primo 1 m, mentre per i primi 30 cm di suolo è stato stimato il grado di stabilita del COS valutando sette frazioni di COS che presentano differenti gradi di stabilizzazione; in secondo luogo, sono stati caratterizzati gli apparati radicali delle sei specie per la stessa profondità di suolo, per valutare dove le specie accumulano la biomassa radicale lungo il profilo di suolo. I risultati confermano che l’impianto di colture bioenergetiche perenni su superfici precedentemente dedite a colture annuali gestite convenzionalmente rappresenta una opzione valida per sequestrare C nel soulo. Tuttavia, è stata osservata una diversa capacità di sequestro di C tra specie arboree ed erbacee: le specie arboree hanno dimostrato aumentre il contenuto di COS nel primo strato di suolo ( 0-10 cm di suolo), ma la loro capacità di allocare biomassa radicale negli strati profondi del suolo è limitata; mentre, la specie erbacee allocano un’alta quantità di biomassa radicale negli strati profondi del suolo, ma solo il panico ed il miscanto hanno aumentato il contenuto di C nel primo strato di suolo.The objective of the present research was to identify the bioenergy crop with the greatest carbon sequestration potential among three perennial woody crops (poplar, black locust and willow) and three perennial herbaceous crops (giant reed, miscanthus and switchgrass) at the sixth year from plantation and in the same location. First of all the SOC stock variations for the first 1 m soil depth and the quantification of seven soil C fractions related to SOC stabilization level of the first 30 cm of soil were assessed; secondly, a characterization of the root system and the traits which affect the carbon allocation in soil were considered. The results confirm that the establishment of perennial bioenergy crops in previous arable fields can be a suitable option to sequester carbon (C) belowground. However, a different C sequestration capacity was observed between woody and herbaceous crops: woody species showed the greatest SOC sequestration potential in the first soil layer (0-10 cm of soil) but their ability to allocate root biomass in the deeper soil layers was limited; while, the herbaceous species allocated a high amount of root biomass in the deeper soil layers, but only switchgrass and miscanthus sequester C in the first soil layer.
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CHIMENTO, CARLO. "ASSESSMENT OF THE CARBON SEQUESTRATION POTENTIAL IN SOIL AND IN BELOWGROUND BIOMASS OF SIX PERENNIAL BIOMASS CROP." Doctoral thesis, Università Cattolica del Sacro Cuore, 2015. http://hdl.handle.net/10280/6072.
Full textAbstract:
L'obiettivo della ricerca è stato quello di identificare la coltura bioenergetica con il maggior potenziale di sequestro del carbonio (C); sono state considerate tre colture perenni arboree (pioppo, robinia e salice) e tre colture erbacee perenni (canna comune , miscanto e panico ) al sesto anno dal loro impianto e coltivate nello stesso ambiente.
In primo luogo sono state misurate le variazioni dei tassi del C organico del suolo (COS) per il primo 1 m, mentre per i primi 30 cm di suolo è stato stimato il grado di stabilita del COS valutando sette frazioni di COS che presentano differenti gradi di stabilizzazione; in secondo luogo, sono stati caratterizzati gli apparati radicali delle sei specie per la stessa profondità di suolo, per valutare dove le specie accumulano la biomassa radicale lungo il profilo di suolo. I risultati confermano che l’impianto di colture bioenergetiche perenni su superfici precedentemente dedite a colture annuali gestite convenzionalmente rappresenta una opzione valida per sequestrare C nel soulo. Tuttavia, è stata osservata una diversa capacità di sequestro di C tra specie arboree ed erbacee: le specie arboree hanno dimostrato aumentre il contenuto di COS nel primo strato di suolo ( 0-10 cm di suolo), ma la loro capacità di allocare biomassa radicale negli strati profondi del suolo è limitata; mentre, la specie erbacee allocano un’alta quantità di biomassa radicale negli strati profondi del suolo, ma solo il panico ed il miscanto hanno aumentato il contenuto di C nel primo strato di suolo.The objective of the present research was to identify the bioenergy crop with the greatest carbon sequestration potential among three perennial woody crops (poplar, black locust and willow) and three perennial herbaceous crops (giant reed, miscanthus and switchgrass) at the sixth year from plantation and in the same location. First of all the SOC stock variations for the first 1 m soil depth and the quantification of seven soil C fractions related to SOC stabilization level of the first 30 cm of soil were assessed; secondly, a characterization of the root system and the traits which affect the carbon allocation in soil were considered. The results confirm that the establishment of perennial bioenergy crops in previous arable fields can be a suitable option to sequester carbon (C) belowground. However, a different C sequestration capacity was observed between woody and herbaceous crops: woody species showed the greatest SOC sequestration potential in the first soil layer (0-10 cm of soil) but their ability to allocate root biomass in the deeper soil layers was limited; while, the herbaceous species allocated a high amount of root biomass in the deeper soil layers, but only switchgrass and miscanthus sequester C in the first soil layer.
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Weeks, James Michael Jr. "Perennial Grass Based Crop Rotations in Virginia: Effects on Soil Quality, Disease Incidence, and Cotton and Peanut Growth." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/35394.
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In 2003 eight peanut and cotton crop rotations were established in southeastern Virginia,
4 of which included 2 or 3 years of tall fescue or orchardgrass grown as high-value hay crops.
Each crop rotation was evaluated for changes in soil quality indicators including soil carbon and
nitrogen, water stable soil aggregates, plant available water content, bulk density, cone index
values, and soil moisture. Cotton and peanut growth and yield were also observed to evaluate
changes in crop growth associated with differences in soil quality. Soilborne plant pathogens including root-knot nematode, stubby root nematode, ring nematode, stunt nematode, and
Cylindrocladium parasiticum microsclerotia were measured in the spring and fall of each year to
determine differences associated with crop rotations. Water stable soil aggregates in 2007 were higher in rotations with 3 years of either perennial grass. Soil moisture tended to be the highest at depths 30 - 60 cm in the 3-year tall fescue rotation in August and September 2007. Cotton in 2006 and peanut in 2007 had higher growth and yield where the annual crop directly followed a perennial grass. Root-knot nematode tended to decrease in all rotations over time. Stubby root nematode populations tended to increase in rotations with either duration of orchardgrass. Including perennial grasses in cotton and peanut rotations has the potential to increase growth and yield as demonstrated in this research.Master of Science
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Wagner, Moritz [Verfasser], and Iris [Akademischer Betreuer] Lewandowski. "Methodological approaches for assessing the environmental performance of perennial crop-based value chains / Moritz Wagner ; Betreuer: Iris Lewandowski." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2018. http://d-nb.info/1149721790/34.
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Pugliese, Jennie Y. "Above- and Belowground Response to Managing Kernza (Thinopyrum intermedium) as a Dual-Use Crop for Forage and Grain." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1494000853982965.
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Doole, Graeme John. "Value of perennial pasture phases in dryland agricultural systems of the eastern-central wheat belt of Western Australia." University of Western Australia. School of Agricultural and Resource Economics, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0213.
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Over the past thirty years, price relativities and technological development have motivated an increase in the area of land allocated to cropping, as opposed to pasture production, throughout the central wheat belt of Western Australia. Nevertheless, reducing the proportion of pasture in these rotations has challenged the future productivity of farming systems in this area. First, the frequent application of selective herbicides for weed control in extended cropping rotations has promoted the development of herbicide resistance in a number of major agricultural weeds. Second, the primary use of annual plants has promoted the development of soil salinisation by allowing a significant proportion of rainfall to recharge saline water tables. The inclusion of perennial pasture phases between extended periods of cropping may mitigate or delay these constraints to production through (a) allowing the use of costeffective forms of non-selective weed control, and (b) through creating a buffer of dry soil that absorbs leakage occurring beneath subsequent crops. This study consequently explores the value of including perennial pasture phases in dryland agricultural systems in the eastern-central wheat belt of Western Australia, accounting for benefits related to herbicide resistance and water table management. A novel computational algorithm for the solution of multiple-phase optimal control problems is developed and used to conduct a conceptual analysis of the value of lucerne (Medicago sativa L.) pasture for managing annual ryegrass (Lolium rigidum Gaudin), the primary weed in wheat belt cropping systems. The competitiveness and fecundity of annual ryegrass provide strong economic incentives to maintain a low weed population, irrespective of herbicide-resistance status. Consequently, the ineffectiveness of selective herbicides primarily reduces the profitability of cropping by motivating the adoption of more costly non-selective forms of weed control. The inclusion of lucerne in land-use rotations is only optimal in the presence of severe herbicide resistance given (a) the low efficiency of alternative weed-management practices available during the pasture phase, relative to selective-herbicide application; (b) the significant cost of establishing this perennial pasture; and (c) the high relative profitability of cereal production in the absence of resistance. The value of lucerne, relative to annual pastures, for weed management is explored in greater detail through the use of compressed annealing to optimise a sophisticated simulation model. The profitability of candidate rotations is also manipulated to account for the long-term production losses accruing to the recharge of saline groundwaters that occurs beneath them. Sequences incorporating lucerne are only more profitable than those that include annual pasture at the standard set of parameter values if (a) annual ryegrass is resistant to all selective herbicides, (b) the water table is so shallow (approximately less than 3.5 m deep) that frequent rotation with perennials is required to avert soil salinisation, or (c) sheep production is highly profitable. The value of perennial pasture is sufficient under these circumstances to overcome its high establishment cost. Consistent with intuition, these benefits are reinforced by lower discount rates and higher rates of leakage occurring beneath annual-based systems. Formulation of an effective communication strategy to report these results to producers is justified given the complexity involved in determining the true magnitude of these intertemporal benefits through alternative means, such as field trials.
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Salas, Andrea. "Effects of Host-plant Density on Herbivores and Their Parasitoids: A Field Experiment with a Native Perennial Legume." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2583.
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Senna mexicana chapmanii (Fabaceae: Caesalpinoideae), an attractive and threatened species native to pine rocklands of southern Florida, is consumed by folivorous caterpillars of Sulfur butterflies (Lepidoptera: Pieridae). Caterpillars may be deterred or eaten by predators, but also very important are parasitoids, both flies and wasps. This study investigated the effects of plant density on Sulfur caterpillar numbers and rates of parasitization.
Senna mexicana chapmanii plantations were established at agricultural and urban areas; both sites are adjacent to protected pine rockland areas. Sulfur butterfly immature stages were collected and reared to glean information regarding number of herbivores and rates of parasitization. Continuing this weekly monitoring protocol over the course of a year provided data to determine that higher plant density has an effect on levels of parisitization and is correlated with the number of herbivores. Elucidating these patterns has important implications understanding the factors that regulate interactions in this plant/herbivore/parasitoid system.
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Meiss, Helmut. "Diversifying crop rotations with temporary grasslands : potentials for weed mangement and farmland biodiversity." Phd thesis, Université de Bourgogne, 2010. http://tel.archives-ouvertes.fr/tel-00575607.
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Crop rotation may be used to prevent the continuous selection of particular weed species adapted to one crop type. This might be useful for weed management, economy in herbicide applications and promoting biodiversity. Common simple crop sequences might be diversified by introducing perennial forage crops. Impacts of such perennial crops on weeds were studied with four approaches : 1) Large-scale weed surveys in 632 fields in western France showed that weed species composition differed most strongly between perennial alfalfa crops and annual crops. Comparisons of fields before, during and after perennial alfalfa suggested that community composition varies in a cyclic way during such crop rotations. Several weed species problematic in annual crops were suppressed during and after perennial crops, but the appearance of other species led to equal or even higher plant diversities. 2) A 3-year field experiment with contrasting crop management options allowed an investigation of the underlying mechanisms for this: The absence of soil tillage reduced weed emergence but increased the survival of established plants. The permanent vegetation cover and frequent hay cuttings reduced weed growth, plant survival and seed production. 3) Greenhouse experiments testing the regrowth ability of individual plants after cutting showed strong differences between species and functional groups. An two-factorial experiment suggested that the negative impacts of cutting and competition on weed growth were mainly additive. 4) Special measurements of weed seed predation in the field experiment showed positive correlations with vegetation cover, indicating that this ecosystem service may be particularly fostered by perennial crops. Consistent preferences of seed predators for certain weed species indicates that seed predation may be another cause of the observed weed community shifts.
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Palik, Destiny J. "The Invasive Potential of Perennial Biofuel Crops." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503309520467401.
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Zatta, Alessandro <1976>. "Soil organic carbon dynamics under perennial energy crops." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5921/1/Zatta_Alessandro_SOC_dynamics_perennial_energy_crops.pdf.
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The European renewable energy directive 2009/28/EC (E.C. 2009) provides a legislative framework for reducing GHG emissions by 20%, while achieving a 20% share of energy from renewable sources by 2020. Perennial energy crops could significantly contribute to limit GHG emissions through replacing equivalent fossil fuels and by sequestering a considerable amount of carbon into the soil through the large amounts of belowground biomass produced. The objective of this study is to evaluate the effects of land use change that perennial energy crops have on croplands (switchgrass) and marginal grasslands (miscanthus). For that purpose above and belowground biomass, SOC variation and Net Ecosystem Exchange were evaluated after five years of growth. At aboveground level both crops produced high biomass under cropland conditions as well as under marginal soils. At belowground level they also produced large amounts of biomass, but no significant influences on SOC in the upper layer (0-30 cm) were found. This is probably because of the "priming effect" that caused fast carbon substitution. In switchgrass only it was found a significant SOC increase in deeper layers (30-60 cm), while in the whole soil profile (0-60 cm) SOC increased from 42 to 51 ha-1. However, the short experimental periods (for both switchgrass and miscanthus), in which land use change was evaluated, do not permit to determine the real capacity of perennial energy crops to accumulate SOC. In conclusion the large amounts of belowground biomass enhanced the SOC dynamic through the priming effect resulting in increased SOC in cropland but not in marginal grassland.
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Zatta, Alessandro <1976>. "Soil organic carbon dynamics under perennial energy crops." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5921/.
Full textAbstract:
The European renewable energy directive 2009/28/EC (E.C. 2009) provides a legislative framework for reducing GHG emissions by 20%, while achieving a 20% share of energy from renewable sources by 2020. Perennial energy crops could significantly contribute to limit GHG emissions through replacing equivalent fossil fuels and by sequestering a considerable amount of carbon into the soil through the large amounts of belowground biomass produced. The objective of this study is to evaluate the effects of land use change that perennial energy crops have on croplands (switchgrass) and marginal grasslands (miscanthus). For that purpose above and belowground biomass, SOC variation and Net Ecosystem Exchange were evaluated after five years of growth. At aboveground level both crops produced high biomass under cropland conditions as well as under marginal soils. At belowground level they also produced large amounts of biomass, but no significant influences on SOC in the upper layer (0-30 cm) were found. This is probably because of the "priming effect" that caused fast carbon substitution. In switchgrass only it was found a significant SOC increase in deeper layers (30-60 cm), while in the whole soil profile (0-60 cm) SOC increased from 42 to 51 ha-1. However, the short experimental periods (for both switchgrass and miscanthus), in which land use change was evaluated, do not permit to determine the real capacity of perennial energy crops to accumulate SOC. In conclusion the large amounts of belowground biomass enhanced the SOC dynamic through the priming effect resulting in increased SOC in cropland but not in marginal grassland.
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Bergkvist, Göran. "Perennial clovers and ryegrasses as understorey crops in cereals /." Uppsala : Dept. of Ecology and Crop Production Science, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a414.pdf.
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Sorrenti, Giovambattista <1974>. "Biochar in perennial crops: nutritional, agronomical and environmental implications." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7129/1/Sorrenti_Giovambattista_tesi.pdf.
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Biochar is the solid C-rich matrix obtained by pyrolysis of biomasses, currently promoted as a soil amendment with the aim to offset anthropogenic C emissions, while ameliorating soil properties and growth conditions. Benefits from biochar seem promising, although scientific understandings are beginning to be explored. In this project, I performed a suite of experiments in controlled and in field conditions with the aims to investigate the effect of biochar on: a) the interaction with minerals; b) Fe nutrition in kiwifruit; c) soil leaching, soil fertility, soil CO2 emissions partitioning, soil bacterial profile and key gene expression of soil nitrification-involved bacteria; d) plant growth, nutritional status, yield, fruit quality and e) its physical-chemical changes as affected by long-term environmental exposure. Biochar released K, P and Mg but retained Fe, Mn, Cu and Zn on its surface which in turn hindered Fe nutrition of kiwifruit trees. A redox reaction on the biochar surface exposed to a Fe source was elucidated. Biochar reduced the amount of leached NH4+-N but increased that of Hg, K, P, Mo, Se and Sn. Furthermore, biochar synergistically interacted with compost increasing soil field capacity, fertility, leaching of DOC, TDN and RSOC, suggesting a priming effect. However, in field conditions, biochar did not affect yield, nutritional status and fruit quality. Actinomadura flavalba, Saccharomonospora viridis, Thermosporomyces composti and Enterobacter spp. were peculiar of the soil amended with biochar plus compost which exhibited the highest band richness and promoted gene expression levels of Nitrosomonas spp., Nitrobacter spp. and enzymatic-related activity. Environmental exposure reduced C, K, pH and water infiltration of biochar which instead resulted in a higher O, Si, N, Na, Al, Ca, Mn and Fe at%. Oxidation occurred on the aged biochar surface, it decreased progressively with depth and induced the development of O-containing functional groups, up to 75nm depth.
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Sorrenti, Giovambattista <1974>. "Biochar in perennial crops: nutritional, agronomical and environmental implications." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7129/.
Full textAbstract:
Biochar is the solid C-rich matrix obtained by pyrolysis of biomasses, currently promoted as a soil amendment with the aim to offset anthropogenic C emissions, while ameliorating soil properties and growth conditions. Benefits from biochar seem promising, although scientific understandings are beginning to be explored. In this project, I performed a suite of experiments in controlled and in field conditions with the aims to investigate the effect of biochar on: a) the interaction with minerals; b) Fe nutrition in kiwifruit; c) soil leaching, soil fertility, soil CO2 emissions partitioning, soil bacterial profile and key gene expression of soil nitrification-involved bacteria; d) plant growth, nutritional status, yield, fruit quality and e) its physical-chemical changes as affected by long-term environmental exposure. Biochar released K, P and Mg but retained Fe, Mn, Cu and Zn on its surface which in turn hindered Fe nutrition of kiwifruit trees. A redox reaction on the biochar surface exposed to a Fe source was elucidated. Biochar reduced the amount of leached NH4+-N but increased that of Hg, K, P, Mo, Se and Sn. Furthermore, biochar synergistically interacted with compost increasing soil field capacity, fertility, leaching of DOC, TDN and RSOC, suggesting a priming effect. However, in field conditions, biochar did not affect yield, nutritional status and fruit quality. Actinomadura flavalba, Saccharomonospora viridis, Thermosporomyces composti and Enterobacter spp. were peculiar of the soil amended with biochar plus compost which exhibited the highest band richness and promoted gene expression levels of Nitrosomonas spp., Nitrobacter spp. and enzymatic-related activity. Environmental exposure reduced C, K, pH and water infiltration of biochar which instead resulted in a higher O, Si, N, Na, Al, Ca, Mn and Fe at%. Oxidation occurred on the aged biochar surface, it decreased progressively with depth and induced the development of O-containing functional groups, up to 75nm depth.
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Zuhair, Segu M. M. "Harvesting behavior of perennial cash crops: a decision theoretic study." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/76322.
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This study analyzed the harvesting behavior of perennial cash-crop growers in Sri Lanka. These growers face two alternatives with respect to harvesting; premature and mature harvesting.
The objectives of the study were: to determine the reasons for premature harvesting, to explain this behavior with socio-economic factors as explanatory variables, and to describe the behavior with decision theory.
The first objective was achieved by surveying a sample of 240 farmers. Fear of theft and immediate money needs were the reasons why most farmers harvested their crop at a premature stage.
A logit probability model was used to explain this behavior. Education of the farmer, ratio of lowland to total land operated by the farmer, and the total family income were significantly related to harvesting behavior.
Expected utility theory, expected profit maximization, and a lexicographic safety-first model were used to predict farmer behavior. The expected utility approach used the exponential utility function, the quadratic utility function, and the cubic utility function. The lexicographic safety-first model minimized the probability of regret as the first objective and maximized the expected income as the second objective, in that order.
The expected utility model with the exponential utility function made the largest number of correct predictions followed by the expected profit maximizing model. The conclusions of this study, while providing more evidence of the poor predictive ability of the expected profit maximizing model, further supports the usefulness of expected utility theory in describing and predicting farmer behavior. A majority of the studies on farmer behavior have concentrated on resource allocation. This study has demonstrated that even harvesting behavior can be explained by expected utility theory.
There was no consistency in the way the utility functions ranked the two harvesting alternatives; for certain farmers the ranking of one function reversed the ranking of other functions. This study has, thus, demonstrated the influence of utility functional forms on the ranking of prospects. The results were sensitive to changes in the discount rate and the results of the safety-first model were sensitive to changes in the expected income.Ph. D.
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Pizzani, Rodrigo. "Produção e qualidade de forragens e atributos de um Argissolo vermelho." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/5478.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorIn Brazil, most soils used in the livestock presents some fertility limitations. One of the alternatives to improve the soils quality is the introduction of perennial species, including grassy and associated legumes and correction of the soil that it will hold the cultures forage crop. There s a lack of Information and researches on soil quality improvement using perennial forages. Therefore, the objective of this work was to evaluate different systems of forage cultures constituted by Pennisetum americanum, Arachis pintoi and Stylosanthes guianensis associated with Cynodon dactylon and both isolated species, with and without mineral fertilizer, and evaluations of the attributes of a Ultisols. In both treatments, Cynodon dactylon received 100 kg of nitrogen during a year. The crops of forage samples were accomplished at every 28 days, making botanical separation and drying the same. After the weighting to calculate the dry matter per area (ha) the samples were crushed for analyses of fiber of neutral detergent (FDN), fiber of acid detergent (FDA), rude protein (PB), calcium (Ca), magnesium (Mg), phosphorus (P) and potassium (K). The samples collecting were taken during January, March, April and October of 2007. The best results of nutritional values were found in the legumes and in the consortium, being with inferior quality the grassy ones. The dry matter present a great variation among the cuts and the forage systems. After the winter the Stylosanthes portions were lost, due to the frosts that happened during this period. This confirms that it not has an adaptation on our conditions of winter. After a year of implantation of the experiment was collected soil to analysis: density of the soil (DS), microporosity (Mip) and macroporosity (Map) porosity and total porosity of the soil (PT) and size of aggregates. In the chemical part, were analyzed total nitrogen (NT), total organic carbon (COT) and phosphorus (P) and potassium (K). DS presented variation between the treatments and the appraised layers, since 1,40 to 1,62 Mg m-3. In Mip and PT didn't present significant differences between the treatments and layers, but Map presented significant differences. In the aggregate size there was significant differences, and the geometric medium diameter (DMG) it varied from 1,41 to 3,21 mm. In the soil chemical attributes both maintained similarities, in other words, larger concentration in the first layer (0 to 5 cm). But some treatments standing out in larger concentration in the first layer, however maintain similarities in the deep layers, unless the potassium (K), that has a distribution more constantly in the evaluated layers.
No Brasil, a maioria dos solos utilizados para pecuária apresenta algumas limitações de fertilidade. Uma das alternativas para melhorar as condições desses solos é a introdução de espécies perenes, incluindo gramíneas e leguminosas consorciadas e correção do solo que comportará as culturas forrageiras. Informações e pesquisas sobre melhorias de solos com uso de espécies forrageiras perenes são escassas. Nesse sentido, o objetivo deste trabalho foi avaliar diferentes sistemas de culturas forrageiras constituídas de milheto, amendoim forrageiro e estilosantes consorciados com tifton 85 e ambas as espécies isoladas, com e sem adubação mineral, e avaliações dos atributos de um Argissolo vermelho. Em ambas as parcelas adubadas e não adubadas, o tifton 85 recebeu 100 kg de nitrogênio ano-1. As colheitas de amostras de forragem eram realizadas a cada 28 dias, realizando-se separação botânica e secagem da mesma. Feita a pesagem para calcular matéria seca (MS) por área (ha) realizava-se a moagem das amostras para análises de fibra de detergente neutro (FDN), fibra de detergente ácido (FDA), proteína bruta (PB), cálcio (Ca), magnésio (Mg), fósforo (P) e potássio (K). Realizaram-se coletas nos meses de janeiro, março, abril e outubro de 2007. Os melhores resultados de valores de PB, FDA e FDN, foram encontrados nas leguminosas e no consórcio, ficando com qualidade inferior o tifton 85 + 100 kg ha-1 de N. Quanto à produção de MS, variou muito entre os cortes e os sistemas forrageiros. Após o inverno as parcelas de estilosantes foram perdidas, devido às geadas que ocorreram no período de inverno. Isso confirma que o mesmo não tolera frio e não se adapta a nossas condições de inverno. Após um ano de implantação do experimento realizou-se coletas para análise dos atributos do solo, sendo: densidade do solo (DS), micro (Mip) e macro (Map) porosidade e porosidade total do solo (PT) e tamanho de agregados. Na parte química, analisou-se nitrogênio total (NT), carbono orgânico total (COT) e teores de fósforo (P) e potássio (K). A DS apresentou variação entre os tratamentos e as camadas avaliadas, desde 1,40 a 1,62 Mg m-3. Na Mip e PT não apresentou diferenças significativas entre os tratamentos e camadas, mas o Map apresentou diferenças significativas. Nos tamanhos dos agregados houve diferenças significativas, sendo que o diâmetro médio geométrico (DMG) variou de 1,41 a 3,21 mm. Nos atributos químicos do solo, como NT, COT, P e K ambos mantiveram semelhanças, ou seja, maior concentração na primeira camada (0 a 5 cm). Mas alguns tratamentos se destacaram em maior concentração na primeira camada, mantendo semelhanças nas camadas mais profundas, exceto o K que teve uma distribuição mais uniforme nas camadas avaliadas.
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Propheter, Jonathan L. "Direct comparison of biomass yields of annual and perennial biofuel crops." Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1393.
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Morrison, Eilidh Christina. "Methyl halide and biogenic volatile organic compound fluxes from perennial bioenergy crops and annual arable crops." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8279.
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The depletion of fossil fuel resources, pollution concerns and the challenge of energy security are driving the search for renewable energy sources. The use of lignocellulosic plant biomass as an energy source is increasing in the United Kingdom and worldwide. In the UK, up to 0.35MHa (6% of total arable land) may be planted with perennial bioenergy crops by 2020 in order to meet renewable energy and CO2 reduction targets. Several plant species that produce high biomass from low inputs have been identified. The most promising for the UK climate are the genus Miscanthus, a perennial rhizomatous grass which can grow up to 3.5m in a year, and short rotation coppice (SRC) willow (Salix spp.), plantations of which can remain viable for up to 30 years. Although bioenergy crops are perceived as “carbon neutral”, changes in land use can have a wider impact on atmospheric composition than through CO2 alone. This study compares vegetation fluxes of methyl halides (CH3Br and CH3Cl) and biogenic volatile organic compounds (BVOCs) from perennial bioenergy crops and annual arable crops at three sites in the UK. Methyl halides are the most abundant natural vectors of bromine and chlorine into the stratosphere and play an important role in stratospheric ozone destruction. BVOCs affect atmospheric oxidising capacity and are a major precursor to the formation of ozone and secondary organic aerosols in the troposphere. Although terrestrial vegetation is an important source of these trace gases there are very few previous measurements of these reactive gases from bioenergy crops. This study describes measurements conducted at two SRC willow sites in Scotland, and one site in England planted with adjacent perennial bioenergy crops and annual arable crops, to quantify and characterise natural methyl halide and BVOC fluxes from vegetation. Measurements were conducted with branch chambers, using static enclosure techniques to measure methyl halide fluxes and dynamic enclosures to measure BVOCs such as isoprene and -pinene. Fluxes were calculated from the concentration difference between background/inlet samples and after enclosure/outlet samples. Methyl halide concentrations were determined by sampling gas from static enclosures followed by analysis using an oxygen-doped GC-ECD with a custom-built pre-concentration unit. Samples for BVOC analysis were collected onto adsorbent tubes and a thermal desorption GC-MS was used to determine BVOC concentrations. Potentially influential environmental variables such as photosynthetically active radiation (PAR), total solar radiation, air temperature, soil temperature, internal chamber temperature and soil moisture were recorded in parallel to the enclosures to determine their potential relationships to fluxes. Long-term environmental data was also available from on-site or nearby weather stations. Long-term measurements were carried out for 2 1 2 years at a site in Lincolnshire, England where adjacent fields are planted with Miscanthus, SRC willow and annual arable crops (wheat and oilseed rape crop rotation). Vegetation measurements were made almost every month throughout the period, with more intensive measurements such as full diurnal cycle carried out during the summer. Ten sampling points are sampled in each field and semi-diurnal measurements are taken regularly. Long-term measurements were also carried out at two sites in Scotland planted with SRC willow, one in Arnot, Perth & Kinross which was sampled for a year and one in East Grange, Fife which was sampled for half a year. Up to 30 sampling points were employed in Arnot and another 10 in East Grange. The bioenergy crops and wheat emitted low fluxes of methyl halides in comparison to the oilseed rape. Mean annual net fluxes of CH3Br and CH3Cl from Miscanthus were 1.8 ng g (dry weight)-1 h-1 and 11 ng g-1 h-1, respectively. At the three willow sites, mean annual net fluxes of CH3Br and CH3Cl ranged between 0.6 - 1.7 ng g-1 h-1, and 1.7 - 12 ng g-1 h-1, respectively. Negligible fluxes of methyl halides were measured from wheat but oilseed rape was found to emit large fluxes of methyl halides with mean annual net fluxes of CH3Br and CH3Cl of 20 ng g-1 h-1and 144 ng g-1 h-1, respectively. The largest BVOC fluxes were measured from SRC willow at the Brattleby site, with high mean annual net fluxes of isoprene (77 μ g g-1 h-1), α -pinene (46 g μg-1 h-1), β -pinene (5.5 μ g g-1 h-1), limonene (3.7 μ g g-1 h-1) and δ -3-carene (11 μ g g-1 h-1). However, mean annual net BVOC fluxes measured at Arnot and East Grange were much lower. High fluxes of - pinene were measured from Miscanthus in 2010 (giving a mean annual net flux of 65 μ g g-1 h-1) but no other significant BVOC fluxes were distinguished. Negligible fluxes of isoprene were measured from wheat but fluxes of monoterpenes were high with mean annual net fluxes of 65 μ g g-1 h-1 and 25 μg g-1 h-1 for α -pinene and limonene, respectively. No significant fluxes of BVOCs were measured from the oilseed rape. All fluxes demonstrated a strong seasonal trend with higher emissions during the summer growing season and low to zero emissions over winter. The high spatial variability was captured by sampling from many points in each field. Some diurnal measurements exhibited a clear pattern of higher emissions during the day and low to zero emissions at night. Some positive correlations between fluxes and environmental variables such as PAR and air temperature were observed. An experiment carried out on willow cuttings in the greenhouse found no clear increase or decrease in fluxes of BVOCs in response to N fertiliser treatment, instead fluxes were found to vary significantly with some of the observed environmental variables. UK estimates were derived by extrapolating measured fluxes using the current respective land cover areas for Miscanthus and SRC willow. Estimated UK annual fluxes of CH3Br and CH3Cl from Miscanthus were 0.01Mgy-1 and 0.05Mgy-1, respectively and from SRC willow were 0.06Mgy-1 and 0.4Mgy-1, respectively, accounting for a very small percentage of total global annual turnover of CH3Br and CH3Cl. Estimated UK annual fluxes of the BVOCs isoprene and α -pinene from Miscanthus were 0.01Mgy-1 and 0.4Mgy-1, respectively and from SRC willow were 3Mgy-1 and 1Mgy-1, respectively. Future planting of SRC willow to meet the UKs energy needs could lead to a potential annual isoprene flux of 150 MgMgy-1.
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Nocentini, Andrea <1986>. "Measured and Modeled C Flows after Land Use Change to Perennial Bioenergy Crops." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amsdottorato.unibo.it/7801/1/Measured%20and%20modeled%20C%20flows%20after%20land%20use%20change%20to%20perennial%20bioenergy%20crops_Andrea%20Nocentini.pdf.
Full textAbstract:
In the first part of this Thesis the general concepts and state of art of the research subjects are introduced, then focusing on the impact of the land use change to perennial bioenergy crops on agricultural systems’ carbon stocks. Then, the specific objectives of the research that has been carried out are stated.
In the second part, the detailed methods and results of the four experiments performed are described one by one. All four papers constitute original research. The first and second papers originate from direct field measurements investigating the carbon flows subsequent to the establishment of perennial grasses for bioenergy on, respectively, a fertile agricultural land and a marginal land resembling, since it had been cultivated with poplar for the previous thirty years, the conditions of a biomass supply district. The third and fourth papers originate from model simulations investigating the potential of perennial biomass crops to produce energy and second-generation biofuels at the regional scale and their impact on soil carbon stocks and, more generally, on greenhouse gases emissions. Finally, by converging the findings of all the four experiments, general conclusions are drawn, also underlying future perspectives, current gaps and further research needed in order to fill these gaps.
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Linares, B. Jose Clemente. "Integrative use of perennial and annual cover crops for weed management in organic citrus." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0015616.
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Muraki, Tomohiro. "Effects of alternative grass species on grazing preference of sheep for white clover." Diss., Lincoln University, 2008. http://hdl.handle.net/10182/1095.
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Despite the importance of a high white clover (Trifolium repens) content in temperate pastoral systems in terms of livestock performance and nitrogen fixation, the proportion of white clover in grass-clover pastures is often low (<20%). This thesis examined in two experiments whether the white clover content of pastures could be improved by sowing white clover with alternative grass species to diploid perennial ryegrass (Lolium perenne L.). In a pasture experiment, DM production, pasture composition and morphology of grass-clover mixtures was measured over the establishment year (January 2007 to January 2008) where white clover was sown in fine mixtures with diploid perennial ryegrass, tetraploid perennial ryegrass, timothy (Phleum pratense L.) and cocksfoot (Dactylis glomerata L.). Pastures were irrigated and rotationally grazed with on-off grazing with Coopworth ewe hoggets. Total annual DM production of pasture was more than 20% higher in tetraploid (12521 kg DM ha⁻¹) and diploid (11733 kg DM ha⁻¹) perennial ryegrass than timothy (9751 kg DM ha⁻¹) and cocksfoot (9654 kg DM ha⁻¹). However, timothy (5936 kg DM ha⁻¹) and cocksfoot (5311 kg DM ha⁻¹) had more than four times higher white clover annual DM production than tetraploid (1310 kg DM ha⁻¹) and diploid (818 kg DM ha⁻¹) ryegrass. Pasture growth rate at the first three harvests in autumn was significantly greater in tetraploid and diploid ryegrass than timothy and cocksfoot. Timothy and cocksfoot had a higher proportion of white clover than tetraploid and diploid perennial ryegrass throughout the entire year. This was due to more and larger white clover plants in timothy and cocksfoot plots. In a grazing preference experiment, the partial preference of sheep for white clover offered in combination with the same grass species as in the pasture experiment was measured in five grazing tests in May, September, October, November and December 2007. Pastures were sown in January 2007. Paired plots (grass and clover both 4.2 m x 10 m) were grazed by three Coopworth ewe hoggets between 9am and 5pm, and preference was recorded by decline in pasture mass and visual scan sampling for grazing time. Grazing preference for clover was generally low throughout these tests (e.g. average apparent DM intake from clover = 47%; average grazing time from clover = 44%). Several explanations are proposed for this low preference including a high N content and intake rate of the grass relative to the clover. No significant differences were found among the grass treatments in total grass grazing time, total clover grazing time, ruminating time, the proportion of grazing time on clover, selective coefficient for clover and DM intake percentage from clover at any date. There was no significant change in overall sward surface height (SSH) decline among grass treatments throughout all the tests except December 2007 when the overall SSH decline for cocksfoot was significantly lower than the other species. The study indicated that the rapid growth rate of perennial ryegrass in the early phase of pasture establishment, rather than differences in partial preference, was the key factor limiting white clover content in the mixed swards relative to cocksfoot and timothy pastures. It is concluded that high clover-containing pastures capable of delivering high per head performance can be established through the use of slow establishing pasture species such as timothy and cocksfoot.
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Beckort, Richard. "Evaluation of Three Coverings for the Overwintering of Container Grown Herbaceous Perennials in Kentucky." TopSCHOLAR®, 1987. https://digitalcommons.wku.edu/theses/2153.
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The purpose of this study was to evaluate three coverings for overwintering twelve varieties of container grown herbaceous perennials under Kentucky conditions. The twelve perennial varieties were started from seed in the spring and had been moved to one gallon containers by fall. In the first week of December, three blocks of containers were covered with one of the following: one layer of 4 mil, milky copolymer; one layer of quarter inch microfoam and one layer of milky copolymer; a sandwich of two layers of milky copolymer with 6 inches of wheat straw between them; the remaining block was left uncovered as a check.
The perennials were uncovered in the spring, observed, and evaluated. The single layer of copolymer and the microfoam and copolymer treatments had the most new growth. The growth under the copolymer and straw sandwich method was elongated and white. Only three containers in the uncovered treatment showed signs of regrowth.
The microfoam and copolymer and the single layer of milky copolymer proved to be the best coverings for the over - wintering container grown herbaceous perennials in Kentucky.
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Pardon, Lénaïc. "Modelling of the nitrogen budget of oil palm plantations to help reduce losses to the environment. Case study in Sumatra, Indonesia." Thesis, Paris, Institut agronomique, vétérinaire et forestier de France, 2017. http://www.theses.fr/2017IAVF0018/document.
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L’humanité fait face aux défis urgents de réduire l’impact environnemental de l’agriculture, de changer les régimes alimentaires et d’accroître la production alimentaire. Le palmier à huile est une plante pérenne tropicale emblématique de ces défis. Alors que sa culture peut être à l’origine d’impacts environnementaux, le palmier à huile peut produire, en conditions optimales, 7 à 10 fois plus d’huile alimentaire que les cultures oléagineuses annuelles. Dans ce contexte, améliorer la durabilité de la production d’huile de palme est crucial, tant pour réduire les impacts environnementaux négatifs que pour garantir la sécurité alimentaire. L’application de fertilisants azotés (N) a été identifiée comme une source majeure d’impacts environnementaux dus à la culture du palmier. Des analyses de cycle de vie de l’huile de palme ont été réalisées pour quantifier les impacts et identifier des améliorations de pratiques agricoles. Cependant, les seuls modèles d’émissions disponibles pour estimer les pertes de N dans l’environnement sont généralement valides pour les cultures annuelles et en climat tempéré. L’utilisation de tels modèles dans l’analyse de cycle de vie peut mener à des résultats très incertains ou à une faible sensibilité aux pratiques. L’objectif global de ce travail de recherche était d’aider à l’identification de pratiques pour réduire les pertes de N dans l’environnement. Le cœur du travail était le développement d’un modèle estimant toutes les pertes de N dans les plantations, tout en étant sensible aux pratiques. L’étude s’est concentrée sur les flux de N dans les plantations de palmiers sur sols minéraux. Nous avons réalisé quatre étapes pour mener à bien cette recherche. Premièrement, nous avons mené une revue de littérature de tout le savoir existant concernant les flux et pertes de N dans les plantations. Deuxièmement, nous avons comparé 11 modèles existants, pouvant être utilisés pour prédire les pertes de N dans les plantations. Troisièmement, nous avons réalisé une analyse de sensibilité de Morris approfondie du modèle mécaniste APSIM-Oil palm. Quatrièmement, nous avons construit IN-Palm, un indicateur agri-environnemental pour les pertes de N dans les plantations. Nous avons utilisé la méthode INDIGO® et l’approche de modélisation par arbres de décisions flous pour développer IN-Palm, et nous avons validé cet indicateur en utilisant des mesures de lixiviation de N d’une plantation à Sumatra, Indonésie. Notre revue de littérature et notre comparaison de modèles ont montré que les particularités du palmier à huile peuvent affecter significativement les dynamiques et pertes de N. Nous avons identifié des manques de recherche et des incertitudes sur les pertes de N, leurs déterminants et la modélisation des particularités du palmier. Nous avons identifié les déterminants des pertes de N et du rendement dans le modèle mécaniste APSIM-Oil palm. Nous avons développé IN-Palm, qui utilise 21 variables d’entré facilement accessibles pour estimer chaque voie de perte de N. Les prédictions de lixiviation de N par IN-Palm étaient acceptables, et IN-Palm s’est montré efficace pour tester des changements de pratiques agricoles. Cette recherche constitue une synthèse exhaustive des connaissances et modèles disponibles pour les flux et pertes de N dans les plantations. L’un des principaux résultats est un nouvel indicateur agri-environnemental, IN-Palm, sensible aux pratiques et conditions locales, de même qu’utilisable en tant que modèle d’émission dans des approches holistiques. Cet indicateur peut être une base utile pour de futures recherches sur l’utilisation d’indicateurs agri-environnementaux pour réduire l’incertitude des analyses cycle de vie, et pour de futures adaptations à d’autres plantes pérennes tropicalesHumanity faces the challenges of urgently decreasing the environmental impact of agriculture, shifting diets and increasing food production. Oil palm is a tropical perennial crop emblematic of these challenges. While its cultivation can be associated with environmental impacts, oil palm can produce 3 to 7 t of edible oil ha-1 in optimal conditions, which is 7 to 10 fold higher than in annual oil crops. In this context, improving palm oil production sustainability is crucial for both reducing negative environmental impacts and ensuring food security. Application of synthetic nitrogen (N) fertilisers was identified as a major source of environmental impacts associated with the cultivation of oil palm. Life cycle assessments of palm oil have already been performed to help quantify impacts and identify potential improvements of management practices. However, the only available emission models to estimate N losses to environment are generally valid for annual crops and temperate climate conditions. The use of such general models in life cycle assessment may lead to very uncertain results or to low sensitivity of assessments to management practices. The overall objective of this research work was to help identify management practices to reduce N losses in the environment. The core of the work was hence to develop a model that estimates all N losses in oil palm plantations, while being sensitive to management practices. The study focused on N fluxes in industrial oil palm plantations on mineral soils. We performed four steps in order to complete the objectives of this research work. First, we conducted a literature review of all the existing knowledge about N fluxes and losses in plantations. Second, we compared 11 existing models that may be used to predict N losses in plantations. Third, we performed an in-depth Morris’s sensitivity analysis of one of the models, the APSIM-Oil palm process-based model. Fourth, we used all the information identified in the previous chapters, together with expert knowledge, to build IN-Palm, an agri-environmental indicator for N losses in oil palm plantations. We used the INDIGO® method and the fuzzy decision tree modelling approach to develop IN-Palm, and we validated this indicator using a field dataset of N leaching from a plantation in Sumatra, Indonesia. Our literature review and model comparison showed that oil palm peculiarities may impact significantly N dynamics and losses. We identified research gaps and uncertainties about N losses, their drivers and the modelling of oil palm peculiarities. We identified the main drivers of N losses and yield in the APSIM-Oil palm processbased model. We built IN-Palm, which uses 21 readily available input variables to estimate each N loss pathway. IN-Palm predictions of N leaching were acceptable, and IN-Palm has shown efficient to help testing management changes. This research constitutes a comprehensive synthesis of the available knowledge and models for N fluxes and losses in oil palm plantations. One of the main results is a novel agri-environmental indicator, IN-Palm, operationally-oriented, sensitive to local practices and environmental conditions, as well as potentially useable as an emission model for holistic approaches such as life cycle assessment. The INDIGO® method and fuzzy decision tree modelling approach were shown to be very well adapted for building agri-environmental indicators in contexts of knowledge scarcity. This indicator can be a useful base for further research about using agrienvironmental indicators to reduce uncertainty in life cycle assessment, and for future adaptations for other tropical perennial crops
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Gunathilaka, R. P. Dayani. "Economic impacts of climate change on perennial plantation tree crops: the case of tea production in Sri Lanka." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/377583.
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Agriculture is one sector of the economy which is highly vulnerable to climate change because of the natural relationship between environment, particularly temperature and water availability, and agricultural productivity. Changing climate is increasingly affecting high-value perennial plantation crops such as tea, rubber, coconut, palm oil, and coffee which generate significant export revenues and provide a major source of employment for rural populations in developing countries. Many studies in the literature have focused on climate change impacts on major annual crops; however, to date, there have been very few assessments of the economic impacts of climate change on perennial plantation agriculture. This thesis therefore seeks to estimate the impacts of climate change on two important aspects of plantation agriculture - crop production and labour demand - for the case of the tea plantation sector in Sri Lanka, as an example of a high-value perennial plantation crop in a developing country. The thesis also aims to identify enablers and barriers of adaptation to climate change for this sector of Sri Lanka’s economy.
The impacts of climate change on production in Sri Lanka’s tea plantations are studied at estate-level (the primary decision making production unit) across all of the country’s tea growing regions using monthly resolution primary data for the period 2000-2014. The study employs a novel two-stage panel data approach to analyse weather and climate change effects on tea production and then to estimate production impacts for the short-, medium- and long-term future under three different global emissions scenarios. These analyses indicate that a hotter and wetter climate will have a detrimental effect on production. In high, medium and low emissions futures, the predictions show a negative proportional impact on production from increased rainfall and increased average temperature. On average across the data sample, a 12% decline in annual tea production is predicted under a high emissions scenario by 2050.
The impacts of climate change on labour demand in tea plantations in Sri Lanka are investigated by implementing a panel structural model of profit maximisation based on a normalised quadratic functional form. The analysis uses historical primary data on estate profits, input prices and output prices, together with monsoonal rainfall, temperature and wet days for years between 2002-2014 to quantify climate impacts on estates’ demand for labour. Anticipated changes in rainfall are predicted to reduce annual labour demand by 2.6% across the tea plantation sector. This could have considerable social and welfare implications, particularly for the Indian Tamil women who comprise the majority of the sector’s workforce.
Plantation agriculture is likely to be highly vulnerable to climate change because of its reliance on rain-fed production, long economic life span and the inability to easily switch crops due to high upfront capital costs. These distinct differences between annual and perennial agriculture, and the important role which plantation cropping plays in developing world agriculture, suggest that it is important to identify factors which affect choice of climate adaptation options in perennial crop production. Comprehensive knowledge of available adaptation options is of utmost importance if Sri Lanka’s tea estate managers are to counteract production losses from climate change and maintain their competitiveness in the international market. This is also vital for efficient and effective channeling of society’s resources to address the consequences of climate change. Employing data derived from face-to-face interviews with 50 tea estate managers in Sri Lanka, this study examines factors affecting choice of preferred adaptation options, barriers to adaptation and associated policy implications for tea production in Sri Lanka, as an example of a perennial tree crop system in a developing country.
Tea estate managers are already adapting to a changing climate; however, particular adaptation methods are only adopted in some situations and locations. Multinomial logit analysis of data from estate manager interviews indicates that availability of information on climate change, company size, tea growing elevation, and observed increases in temperature and rainfall are key factors influencing the choice of preferred adaptation option. Analysis also finds that barriers such as a lack capital, inadequate access to near-term and medium-term climate knowledge, and poor governmental and institutional support may prevent estate managers from experimenting with new adaptation options. Policies should, therefore, be aimed at promoting new adaptation options through information exchange between stakeholders and integrating climate change adaptation with Sri Lanka’s national sustainable developmental goals. The primary message of the adaptation analysis in this study is that governmental and institutional support and involvement are critical requirements for facilitating effective adaptation.
Findings from the thesis will help inform decision makers of the likely impacts of climate change on plantation cropping systems, and provide insights into barriers to adaptation and potential policy responses to improve the effectiveness of adaptation.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Poulter, Rachel. "Investigating the role of soil constraints on the water balance of some annual and perennial systems in a Mediterranean environment /." Connect to this title, 2005. http://theses.library.uwa.edu.au/adt-WU2006.0018.
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Labuschagne, Johan. "Nitrogen management strategies on perennial ryegrass - white clover pastures in the Western Cape Province /." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019.1/1385.
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Sencan, Secil. "Decision Tree Classification Of Multi-temporal Images For Field-based Crop Mapping." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605503/index.pdf.
Full textAbstract:
ABSTRACT
DECISION TREE CLASSIFICATION OF MULTI-TEMPORAL IMAGES FOR FIELD-BASED CROP MAPPING
Sencan, Seçil M. Sc., Department of Geodetic and Geographic Information Technologies Supervisor: Assist. Prof. Dr. Mustafa Tü
rker August 2004, 125 pages A decision tree (DT) classification approach was used to identify summer (August) crop types in an agricultural area near Karacabey (Bursa), Turkey from multi-temporal images. For the analysis, Landsat 7 ETM+ images acquired in May, July, and August 2000 were used. In addition to the original bands, NDVI, PCA, and Tasselled Cap Transformation bands were also generated and included in the classification procedure. Initially, the images were classified on a per-pixel basis using the multi-temporal masking technique together with the DT approach. Then, the classified outputs were applied a field-based analysis and the class labels of the fields were directly entered into the Geographical Information System (GIS) database. The results were compared with the classified outputs of the three dates of imagery generated using a traditional maximum likelihood (ML) algorithm. It was observed that the proposed approach provided significantly higher overall accuracies for the May and August images, for which the number of classes were low. In May and July, the DT approach produced the classification accuracies of 91.10% and 66.15% while the ML classifier produced 84.38% and 63.55%, respectively. However, in August nearly the similar overall accuracies were obtained for the ML (70.82%) and DT (69.14%) approaches. It was also observed that the use of additional bands for the proposed technique improved the separability of the sugar beet, tomato, pea, pepper, and rice classes.
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Sherrington, Christopher Alan. "Socio-economic constraints on renewable energy in the UK : understanding barriers to the development of perennial energy crops and onshore windpower." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/27376.
Full textAbstract:
In seeking both to tackle climate change and ensure that the UK has a secure supply of affordable energy, the UK Government is proposing a significant expansion in the generation of energy from renewable sources. Under the Renewable Energy Directive, the UK is committed to providing renewable sources for 15% of its total energy use by 2020. While there is considerable theoretical potential, a number of socio-economic constraints threaten the achievement of this target. This research develops a more quantitative understanding of such constraints for two renewable energy sources with significant potential; perennial energy crops, and onshore wind power. For perennial energy crops such as Short Rotation Coppice (SRC) Willow, and Miscanthus, a major constraint is the extent to which UK farmers will commit land to the production of these relatively novel crops. For onshore wind power, a key constraint is that of public perception, related primarily to the visual impact on landscapes. The research uses a number of approaches, drawing on socialpsychology techniques, mathematical programming, and cost-benefit analysis, to develop a better understanding of the nature and extent of key barriers. As a result, a number of policy relevant findings lead to the identification of cost-effective ways in which barriers to development can be addressed.
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Hoeppner, Jeffrey Wayne. "The effects of legume green manures, perennial forages, and cover crops on non-renewable energy use in western Canadian cropping systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ62754.pdf.
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Nguyen, Hoang Khanh Linh, and Bich Ngoc Nguyen. "Management current land use of perennial industrial crops by NDVI index: A case study in Chu Se District, Gia Lai Province, Vietnam." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-190588.
Full textAbstract:
Remote sensing and Geographic Information System (GIS) - an effective tool for managing naturalresources, is quite common application in establishing thematic maps. However, the application of this modern technology in natural resource management has not yet been popular in Vietnam, particularly mapping the land use/cover. Currently, land use/cover map is constructed as traditional methods and gets limitations of management counting due to time-consuming for mapping andsynthesis the status of land use/cover. Hence, information on the map is often outdated and inaccurate.The main objective of this study is to upgrade the accuracies in mapping current perennialcrops in Chu Se District, Gia Lai Province in Vietnam by interpreted NDVI index (Normalized Difference Vegetation Index) from Landsat 8-OLI (Operational Land Imager). The results of studyis satisfied the urgent of practical requirement and scientific research. There are 3 types of perennial industrial plants in the study area including rubber, coffee, and pepper, in which most coffee isgrown, with an area of over 10,000 hectares. The results also show that integration of remote sensing and GIS technology enables to map current management and distribution of perennial industrialplants timely and accurately. This application is fully consistent with the trend of the world, and in accordance with regulations of established land use/cover map, and the process could be appliedat other districts /towns or in higher administrative unitsViễn thám và hệ thông tin địa lý (GIS) là công cụ hữu hiệu để quản lý tài nguyên thiên nhiên, được ứng dụng khá phổ biến để thành lập các loại bản đồ. Tuy nhiên, việc áp dụng công nghệ hiện đại này trong lĩnh vực quản lý tài nguyên thiên nhiên ở Việt Nam chưa phổ biến, nhất là công tác xây dựng bản đồ hiện trạng sử dụng/độ phủ đất. Việc xây dựng bản đồ hiện trạng hiện nay vẫn theo phương pháp truyền thống, thường gặp nhiều hạn chế do thời gian tổng hợp và xây dựng bản đồ hiện trạng kéo dài, dẫn đến thông tin trên bản đồ bị lạc hậu và không chính xác. Mục tiêu chính của nghiên cứu này là nâng cao độ chính xác kết quả giải đoán ảnh viễn thám Landsat 8 bằng chỉ số NDVI (chỉ số khác biệt thực vật) để thành lập bản đồ hiện trạng sử dụng đất cây công nghiệp lâu năm ở huyện Chư Sê, tỉnh Gia Lai, Việt Nam. Từ đó quản lý hiện trạng sử dụng loại đất này phù hợp yêu cầu cấp bách thực tiễn sản xuất và nghiên cứu khoa học. Kết quả của nghiên cứu cho thấy có 3 loại hình cây công nghiệp trên địa bàn nghiên cứu gồm cây cao su, cà phê và hồ tiêu, trong đó cây cà phê được trồng nhiều nhất, với diện tích hơn 10.000 ha. Nghiên cứu cũng cho thấy, tích hợp công nghệ viễn thám và GIS cho phép quản lý hiện trạng và phân bố cây công nghiệp trong không gian một cách hiệu quả và nhanh chóng. Ứng dụng này hoàn toàn phù hợp với xu hướng của thế giới, đồng thời theo đúng quy định thành lập bản đồ hiện trạng sử dụng đất, và quy trình này có thể thực hiện được ở cấp huyện/thị xã hoặc đơn vị hành chính cấp cao hơn
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Ratnasoma, H. A. "Studies on the use of Pasteuria penetrans for control of root-knot nematodes and its field evaluation on perennial crops in Sri Lanka." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253457.
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MARTANI, ENRICO. "Conversion of perennial cropping systems to arable land: keyelements for an ecologically sustainable transition." Doctoral thesis, Università Cattolica del Sacro Cuore, 2021. http://hdl.handle.net/10280/96576.
Full textAbstract:
La coltivazione dei sistemi colturali poliennali su terreni marginali combina la produzione sostenibile di biomassa per diversi utilizzi a benefici di carattere ambientale come il sequestro del C atmosferico nel suolo. La limitata longevità di questi sistemi colturali (10-20 anni), fornisce la possibilità di sfruttarli come una tecnica temporanea per rigenerare la fertilità dei terreni marginali e di studiare il loro effetto nel lungo periodo sul carbonio del suolo. Con questa tesi, avevo l'obiettivo di studiare l'effetto della riconversione a coltura annuali dei sistemi agricoli poliennali sul carbonio del suolo: per raggiungere questo obiettivo, ho combinato ad una meta-analisi di letteratura sull'effetto della riconversione, con un esperimento di campo di lungo periodo, un esperimento di incubazione in laboratorio e l'uso di un modello matematico del carbonio del suolo. L'uso combinato di questi approcci mi ha permesso di mostrare il potenziale che i sistemi colturali poliennali hanno nel sostenere il sequestro del C ne suolo anche dopo la loro riconversione. Quindi i sistemi colturali poliennali sono una pratica sostenibile promettente che può essere integrata in rotazioni agricole di 13 anni sui terreni marginali del nord d'Italia per ripristinare il carbonio del suolo.The cultivation of perennial cropping systems on marginal lands combines the production of sustainable biomass for multiple uses with environmental benefits such as carbon (C) sequestration in soil. In this thesis, we studied the effect of perennial cropping system on soil C considering the scenario of perennial cropping systems reversion to arable land. The limited longevity (10-20 years) of perennial cropping systems, gives the possibility of using these crops as a temporary- option to restore soil fertility of marginal lands and to study the long-term legacy of these cropping systems on soil C. In this thesis I aimed to study the effect of perennial cropping systems reversion to arable land on soil C: to achieve this objective, I combined a literature meta-analysis on the effect of reversion of perennial cropping systems on soil C, with a long-term field experiment on perennial cropping systems, an incubation experiment and the use of a process-based soil C model. The combined use of these approaches gave me the chance to show the potential of perennial cropping systems to support C sequestration even after their reversion. Therefore, perennial cropping systems are a promising sustainable practice which could be integrated on a 13-year agricultural rotation on marginal lands of northern Italy to restore soil C.
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MARTANI, ENRICO. "Conversion of perennial cropping systems to arable land: keyelements for an ecologically sustainable transition." Doctoral thesis, Università Cattolica del Sacro Cuore, 2021. http://hdl.handle.net/10280/96576.
Full textAbstract:
La coltivazione dei sistemi colturali poliennali su terreni marginali combina la produzione sostenibile di biomassa per diversi utilizzi a benefici di carattere ambientale come il sequestro del C atmosferico nel suolo. La limitata longevità di questi sistemi colturali (10-20 anni), fornisce la possibilità di sfruttarli come una tecnica temporanea per rigenerare la fertilità dei terreni marginali e di studiare il loro effetto nel lungo periodo sul carbonio del suolo. Con questa tesi, avevo l'obiettivo di studiare l'effetto della riconversione a coltura annuali dei sistemi agricoli poliennali sul carbonio del suolo: per raggiungere questo obiettivo, ho combinato ad una meta-analisi di letteratura sull'effetto della riconversione, con un esperimento di campo di lungo periodo, un esperimento di incubazione in laboratorio e l'uso di un modello matematico del carbonio del suolo. L'uso combinato di questi approcci mi ha permesso di mostrare il potenziale che i sistemi colturali poliennali hanno nel sostenere il sequestro del C ne suolo anche dopo la loro riconversione. Quindi i sistemi colturali poliennali sono una pratica sostenibile promettente che può essere integrata in rotazioni agricole di 13 anni sui terreni marginali del nord d'Italia per ripristinare il carbonio del suolo.The cultivation of perennial cropping systems on marginal lands combines the production of sustainable biomass for multiple uses with environmental benefits such as carbon (C) sequestration in soil. In this thesis, we studied the effect of perennial cropping system on soil C considering the scenario of perennial cropping systems reversion to arable land. The limited longevity (10-20 years) of perennial cropping systems, gives the possibility of using these crops as a temporary- option to restore soil fertility of marginal lands and to study the long-term legacy of these cropping systems on soil C. In this thesis I aimed to study the effect of perennial cropping systems reversion to arable land on soil C: to achieve this objective, I combined a literature meta-analysis on the effect of reversion of perennial cropping systems on soil C, with a long-term field experiment on perennial cropping systems, an incubation experiment and the use of a process-based soil C model. The combined use of these approaches gave me the chance to show the potential of perennial cropping systems to support C sequestration even after their reversion. Therefore, perennial cropping systems are a promising sustainable practice which could be integrated on a 13-year agricultural rotation on marginal lands of northern Italy to restore soil C.
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Jonson, Sofia. "Multifunctional production systems in Brazil : Opportunities, barriers, and implementation." Thesis, Mittuniversitetet, Institutionen för ekoteknik- och hållbart byggande, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39250.
Full textAbstract:
As populations grow and the call for renewable energy increases, so does the demand for biomass. However, the sustainability of biomass production has been debated. Concerns involve both negative environmental impacts from agricultural production, as well as the effects of increased bioenergy use on food security. Multifunctional production systems are a potential solution to these issues where environmental benefits are promoted in addition to maintained or enhanced biomass output. This study investigates multifunctional production systems in Brazil, as well as incentives and barriers for implementation within the Brazilian context. A systematic literature review was used to identify previous research on multifunctional production systems in Brazil. The review was then complemented by semi-structured open-ended interviews with local experts. The study found that even though common terminology from the field of multifunctional production systems was not frequently used in the Brazilian context, the systems were both studied and implemented. It was also concluded that economic feasibility is a prerequisite for successful implementation. However, factors like environmental circumstances, farmers perceptions, knowledge, and traditions are also important. Thus, effective adoption requires strategies combining economic incentives, policy incentives as well as educational tools.2020-06-13
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Interlandi, Sebastiano. "Aspetti agronomici innovativi dello zafferano." Thesis, Università degli Studi di Catania, 2011. http://hdl.handle.net/10761/231.
Full textAbstract:
Lo zafferano (Crocus sativus L.) e' la specie piu' costosa al mondo. In Sicilia e' utilizzato per la produzione del formaggio tipico "Piacentinu ennese" DOP. La coltivazione di questa specie e' stata introdotta nell'isola da pochi anni, per cui e' necessario mettere a punto delle tecniche colturali idonee.
L'obiettivo di questo studio e' stato quello di valutare:
- l'effetto della grana del terreno sulla produzione di stimmi e bulbi di zafferano;
- la produttivita' in coltura poliennale;
- la propagazione in vitro.
Le prove sono state effettuate nel campo sperimentale dell'Universita' degli Studi di Catania (piana di Catania, a 10 m s.l.m.) ed in un'azienda tipica della Sicilia centrale (720 m slm); la propagazione in vitro e le analisi chimiche, sono state eseguite nei laboratori del CNR "Istituto per i Sistemi Agricoli e Forestali del Mediterraneo (ISAFOM) e "Istituto di Chimica biomolecolare" di Catania.
I risultati mostrano che i fiori e la produzione di stimmi, e' legata alla costituzione del terreno ed alle basse temperature verificatesi durante la fioritura. E 'interessante notare che nella coltura poliennale la qualita' del prodotto risulta sempre elevata appartenendo alla prima categoria ISO.
Per cio' che concerne la propagazione in vitro e' stata superata la prima fase di sviluppo delle plantule in vitro.
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Nguyen, Hoang Khanh Linh, and Bich Ngoc Nguyen. "Management current land use of perennial industrial crops by NDVI index: A case study in Chu Se District, Gia Lai Province, Vietnam: Research article." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A29090.
Full textAbstract:
Remote sensing and Geographic Information System (GIS) - an effective tool for managing naturalresources, is quite common application in establishing thematic maps. However, the application of this modern technology in natural resource management has not yet been popular in Vietnam, particularly mapping the land use/cover. Currently, land use/cover map is constructed as traditional methods and gets limitations of management counting due to time-consuming for mapping andsynthesis the status of land use/cover. Hence, information on the map is often outdated and inaccurate.The main objective of this study is to upgrade the accuracies in mapping current perennialcrops in Chu Se District, Gia Lai Province in Vietnam by interpreted NDVI index (Normalized Difference Vegetation Index) from Landsat 8-OLI (Operational Land Imager). The results of studyis satisfied the urgent of practical requirement and scientific research. There are 3 types of perennial industrial plants in the study area including rubber, coffee, and pepper, in which most coffee isgrown, with an area of over 10,000 hectares. The results also show that integration of remote sensing and GIS technology enables to map current management and distribution of perennial industrialplants timely and accurately. This application is fully consistent with the trend of the world, and in accordance with regulations of established land use/cover map, and the process could be appliedat other districts /towns or in higher administrative units.Viễn thám và hệ thông tin địa lý (GIS) là công cụ hữu hiệu để quản lý tài nguyên thiên nhiên, được ứng dụng khá phổ biến để thành lập các loại bản đồ. Tuy nhiên, việc áp dụng công nghệ hiện đại này trong lĩnh vực quản lý tài nguyên thiên nhiên ở Việt Nam chưa phổ biến, nhất là công tác xây dựng bản đồ hiện trạng sử dụng/độ phủ đất. Việc xây dựng bản đồ hiện trạng hiện nay vẫn theo phương pháp truyền thống, thường gặp nhiều hạn chế do thời gian tổng hợp và xây dựng bản đồ hiện trạng kéo dài, dẫn đến thông tin trên bản đồ bị lạc hậu và không chính xác. Mục tiêu chính của nghiên cứu này là nâng cao độ chính xác kết quả giải đoán ảnh viễn thám Landsat 8 bằng chỉ số NDVI (chỉ số khác biệt thực vật) để thành lập bản đồ hiện trạng sử dụng đất cây công nghiệp lâu năm ở huyện Chư Sê, tỉnh Gia Lai, Việt Nam. Từ đó quản lý hiện trạng sử dụng loại đất này phù hợp yêu cầu cấp bách thực tiễn sản xuất và nghiên cứu khoa học. Kết quả của nghiên cứu cho thấy có 3 loại hình cây công nghiệp trên địa bàn nghiên cứu gồm cây cao su, cà phê và hồ tiêu, trong đó cây cà phê được trồng nhiều nhất, với diện tích hơn 10.000 ha. Nghiên cứu cũng cho thấy, tích hợp công nghệ viễn thám và GIS cho phép quản lý hiện trạng và phân bố cây công nghiệp trong không gian một cách hiệu quả và nhanh chóng. Ứng dụng này hoàn toàn phù hợp với xu hướng của thế giới, đồng thời theo đúng quy định thành lập bản đồ hiện trạng sử dụng đất, và quy trình này có thể thực hiện được ở cấp huyện/thị xã hoặc đơn vị hành chính cấp cao hơn.
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Cattaneo, Francesca <1983>. "Land use change to perennial energy crops in Northern Italy: Effects on soil organic carbon sequestration and distribution, soil enzyme activities and microbial communities." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6640/1/Cattaneo_Francesca_tesi.pdf.
Full textAbstract:
Studies on soil organic carbon (SOC) sequestration in perennial energy crops are available for North-Central Europe, while there is insufficient information for Southern Europe.
This research was conducted in the Po Valley, a Mediterranean-temperate zone characterised by low SOC levels, due to intensive management.
The aim was to assess the factors influencing SOC sequestration and its distribution through depth and within soil fractions, after a 9-year old conversion from two annual systems to Miscanthus (Miscanthus × giganteus) and giant reed (Arundo donax).
The 13C natural abundance was used to evaluate the amount of SOC in annual and perennial species, and determine the percentage of carbon derived from perennial crops. SOC was significantly higher under perennial species, especially in the topsoil (0-0.15 m). After 9 years, the amount of C derived from Miscanthus was 18.7 Mg ha-1, mostly stored at 0-0.15 m, whereas the amount of C derived from giant reed was 34.7 Mg ha-1, evenly distributed through layers. Physical soil fractionation was combined with 13C abundance analysis. C derived from perennial crops was mainly found in macroaggregates. Under giant reed, more newly derived-carbon was stored in microaggregates and mineral fraction than under Miscanthus.
A molecular approach based on denaturing gradient gel electrophoresis (DGGE) allowed to evaluate changes on microbial community, after the introduction of perennial crops. Functional aspects were investigated by determining relevant soil enzymes (β-glucosidase, urease, alkaline phosphatase). Perennial crops positively stimulated these enzymes, especially in the topsoil. DGGE profiles revealed that community richness was higher in perennial crops; Shannon index of diversity was influenced only by depth.
In conclusion, Miscanthus and giant reed represent a sustainable choice for the recovery of soils exhausted by intensive management, also in Mediterranean conditions and this is relevant mainly because this geographical area is notoriously characterised by a rapid turnover of SOC.
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Cattaneo, Francesca <1983>. "Land use change to perennial energy crops in Northern Italy: Effects on soil organic carbon sequestration and distribution, soil enzyme activities and microbial communities." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6640/.
Full textAbstract:
Studies on soil organic carbon (SOC) sequestration in perennial energy crops are available for North-Central Europe, while there is insufficient information for Southern Europe.
This research was conducted in the Po Valley, a Mediterranean-temperate zone characterised by low SOC levels, due to intensive management.
The aim was to assess the factors influencing SOC sequestration and its distribution through depth and within soil fractions, after a 9-year old conversion from two annual systems to Miscanthus (Miscanthus × giganteus) and giant reed (Arundo donax).
The 13C natural abundance was used to evaluate the amount of SOC in annual and perennial species, and determine the percentage of carbon derived from perennial crops. SOC was significantly higher under perennial species, especially in the topsoil (0-0.15 m). After 9 years, the amount of C derived from Miscanthus was 18.7 Mg ha-1, mostly stored at 0-0.15 m, whereas the amount of C derived from giant reed was 34.7 Mg ha-1, evenly distributed through layers. Physical soil fractionation was combined with 13C abundance analysis. C derived from perennial crops was mainly found in macroaggregates. Under giant reed, more newly derived-carbon was stored in microaggregates and mineral fraction than under Miscanthus.
A molecular approach based on denaturing gradient gel electrophoresis (DGGE) allowed to evaluate changes on microbial community, after the introduction of perennial crops. Functional aspects were investigated by determining relevant soil enzymes (β-glucosidase, urease, alkaline phosphatase). Perennial crops positively stimulated these enzymes, especially in the topsoil. DGGE profiles revealed that community richness was higher in perennial crops; Shannon index of diversity was influenced only by depth.
In conclusion, Miscanthus and giant reed represent a sustainable choice for the recovery of soils exhausted by intensive management, also in Mediterranean conditions and this is relevant mainly because this geographical area is notoriously characterised by a rapid turnover of SOC.
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Clapham, S. Jennifer. "The abundance and diversity of small mammals and birds in mature crops of the perennial grasses Miscanthus x giganteus and Phalaris arundinacea grown for biomass energy." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/15629/.
Full textAbstract:
Low-carbon energy production is potentially a major method of reducing greenhouse gas emissions and anthropogenic climate change. In the UK, tall perennial grass crops show potential as “biomass crops”, providing renewable energy sources with a low net carbon cost. However, conversion of large areas of farmland to biomass production would constitute a major land-use change with possible negative effects on native biodiversity, particularly as some biomass crop types are not native to the UK. The aim of this thesis was to assess biological diversity within mature (>3 years old) crops of non-native Miscanthus x giganteus and native Phalaris arundinacea. Biomass crop structural characteristics and management regimes were recorded, and their biodiversity was surveyed with particular reference to birds and small mammals in comparison with adjacent land uses. Food resources in terms of non-crop vegetation and invertebrates were also recorded. Live-trapping revealed eight species of small mammal in the study crops, including a conservation priority species, the harvest mouse Micromys minutus, which was most abundant in Phalaris crops. Phalaris also contained the highest small mammal diversity, but the field headlands held the greatest small mammal abundance. Trapping and direct observations revealed a higher abundance and diversity of birds in the Miscanthus crops in comparison with Phalaris. Most of the bird species found in biomass crops were associated with woodland or reedbed rather than farmland habitat. Phalaris crops had a higher percentage of ground cover of the crop itself and non-crop vegetation, whereas Miscanthus fields had greater cover of crop litter. Miscanthus crops contained fewer invertebrates than Phalaris or the field headlands. Management specific to biomass grass crops involves harvest in spring, thus providing winter habitat of importance to birds and small mammals. The crop fields also provide a refuge for invertebrates and non-crop vegetation and overall, supported high levels of biodiversity.
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Pardon, Lénaïc. "Modelling of the nitrogen budget of oil palm plantations to help reduce losses to the environment. Case study in Sumatra, Indonesia." Thesis, Paris, Institut agronomique, vétérinaire et forestier de France, 2017. https://researchonline.jcu.edu.au/52952/1/52952-pardon-2017-thesis.pdf.
Full textAbstract:
Humanity faces the challenges of urgently decreasing the environmental impact of agriculture, shifting diets and increasing food production. Oil palm is a tropical perennial crop emblematic of these challenges. While its cultivation can be associated with environmental impacts, oil palm can produce 3 to 7 t of edible oil ha⁻¹ in optimal conditions, which is 7 to 10 fold higher than in annual oil crops. In this context, improving palm oil production sustainability is crucial for both reducing negative environmental impacts and ensuring food security.
Application of synthetic nitrogen (N) fertilisers was identified as a major source of environmental impacts associated with the cultivation of oil palm. Life cycle assessments of palm oil have already been performed to help quantify impacts and identify potential improvements of management practices. However, the only available emission models to estimate N losses to environment are generally valid for annual crops and temperate climate conditions. The use of such general models in life cycle assessment may lead to very uncertain results or to low sensitivity of assessments to management practices.
The overall objective of this research work was to help identify management practices to reduce N losses in the environment. The core of the work was hence to develop a model that estimates all N losses in oil palm plantations, while being sensitive to management practices. The study focused on N fluxes in industrial oil palm plantations on mineral soils.
We performed four steps in order to complete the objectives of this research work. First, we conducted a literature review of all the existing knowledge about N fluxes and losses in plantations. Second, we compared 11 existing models that may be used to predict N losses in plantations. Third, we performed an in-depth Morris's sensitivity analysis of one of the models, the APSIM-Oil palm process-based model. Fourth, we used all the information identified in the previous chapters, together with expert knowledge, to build IN-Palm, an agri-environmental indicator for N losses in oil palm plantations. We used the INDIGO® method and the fuzzy decision tree modelling approach to develop IN-Palm, and we validated this indicator using a field dataset of N leaching from a plantation in Sumatra, Indonesia.
Our literature review and model comparison showed that oil palm peculiarities may impact significantly N dynamics and losses. We identified research gaps and uncertainties about N losses, their drivers and the modelling of oil palm peculiarities. We identified the main drivers of N losses and yield in the APSIM-Oil palm process-based model. We built IN-Palm, which uses 21 readily available input variables to estimate each N loss pathway. IN-Palm predictions of N leaching were acceptable, and IN-Palm has shown efficient to help testing management changes.
This research constitutes a comprehensive synthesis of the available knowledge and models for N fluxes and losses in oil palm plantations. One of the main results is a novel agri-environmental indicator, IN-Palm, operationally-oriented, sensitive to local practices and environmental conditions, as well as potentially useable as an emission model for holistic approaches such as life cycle assessment. The INDIGO® method and fuzzy decision tree modelling approach were shown to be very well adapted for building agri-environmental indicators in contexts of knowledge scarcity. This indicator can be a useful base for further research about using agri-environmental indicators to reduce uncertainty in life cycle assessment, and for future adaptations for other tropical perennial crops.
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Poulter, Rachel. "Investigating the role of soil constraints on the water balance of some annual and perennial systems in a Mediterranean environment." University of Western Australia. Faculty of Agriculture, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0018.
Full textAbstract:
This thesis compares the in situ water balance of common annual production systems (wheat, lupin, subclover and serradella) with a grazed perennial system (lucerne) at a site in the Avon Catchment, Western Australia. Using a physically-based water balance approach the value of a plant based solution in redressing the hydrological imbalance that has become a feature of much of the dryland agricultural region of Western Australia is investigated. The effectiveness of lucerne in providing greater available storage for buffering large rainfall events, as compared to the annual systems, is illustrated. Continued transpiration following out-of-season rainfall events maintains a larger available storage capacity. In contrast, the annual systems that are fallow over summer only withdrew a small fraction of water by soil evaporation between rainfall events. Under annual systems, the profile moisture store was sequentially increased to the extent that additional increments of rainfall could potentially contribute to deep drainage. A particular focus of this study has been to investigate the presence of soil constraints to root growth, and to assess how these constraints affect the water balance. A site survey indicated the soil penetration resistance was sufficient to impose a physical constraint to root growth. Published literature on the site shows soil acidity is also at a level imposing chemical constraints to root growth. A root growth model “Rootmodel”, for predicting root growth with and without soil constraints is examined in detail as a method for providing root growth parameters for inclusion into the numerical water balance model, SWIM based on Richard’s equation. Functions developed from “Rootmodel” adequately describe the effect of profile limitations to root growth, such as soil strength, moisture availability and temperature. Recommendations are made for inclusion of a growth suppressing function in “rootmodel” based on the chemical limitation of low pH. The effects of soil acidity on the root growth of several species is investigated experimentally and the resultant root data provided a reference point by which the simplified prediction of root growth built into SWIM could be adjusted using a linear reduction function. A similar linear reduction function is also employed to impose a physical constraint in the form of high penetration resistance.
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De, Faveri Joanne. "Spatial and temporal modelling for perennial crop variety selection trials." Thesis, 2013. http://hdl.handle.net/2440/83114.
Full textAbstract:
This thesis involves the investigation and development of methods for analysing data from variety selection trials in perennial crops. This involves identifying best varieties from data collected at multiple times in field trials, often from multiple locations and involving multiple traits. For accurate variety predictions the methods for analysis of such data need to account for the spatial correlation typically present in field trials and the temporal correlation induced by the repeated measures nature of the data. The methods also need to model the variety effects over time. The methods presented are based on the linear mixed model and estimation is performed using residual maximum likelihood (REML). Spatial analysis methods are applied to data from multiple harvest times for two perennial crop data sets. These analyses show that spatial correlation is evident and the spatial analysis methods improve model fit. Simulation studies also show the spatial analysis methods provide better predictions of variety effects (closer to the true effects). As the data from perennial crop variety selection trials is measured over time there is also a need to account for the temporal correlation between measurements. Separable models are presented that model the spatial and temporal residual covariance structure. These methods are suitable for large numbers of harvests. Application to a multi-harvest lucerne breeding data set shows these models to be an improvement on historical analysis approaches. At the genetic level the variety effects need to be modelled over time. Two approaches are presented. The first approach involves applying factor analytic models to variety by harvest effects and using clustering to aid in interpretation and selection. The second approach uses cubic smoothing spline random regression. These approaches are applied to data from two traits from a lucerne breeding trial and are shown to successfully model the variety by harvest effects and aid in selection. As data is usually obtained from multiple trials at different locations, the above approaches are extended to the multi-environment situation and applied to a multi-harvest, multi-environment lucerne data set. While the separable spatio-temporal residual models show an improvement on analysing each harvest time separately, they are very restrictive in that they assume common spatial correlation parameters across harvests (or traits). The initial spatial analyses on the two multi-harvest perennial crop data sets reveal that spatial correlation often varies between harvests and between traits. A more suitable non-separable covariance model is investigated that allows for differing spatial correlation across time or traits. The approach is based on the Multivariate Autoregressive model, initially for spatial correlation in one direction. Subsequently the model is extended to the two directional row-column situation using the theory of Multivariate Conditional Autoregressive models. These models are applied to the lucerne multi-harvest and multi-trait data using code written in R, and are shown in most cases to be a significant improvement to the separable residual models previously investigated.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2013
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Karimi, Dehkordi Rezvan. "Downward movement of nitrate and phosphorus from hog manures in annual and perennial cropping systems." 2015. http://hdl.handle.net/1993/30617.
Full textAbstract:
Excess nitrate-N concentration (>10 mg L-1) in drinking water can cause significant risk to human health. Also, at very low concentration (0.035-0.1 mg P L-1), phosphorus is considered as a pollutant due to its effects of promoting algal growth and eutrophication of surface waters. This thesis’ research was conducted at two different sites. The first study was conducted at Carman on a sandy loam soil with cropping system, perennial versus annual, as the main plot and manure nutrient management system, as the subplot to measure nitrate and phosphorus leaching from hog manures. The second field experiment, located northwest of the town of Carberry, Manitoba, was conducted on a loamy sand soil. A two year rotation was employed for the annual cropping systems with a randomized complete block design. Treatments included two rates of liquid hog manure (LH-5000, LH-2500), two rates of fertilizers (F5000, F2500) corresponding to the amount of available nitrogen in the two rates of hog manure a compost treatment (Com-2500) and a control for a total of six treatments. The results from Carman site showed that while a substantial amount of nitrate-nitrogen was lost from the annual plots (40 to 60 kg ha-1 in 2010 and 23 to 60 kg ha-1 in 2011), a negligible amounts of nitrate was lost from the perennial (< 1 kg ha-1). There was no evidence of significant downward movement of phosphorus below the top 15 cm soil layer in this study. However, repeated, annual application of manure at an N-based rate resulted in increased soil test P. In Carberry, total N leaching of fertilizer amended plots was greater than in plots that received manure. Based on the results, application of liquid hog manure at the rate of 2500 gallon ac-1 was economically and environmentally more desirable and is recommended. We applied the multi-layer water balance model, VSMB, to the data that we generated in the field to gain an understanding of how well the model will simulate the loss of water that we measured from the lysimeters. The simulation study showed that the VSMB model grossly underestimated the amount of leached water, possibly due to an overestimation of evapotranspiration.October 2015