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1
Camara, Rodrigo, Camila Santos da Silva, Gilsonley Lopes dos Santos, Gabriel Santos Aguiar, Marcos Gervasio Gervasio Pereira, Cristiane Figueira Silva, and Eliane Maria Ribeiro Silva. "PHYSICAL, CHEMICAL, AND BIOLOGICAL SOIL ATTRIBUTES UNDER ANALOG AGROFORESTRY SYSTEM AND PASTURE SITES." FLORESTA 50, no. 1 (December 20, 2019): 887. http://dx.doi.org/10.5380/rf.v50i1.57476.
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Analog agroforestry system uses native tree species to improve soil conditions and the microclimate of degraded areas. This study aimed to assess the impact of analog agroforestry on physical, chemical, and biological soil attributes. We tested the hypothesis that some of these attributes can be used as indicators of soil quality improvement compared to a managed pasture area. Two experimental sites were selected, an analog agroforestry site and a pasture site. In October 2016 (end of the dry season), soil samples were collected from the 0–5 and 5–10 cm depths and the soil fauna community was sampled using pitfall traps. The analog agroforestry system led to increased total abundance, total richness, mean richness, evenness, and diversity of the soil fauna community as well as higher gravimetric soil moisture, sand content, pH, calcium, magnesium, and sum of exchangeable bases, which are good indicators of soil quality. Adults of Coleoptera, Diptera, Gastropoda, Hymenoptera, Isopoda, Lepidoptera, Poduromorpha, Symphypleona, Pseudoscorpionida, Lepidoptera and larvae of Coleoptera, Diptera, Lepidoptera, and Neuroptera were the most abundant taxonomic groups in the analog agroforestry system.
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Parr, J. F., R. I. Papendick, S. B. Hornick, and R. E. Meyer. "Soil quality: Attributes and relationship to alternative and sustainable agriculture." American Journal of Alternative Agriculture 7, no. 1-2 (June 1992): 5–11. http://dx.doi.org/10.1017/s0889189300004367.
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AbstractDifferent chemical, physical, and biological properties of a soil interact in complex ways that determine its potential fitness or capacity to produce healthy and nutritious crops. The integration of these properties andine resulting level of productivity often is referred to as “soil quality.” Soil quality can be defined as an inherent attribute of a soil that is inferred from its specific characteristics and observations (e.g., compactability, erodibility, and fertility). The term also refers to the soil's structural integrity, which imparts resistance to erosion, and to the loss of plant nutrients and organic matter. Soil quality often is related to soil degradation, which can be defined as the time rate of change in soil quality.Soil quality should not be limited to soil productivity, but should encompass environmental quality, human and animal health, and food safety and quality. There is inadequate reliable information on how changes in soil quality directly affect food quality, or indirectly affect human and animal health. In characterizing soil quality, biological properties have received less emphasis than chemical and physical properties, because their effects are difficult to measure, predict, or quantify. Improved soil quality often is indicated by increased infiltration, aeration, macropores, aggregate size, aggregate stability, and soil organic matter, and by decreased bulk density, soil resistance, erosion, and nutrient runoff. These are useful, but future research should seek to identify and quantify reliable and meaningful biological/ecological indicators of soil quality, such as total species diversity or genetic diversity of beneficial soil microorganisms, insects, and animals.Because these biological/ecological indexes of soil quality are dynamic, they will require effective monitoring and assessment programs to develop appropriate databases for research and technology transfer. We need to know how such indexes are affected by management inputs, whether they can serve as early warning indicators of soil degradation, and how they relate to the sustainability of agricultural systems.
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PACHECO, FÁBIO PALCZEWSKI, LÚCIA HELENA PEREIRA NÓBREGA, MICHELLE TONINI, ARIANE SPIASSI, DANIELLE MEDINA ROSA, and CLÁUDIA TATIANA DE ARAÚJO DA CRUZ-SILVA. "PHYSICAL ATTRIBUTES OF SOIL AFTER SWINE WASTEWATER APPLICATION AS COVER FERTILIZER ON MAIZE CROP AND BLACK OATS SEQUENCE." Revista Caatinga 30, no. 4 (December 2017): 955–62. http://dx.doi.org/10.1590/1983-21252017v30n416rc.
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ABSTRACT The rate of swine wastewater application (SW) in agricultural production could result in the replacement of chemical fertilizers. However, SW destroys soil physical properties by decreasing pore bulk, which negatively affects both crop yield and development. In this context, this study aimed at monitoring the influence of swine wastewater as a cover fertilizer in maize and black oats in sequence on soil physical properties. Five application rates (0, 100, 200, 300 and 537 m3ha - 1 equivalent to 0, 11.2, 22.3, 33.5 and 60 kg ha-1 N, respectively, based on the average nitrogen concentration in SW) were tested with four replications each. In the studied area, soil porosity, density, and water content, before maize sowing and at the end of the cycles of maize and black oats, were determined by the volumetric ring method. Data were submitted for regression analyses. There was a reduction in the macroporosity and total porosity of the soil when the SW application rate, before maize cultivation, was higher. The introduction of black oats helped to improve the physical quality of the soil and reduced the compaction of the surface layer from 0 to 15 cm and 100 to 300 m3 ha-1 SW rates.
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Proffitt, APB, RJ Jarvis, and S. Bendotti. "The impact of sheep trampling and stocking rate on the physical properties of a red duplex soil with two initially different structures." Australian Journal of Agricultural Research 46, no. 4 (1995): 733. http://dx.doi.org/10.1071/ar9950733.
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The effect of sheep trampling and stocking rate on the physical properties of a red duplex soil with two initially different structures was examined over an 8 week period when the soil was wet following winter rains. The experimental site was located at Merredin in Western Australia where the average annual rainfall is 307 mm. A previous long-term tillage and gypsum trial at the experimental site had resulted in the development of contrasting topsoil structures. Three grazing treatments were imposed at the trial site: grazing at the normal high stocking rate (8 DSE ha-1), grazing at half the normal stocking rate (4 DSE ha-1), and no grazing (where pasture was mown to simulate grazing without trampling). Topsoil structure was assesed by measuring water-stable aggregation (> 2 mm diameter aggregates), the relative contribution of dispersion and slaking to structural instability (measured as soil strength on < 2 mm fine earth soil fractions), steady-state infiltration rates (at 10 mm tension), and in situ soil strength characteristics (measured as penetration resistance). At the end of the grazing period, all structure attributes measured showed that topsoil structure had been damaged as a result of sheep trampling. The magnitude of such structure damage was affected by the initial physical condition of the soil and stocking rate. When compared with ungrazed pasture, there was a greater decline in structural condition as a consequence of grazing on less well-structured soil than on better-structured soil. Halving the normal stocking rate reduced the degree of structure damage on both soils. Within-season variability in soil hydraulic properties was large. The temporal changes in infiltration rates were attributed to changes in drainage pore volume brought about by the growth and decay of pasture roots, the formation and disruption of a surface crust, and the processes of soil compaction and remoulding resulting from animal trampling (no direct measurements were made). The variability in hydraulic behaviour found in this study emphasizes the need to maintain consistent sampling dates and soil water contents at sampling in long-term studies on soil structure changes.
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Krnáčová, Zdena, Juraj Hreško, and Miriam Vlachovičová. "An evaluation of soil retention potential as an important factor of water balance in the landscape." Moravian Geographical Reports 24, no. 3 (September 1, 2016): 44–54. http://dx.doi.org/10.1515/mgr-2016-0016.
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AbstractThe ability of soil to retain water in its profile is one of the most important soil functions. It is expressed as the water storage capacity or retention capacity of the soil, and it is primarily affected by the physical properties of the soil. Given the fact that the direct measurement of hydrological data for the soil is very difficult in terms of capacity, statistically expressed pedotransfer functions (PTF) are currently used for the indirect estimation of hydrolimits. The data most commonly used for the PTF are easy-to-measure and usually readily available soil data on particle size, bulk density, organic carbon and morphometric parameters of the environment (e.g. slope of the relief, etc.). The listed pedotransfer functions are deficient for the complex evaluation of soil cover; given disagreements about the attributes, they cannot be directly used for the vector database of classified soil-ecological units in the Slovak Republic. Therefore, we have created a model of an algorithm from selected parameters compatible with the vector database of classified soil-ecological units, which also allows for the spatial distribution of the cumulative coefficient of water retention capacity (CWRC) for the soils of the SR. The results of this evaluation are presented using case studies of the areas of Levoča and Hriňová.
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Welivitiya, W. D. Dimuth P., Garry R. Willgoose, and Greg R. Hancock. "A coupled soilscape–landform evolution model: model formulation and initial results." Earth Surface Dynamics 7, no. 2 (June 26, 2019): 591–607. http://dx.doi.org/10.5194/esurf-7-591-2019.
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Abstract. This paper describes the coupling of the State Space Soil Production and Assessment Model (SSSPAM) soilscape evolution model with a landform evolution model to integrate soil profile dynamics and landform evolution. SSSPAM is a computationally efficient soil evolution model which was formulated by generalising the mARM3D modelling framework to further explore the soil profile self-organisation in space and time, as well as its dynamic evolution. The landform evolution was integrated into SSSPAM by incorporating the processes of deposition and elevation changes resulting from erosion and deposition. The complexities of the physically based process equations were simplified by introducing a state-space matrix methodology that allows efficient simulation of mechanistically linked landscape and pedogenesis processes for catena spatial scales. SSSPAM explicitly describes the particle size grading of the entire soil profile at different soil depths, tracks the sediment grading of the flow, and calculates the elevation difference caused by erosion and deposition at every point in the soilscape at each time step. The landform evolution model allows the landform to change in response to (1) erosion and deposition and (2) spatial organisation of the co-evolving soils. This allows comprehensive analysis of soil landform interactions and soil self-organisation. SSSPAM simulates fluvial erosion, armouring, physical weathering, and sediment deposition. The modular nature of the SSSPAM framework allows the integration of other pedogenesis processes to be easily incorporated. This paper presents the initial results of soil profile evolution on a dynamic landform. These simulations were carried out on a simple linear hillslope to understand the relationships between soil characteristics and the geomorphic attributes (e.g. slope, area). Process interactions which lead to such relationships were also identified. The influence of the depth-dependent weathering function on soilscape and landform evolution was also explored. These simulations show that the balance between erosion rate and sediment load in the flow accounts for the variability in spatial soil characteristics while the depth-dependent weathering function has a major influence on soil formation and landform evolution. The results demonstrate the ability of SSSPAM to explore hillslope- and catchment-scale soil and landscape evolution in a coupled framework.
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Aisenberg, Geison Rodrigo, Felipe Koch, Gustavo Zimmer, Gustavo Henrique Demari, Vinícius Jardel Szareski, Ivan Ricardo Carvalho, Manoela Andrade Monteiro, et al. "Sowing periods, agronomic performance and seed quality of soybean cultivars in the Planosol soil." 2019 13, (03) 2019 (March 20, 2019): 348–53. http://dx.doi.org/10.21475/ajcs.19.13.03.p994.
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Understanding of sowing in an ideal season for each region and cultivar is essential for the crop to reach each of its stages in more favorable climatic conditions. The objective of this study was to evaluate the influence of different sowing times on agronomic attributes of two soybean cultivars and the physiological quality of soybean seeds in soil type Eutrophic Haplic Planosol. The experimental design was completely randomized, in a factorial scheme 4 x 2, with four sowing times and two soybean cultivars, with eight replications. The sowing was executed at the beginning and end of November (1st and 2nd epochs) and beginning and end of January (3rd and 4th epochs), using the cultivars: Fundacep 64 RR and BMX Potência RR. The experiment was carried out in polyethylene vessels with volumetric capacity of 10 liters. The morphological attributes of the plants were evaluated, such as: height, stem diameter, number of pods and seeds per plant, 1000 seed weight, as well as seed germination and vigor. Seeding after January 1st negatively affected the agronomic behavior of soybean plants, with reduction of plant height, stem diameter, number of pods and seeds per plant. The sowing on November 1st favored the obtaining of seeds with lower physical quality in terms of 1000 seed weight; however, seeds with superior physiological performance. Late sowing showed an alternative for the production of soybean seeds in the South region of Rio Grande do Sul, mainly due to the higher quality of the seeds produced in this period.
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Findura, Pavol, Koloman Krištof, Ján Jobbágy, Peter Bajus, and Urszula Malaga‑Toboła. "Physical Properties of Maize Seed and its Effect on Sowing Quality and Variable Distance of Individual Plants." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 66, no. 1 (2018): 35–42. http://dx.doi.org/10.11118/actaun201866010035.
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Precision sowing has been a major thrust of agricultural engineering research for many years; however, most of the research and development work has dealt with seeders for agronomic crops. Sowing quality means required vertical (depth) and horizontal (spatial) spacing of seeds in the soil with minimal damage to the seeds. The spatial distribution of seeds (horizontal spacing) is given by distance between the rows and spacing of the seeds in a row. The objective of the study was the evaluation and comparison of the sowing quality of sowing machine JD MaxEmerge XP with mechanical filling of ladle holes with holding fingers within usage of seeds with different dimensional and shape attributes in agricultural conditions. As it was observed that shape attributes have a significant effect on seeding quality and at the end it affects emergency and whole further growth of maize seeds. Sowing machine JD MaxEmerge XP reached good results for the quality especially when using the angular seeds. It reached the sowing quality expressed by the standard deviation of 46.95–50.76 % when seeds PR 37 N01 and for seeds PR 37 N01 it is 47.43–48.73 %. Another evaluative criterion is dual sowing of seeds or plants (DRR), it was reached the average value 3.65–2.45 % for angular seeds and the average of 1.54–3.71 % for approximately spherical seeds.
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Ceresoli, Lavito Luiz, Luiz Ricardo Sobenko, Briane Kreitlov, and Robson Andre Armindo. "VARIABILIDADE ESPACIAL DOS ATRIBUTOS FÍSICO-HIDRÁULICOS DO SOLO EM UMA ÁREA E ESTIMATIVA DA LÂMINA DE IRRIGAÇÃO DE PRECISÃO." IRRIGA 1, no. 01 (June 18, 2018): 179. http://dx.doi.org/10.15809/irriga.2016v1n01p179-190.
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VARIABILIDADE ESPACIAL DOS ATRIBUTOS FÍSICO-HIDRÁULICOS DO SOLO EM UMA ÁREA E ESTIMATIVA DA LÂMINA DE IRRIGAÇÃO DE PRECISÃO Lavito Luiz Ceresoli1; Luiz Ricardo Sobenko2; Briane Kreitlov e Silva3 E Robson André Armindo4* 1 Eng. Agrônomo, UFPR; Curitiba, PR, Brasil.2 Doutorando em Engenharia de Sistemas Agrícolas, ESALQ/USP, Piracicaba, SP, Brasil.3 Mestranda em Ciência do Solo, UFPR, Curitiba, PR, Brasil.4 Professor Associado, Núcleo de Atividades de Engenharia e Biossistemas (NAEB), DSEA-UFPR, Curitiba, PR, Brasil. E-mail: rarmindo@gmail.com (autor correspondente). 1 RESUMO Neste trabalho, teve-se como objetivo apresentar duas estratégias de gerenciamento de lâminas de irrigação de precisão a partir da análise dos atributos físico-hidráulicos do solo e da evapotranspiração da cultura do milho de uma área agrícola localizada no município de Sorriso-MT. Os atributos físicos do solo têm grande importância para o dimensionamento e manejo dos sistemas de irrigação, em projetos onde se busca eficiência e adequada operação. Os atributos analisados da área foram: textura, densidade do solo e das partículas, porosidade total e de aeração, carbono, condutividade hidráulica e retenção de água no solo. Por meio dos resultados foram recomendados quatro mapas temáticos de lâminas de irrigação de precisão, sendo um a partir da variabilidade espacial (v.e.) da capacidade de água disponível (CAD), outro a partir da v.e. da água facilmente disponível (AFD) e os dois últimos a partir da correlação positiva dos mapas de classes dos atributos físico-hidráulicos do solo com os mapas de CAD e AFD. Palavras-chave: geoestatística; capacidade de água disponível; zona de manejo Ceresoli, L. L.; Sobenko, L. R.; Silva, B. K.; Armindo, R. A.SPATIAL VARIABILITY OF SOIL HYDRAULIC PROPERTIES AND IRRIGATION PRECISION DEPTH DETERMINATION 2 ABSTRACT This study aimed to present two strategies for managing irrigation precision. These strategies were based on hydraulic soil physical attributes and on corn evapotranspiration. The study was conducted an agricultural area located in Sorriso city, Mato Grosso state, Brazil. Texture, bulk and particle densities, porosity and air-filled porosity, carbon, hydraulic conductivity and water retention were analyzed in this area. By the results, four thematic maps of irrigation precision were recommended, one from the spatial variability (s.v.) of the available water capacity (AWC), another from readily water range s.v. (RAW) and the last two between the positive correlation of physical attributes maps and of AWC and RAW maps. Keywords: geostatistics, avaliable water capacity, and management zone.
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Alves, Pablo Fernando Santos, Silvânio Rodrigues dos Santos, Marcos Koiti Kondo, Rodinei Facco Pegoraro, and Arley Figueiredo Portugal. "SOIL CHEMICAL PROPERTIES IN BANANA CROPS FERTIGATED WITH TREATED WASTEWATER." Revista Caatinga 32, no. 1 (March 2019): 234–42. http://dx.doi.org/10.1590/1983-21252019v32n123rc.
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ABSTRACT Determining the effects of using wastewater as fertilizer on soil chemical properties allows a safe reuse of this effluent in agriculture. This study evaluated the effects of fertigation with tertiary treated wastewater (TTW) from the Janaúba sewage treatment plant on chemical properties of a Latosol (Oxisol) with banana crops of the Prata-Anã cultivar in the semiarid region of Brazil. A randomized complete block design with four replications was used to test four TTW rates (70%, 130%, 170%, and 200% of the limit of 150 kg ha-1 year-1 of Na that can be applied to the soil) and compare them to a control without TTW. Soil samples from the 0.0-0.2, 0.2-0.4, 0.4-0.6, and 0.6-0.8 m layers were collected at the end of the first crop cycle to evaluate soil chemical properties-pH, soil organic matter (SOM), P, K, Na, Ca, Mg, Al, potential acidity (H+Al), base saturation, B, Cu, Fe, Mn, Zn, remaining P, and electrical conductivity (EC). The use of TTW increases soil pH and decreases exchangeable Al content, thus, reduces the need for liming. However, Na contents increased faster than EC in the soil, indicating that the use of TTW tends to alter soil physical properties over time. The use of TTW had no effect on the soil OM, P, Ca, Mg, and micronutrients contents, potential acidity, and base saturation. The changes in soil chemical attributes observed at the end of the first crop cycle were not limiting to the banana crop.
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Batista, Lucas dos Santos, Raimundo Rodrigues Gomes Filho, Clayton Moura de Carvalho, Alceu Pedrotti, Igor Leonardo Nascimento Santos, Gregorio Guirado Faccioli, Sara Julliane Ribeiro Assunção, and Douglas Romeu da Costa. "Water infiltration rate in the soil under different uses and covers in the Poxim River basin, Sergipe, Brazil." International Journal for Innovation Education and Research 8, no. 11 (November 1, 2020): 321–39. http://dx.doi.org/10.31686/ijier.vol8.iss11.2756.
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Watersheds are units of planning and environmental management having a great importance in the management of water resources and their use. To this end, knowledge about the soil's physical and water attributes is of paramount importance in the context of water dynamics in aquifer recharge areas. Water infiltration rate into the soil is considered an important variable in the hydrological cycle, as the increase in this process can lead to a reduction in erosion and consequently greater groundwater recharge. Thus, the present work aimed to evaluate the soil water infiltration rate in the phytophysiognomy of the Poxim River basin in the State of Sergipe, in the agriculture, eucalyptus and forest areas, and to observe the effect of the infiltration water rate in areas of no-till, minimum and conventional cultivation. The soil water infiltration rate was obtained through the use of double cylinder infiltrometer and estimated through the mathematical models of Kostiakov, Kostiakov-Lewis, Horton and Philip. When making comparisons between the models for estimating of soil water infiltration rates, the Horton model showed a better fit compared to the other models used, and the type of soil cover that obtained the highest infiltration rate was the forest. No-till areas provided higher water infiltration rates in the soil, contributing to greater groundwater recharge.
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Mugnani, Robertson, Miller, and Platt. "Longleaf Pine Patch Dynamics Influence Ground-Layer Vegetation in Old-Growth Pine Savanna." Forests 10, no. 5 (April 30, 2019): 389. http://dx.doi.org/10.3390/f10050389.
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Old-growth longleaf pine savannas are characterized by diverse ground-layer plant communities comprised of graminoids, forbs, and woody plants. These communities co-exist with variable-aged patches containing similar-aged trees of longleaf pine (Pinus palustris Mill.). We tested the conceptual model that physical conditions related to the cycle of longleaf pine regeneration (stand structure, soil attributes, fire effects, and light) influence plant species’ composition and spatial heterogeneity of ground-layer vegetation. We used a chrono-sequence approach in which local patches represented six stages of the regeneration cycle, from open areas without trees (gaps) to trees several centuries old, based on a 40-year population study and increment cores of trees. We measured soil characteristics, patch stand structure, fuel loads and consumption during fires, plant productivity, and ground-layer plant species composition. Patch characteristics (e.g., tree density, basal diameter, soil carbon, and fire heat release) indicated a cyclical pattern that corresponded to the establishment, growth, and mortality of trees over a period of approximately three centuries. We found that plants in the families Fabaceae and Asteraceae and certain genera were significantly associated with a particular patch stage or ranges of patch stages, presumably responding to changes in physical conditions of patches over time. However, whole-community-level analyses did not indicate associations between the patch stage and distinct plant communities. Our study indicates that changes in composition and the structure of pine patches contribute to patterns in spatial and temporal heterogeneity in physical characteristics, fire regimes, and species composition of the ground-layer vegetation in old-growth pine savanna.
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Buchanan, S., J. Triantafilis, I. O. A. Odeh, and R. Subansinghe. "Digital soil mapping of compositional particle-size fractions using proximal and remotely sensed ancillary data." GEOPHYSICS 77, no. 4 (July 1, 2012): WB201—WB211. http://dx.doi.org/10.1190/geo2012-0053.1.
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The soil particle-size fractions (PSFs) are one of the most important attributes to influence soil physical (e.g., soil hydraulic properties) and chemical (e.g., cation exchange) processes. There is an increasing need, therefore, for high-resolution digital prediction of PSFs to improve our ability to manage agricultural land. Consequently, use of ancillary data to make cheaper high-resolution predictions of soil properties is becoming popular. This approach is known as “digital soil mapping.” However, most commonly employed techniques (e.g., multiple linear regression or MLR) do not consider the special requirements of a regionalized composition, namely PSF; (1) should be nonnegative (2) should sum to a constant at each location, and (3) estimation should be constrained to produce an unbiased estimation, to avoid false interpretation. Previous studies have shown that the use of the additive log-ratio transformation (ALR) is an appropriate technique to meet the requirements of a composition. In this study, we investigated the use of ancillary data (i.e., electromagnetic (EM), gamma-ray spectrometry, Landsat TM, and a digital elevation model to predict soil PSF using MLR and generalized additive models (GAM) in a standard form and with an ALR transformation applied to the optimal method (GAM-ALR). The results show that the use of ancillary data improved prediction precision by around 30% for clay, 30% for sand, and 7% for silt for all techniques (MLR, GAM, and GAM-ALR) when compared to ordinary kriging. However, the ALR technique had the advantage of adhering to the special requirements of a composition, with all predicted values nonnegative and PSFs summing to unity at each prediction point and giving more accurate textural prediction.
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Saqib, A. I., K. Ahmed, G. Qadir, M. Q. Nawaz, and A. R. Naseem. "Enhancing the Solubility and Reclamation Efficiency of Gypsum with H2SO4." Cercetari Agronomice in Moldova 52, no. 2 (June 1, 2019): 128–40. http://dx.doi.org/10.2478/cerce-2019-0013.
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Abstract An effective reclamation procedure of saline sodic soils is removal of undesirable Na+ by addition of some Ca2+ source paralleled with leaching of this sodium out of root zone. Nevertheless, gypsum being a direct source of Ca2+ is relatively insoluble in water. Its solubility can be increased with addition of H2SO4. Therefore, three years (2015 to 2018) study was plan to find out the optimal and economical level of H2SO4, which can increase the solubility and reclamation efficiency of gypsum for saline sodic soil in rice wheat crop-ping rotation. Treatments included were: T1, Control, T2, gypsum @ 100% of GR, T3, gypsum @ 100% of GR+10 kg H2SO4 acre−1, T4, gypsum @ 100% of GR+50 kg H2SO4 acre−1, T5, gypsum @ 100% of GR+100 kg H2SO4 acre−1. Before start of study, soil had pHs = 8.85, ECe = 4.85 (dS m−1), SAR = 43.82 (mmol L−1)1/2, GR = 4.10 (t. acre−1), BD = 1.65 (Mg m-3), HC = 0.33 (cm hr−1). Experiment was laid out in RCBD with three replications. Sulfuric acid and gypsum were applied (once) at the start of study in the respective treatment plots. Recommended dose of fertilizers, 150-90-60 NPK kg ha−1 for rice (Shaheen Basmati) and 160-114-60 NPK kg ha−1 for wheat (Faisalabad, 2008) was applied. Yield and yield determining attributes of each crop were recorded at physical maturity. After harvest of each crop, soil samples were collected and were analyzed for ECe, pHs, SAR, bulk density and hydraulic conductivity. Pooled data analysis revealed that maximum growth and yield determining factors of rice and wheat were recorded where gypsum was applied with H2SO4 at the rate of 50 and 100 kg acre−1. Soil physical and chemical properties, i.e. pHs, ECe, SAR bulk density and hydraulic conductivity were also substantially improved with combined application of gypsum and H2SO4 at the end of study. Both levels of H2SO4 at the rate of 50 and 100 kg acre−1 with gypsum proved equally to be the best in enhancing the solubility and reclamation efficiency of gypsum and showed the statistically (p≤ 0.05) similar results in increasing the yield of rice and wheat crop and improving the soil physical and chemicals properties. Therefore, H2SO4 at the rate of 50 kg acre−1 is recommended as most economical and optimum level, which can be used with gypsum as an effective ameliorative strategy for the salt affected soils.
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Melton, J. R., and V. K. Arora. "Sub-grid scale representation of vegetation in global land surface schemes: implications for estimation of the terrestrial carbon sink." Biogeosciences 11, no. 4 (February 21, 2014): 1021–36. http://dx.doi.org/10.5194/bg-11-1021-2014.
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Abstract. Terrestrial ecosystem models commonly represent vegetation in terms of plant functional types (PFTs) and use their vegetation attributes in calculations of the energy and water balance as well as to investigate the terrestrial carbon cycle. Sub-grid scale variability of PFTs in these models is represented using different approaches with the "composite" and "mosaic" approaches being the two end-members. The impact of these two approaches on the global carbon balance has been investigated with the Canadian Terrestrial Ecosystem Model (CTEM v 1.2) coupled to the Canadian Land Surface Scheme (CLASS v 3.6). In the composite (single-tile) approach, the vegetation attributes of different PFTs present in a grid cell are aggregated and used in calculations to determine the resulting physical environmental conditions (soil moisture, soil temperature, etc.) that are common to all PFTs. In the mosaic (multi-tile) approach, energy and water balance calculations are performed separately for each PFT tile and each tile's physical land surface environmental conditions evolve independently. Pre-industrial equilibrium CLASS-CTEM simulations yield global totals of vegetation biomass, net primary productivity, and soil carbon that compare reasonably well with observation-based estimates and differ by less than 5% between the mosaic and composite configurations. However, on a regional scale the two approaches can differ by > 30%, especially in areas with high heterogeneity in land cover. Simulations over the historical period (1959–2005) show different responses to evolving climate and carbon dioxide concentrations from the two approaches. The cumulative global terrestrial carbon sink estimated over the 1959–2005 period (excluding land use change (LUC) effects) differs by around 5% between the two approaches (96.3 and 101.3 Pg, for the mosaic and composite approaches, respectively) and compares well with the observation-based estimate of 82.2 ± 35 Pg C over the same period. Inclusion of LUC causes the estimates of the terrestrial C sink to differ by 15.2 Pg C (16%) with values of 95.1 and 79.9 Pg C for the mosaic and composite approaches, respectively. Spatial differences in simulated vegetation and soil carbon and the manner in which terrestrial carbon balance evolves in response to LUC, in the two approaches, yields a substantially different estimate of the global land carbon sink. These results demonstrate that the spatial representation of vegetation has an important impact on the model response to changing climate, atmospheric CO2 concentrations, and land cover.
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Lee, Minhyeong, Jooyoung Im, Gye-Chun Cho, Hee Hwan Ryu, and Ilhan Chang. "Interfacial Shearing Behavior along Xanthan Gum Biopolymer-Treated Sand and Solid Interfaces and Its Meaning in Geotechnical Engineering Aspects." Applied Sciences 11, no. 1 (December 25, 2020): 139. http://dx.doi.org/10.3390/app11010139.
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Recently, environment-friendly microbial biopolymer has been widely applied as a new construction material in geotechnical engineering practices including soil stabilization, slope protection, and ground injection. Biopolymer is known to exhibit substantial improvements in geotechnical properties, such as shear strength enhancement and hydraulic conductivity reduction, through the formation of direct ionic bonds with soil particles, especially clay particles. Moreover, the rheological characteristics (e.g., pseudoplasticity, shear-rate dependent thixotropy) of biopolymers render distinctive behaviors such as shear thinning and lubrication effect under a high strain condition, while recovering their viscosities and shear stiffnesses when they are at rest. To ensure the practical applicability of biopolymer-based soil treatment, it is important to understand the interfacial interaction (i.e., friction) between biopolymer-treated soil and adjoining structural members which can be constructed in a biopolymer-treated ground. Thus, in this paper, interfacial shearing behavior of biopolymer-treated soil along solid surfaces as well as internal shearing on biopolymer-soil matrix were explored via direct and interface shear test. Experimental results show a predominant effect of the soil moisture content on the interfacial shear behavior of biopolymer-treated soil which attributes to the rheology transition of biopolymer hydrogels. At low moisture content, condensed biopolymer biofilm mobilizes strong intergranular bonding, where the interfacial shear mainly depends on the physical condition along the surface including the asperity angle. In contrast, the biopolymer induced intergranular bonding weakens as moisture content increases, where most interfacial failures occur in biopolymer-treated soil itself, regardless of the interface condition. In short, this study provides an overall trend of the interfacial friction angle and adhesion variations of xanthan gum biopolymer-treated sand which could be referred when considering a subsequent structural member construction after a biopolymer-based ground improvement practice in field.
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Rho, Hyungmin, Paul Colaizzi, James Gray, Li Paetzold, Qingwu Xue, Bhimanagouda Patil, and Charles Rush. "Yields, Fruit Quality, and Water Use in a Jalapeno Pepper and Tomatoes under Open Field and High-tunnel Production Systems in the Texas High Plains." HortScience 55, no. 10 (October 2020): 1632–41. http://dx.doi.org/10.21273/hortsci15143-20.
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The Texas High Plains has a semi-arid, hot, windy climate that features high evapotranspiration (ET) demands for crop production. Irrigation is essential for vegetable production in the region, but it is constrained by depleting groundwater from the Ogallala Aquifer. High-tunnel (HT) production systems may reduce irrigation water demand and protect crops from severe weather events (e.g., hail, high wind, freezing) common to the region. The objective of this study was to compare yields, fruit quality, crop water use, and crop water use efficiency (WUE) of jalapeno pepper (Capsicum annuum L.) and tomatoes (Solanum lycopersicum L.) in HT and open field (OF) production systems. We hypothesized that the protection from dry and high winds by HT would improve yields and quality of fruits and reduce water use of peppers and tomatoes. During the 2018 and 2019 growing seasons, peppers and tomatoes were transplanted on two HT plots and two identical OF plots. Plastic mulch was used in combination with a surface drip irrigation system. Micrometeorological variables (incoming solar irradiance, air temperature, relative humidity, and wind speed) and soil physical variables (soil temperature and volumetric soil water) were measured. Air temperatures were significantly higher during the daytime, and wind speed and light intensity were significantly lower in HT compared with OF. Despite the lower light intensity, yields were greater in HT compared with OF. The fruits grown in HT did not show significant differences in chemical quality attributes, such as ascorbic acid and lycopene contents, compared with those grown in OF. Because of protection from dry, high winds, plants in HT required less total water over the growing seasons compared with OF, resulting in increased WUE. The 2018 and 2019 data showed that HT production is advantageous as compared to conventional OF production in terms of increased WUE and severe weather risk mitigation for high-value vegetable production in the Texas High Plains.
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D’Ambrosio, D., S. Di Gregorio, and G. Iovine. "Simulating debris flows through a hexagonal cellular automata model: SCIDDICA S<sub>3–hex</sub>." Natural Hazards and Earth System Sciences 3, no. 6 (December 31, 2003): 545–59. http://dx.doi.org/10.5194/nhess-3-545-2003.
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Abstract. Cellular Automata (CA) represent a formal frame for dynamical systems, which evolve on the base of local interactions. Some types of landslide, such as debris flows, match well this requirement. The latest hexagonal release (S3–hex) of the deterministic model SCIDDICA, specifically developed for simulating debris flows, is described. For CA simulation purposes, landslides can be viewed as a dynamical system, subdivided into elementary parts, whose state evolves exclusively as a consequence of local interactions within a spatial and temporal discretum. Space is the world of the CA, here constituted by hexagonal cells. The attributes of each cell ("substates") describe physical characteristics. For computational reasons, the natural phenomenon is "decomposed" into a number of elementary processes, whose proper composition makes up the "transition function" of the CA. By simultaneously applying this function to all the cells, the evolution of the phenomenon can be simulated in terms of modifications of the substates. SCIDDICA S3–hex exhibits a great flexibility in modelling debris flows. With respect to the previous releases of the model, the mechanism of progressive erosion of the soil cover has been added to the transition function. Considered substates are: altitude; thickness and energy of landslide debris; depth of erodable soil cover; debris outflows. Considered elementary processes are: mobilisation triggering and effect (T1), debris outflows (I1), update of landslide debris thickness and energy (I2), and energy loss (T2). Simulations of real debris flows, occurred in Campania (Southern Italy) in May 1998 (Sarno) and December 1999 (San Martino V.C. and Cervinara), have been performed for model calibration purposes; some examples of analysis are briefly described. Possible applications of the method are: risk mapping, also based on a statistical approach; evaluating the effects of mitigation actions (e.g. stream deviations, topographic alterations, channelling, embankments, bridges, etc.) on flow development.
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Melchers, R. E. "Models for Prediction of Long-Term Corrosion of Cast Iron Water Mains." Corrosion 76, no. 5 (November 20, 2019): 441–50. http://dx.doi.org/10.5006/3396.
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Corrosion of cast iron pipes buried in wet soils has long been associated with severe localized effects often attributed to microbiological influences and also with the chemical and physical properties of the soils. Despite more than 70 y of research effort, correlations have remained poor. Recently, the reasons for this have been elucidated, as reviewed briefly herein. Also, interpretation of data from actual cast iron pipes buried in a variety of soils for up to 129 y shows that two critical factors governing depth of local corrosion penetration are the type of soil and the compaction of that soil around the pipe. The latter influences the size of wet air-voids in the soil at the pipe surface. These cause differential aeration and associated severe localized corrosion. The other critical factor is the time of wetness of the soil/metal interface. This is related both to atmospheric precipitation (e.g., rain) and to soil permeability as governed by compaction. Microbiological corrosion has no influence unless essential nutrients continue to be available. These new views on an old subject permit the development of corrosion penetration models for longer-term corrosion.
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Fan, Yuan, Wuyan Shen, and Fangqin Cheng. "Reclamation of two saline-sodic soils by the combined use of vinegar residue and silicon-potash fertiliser." Soil Research 56, no. 8 (2018): 801. http://dx.doi.org/10.1071/sr18074.
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Amelioration of saline-sodic soil is essential to increase crop production and preserve the ecological environment in arid and semiarid regions. In this study, a pot experiment was conducted to investigate the effect of combined use of vinegar residue and silicon-potash (Si-K) fertiliser on the physical and chemical properties of two calcareous saline-sodic soils (saline soil (H-soil) and saline-sodic soil (S-soil)) and the growth of oat plants. The results showed that soil electrical conductivity was significantly decreased when vinegar residue was applied in two soils, which could be attributed to that vinegar residue could release H+, and react with HCO3−. When the combination of vinegar residue and Si-K fertiliser were used, equilibrium condition between monovalent cations and divalent cations could be altered. The divalent cations (e.g. Ca2+, Mg2+) were adsorbed at the cost of monovalent cations (Na+), resulting in the reduction of sodium adsorption ratio in the two soils. The decrease in soil pH was mainly due to the decrease in the activity of CO32− and HCO3−, which would react with H+ while vinegar residue was applied. As a saline-sodic soil, S-soil exhibited larger decrease in the pH compared with H-soil, a saline soil. The increase in the relative weight of wet stable macro-aggregate could be attributed to the release of Ca2+ and H+ and the flocculation of the dispersed clay by the application of Si-K fertiliser and vinegar residue. The application of Si-K fertiliser and vinegar residue contributed to a significant increase in survival rate and plant height of oat plants. It also led to increased relative water content and reduced electrolyte leakage for oat plants. This could be ascribed to the improvement of soil aggregate structure and nutrient supply, which promoted selective absorption and transportation of K+ over Na+ and decreased leaf damage. Therefore, the combined use of vinegar residue and Si-K fertiliser was considered to be a wise method for ameliorating two calcareous saline-sodic soils in Shanxi Province, Northern China.
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Silva, Venâncio Rodrigues e., José Luiz Rodrigues Torres, Danyllo Denner de Almeida Costa, Bruna de Souza Silveira, Dinamar Márcia da Silva Vieira, and Ernane Miranda Lemes. "Soil Physical Attributes in Long-Term Soil Management Systems (Tillage and No-till)." Journal of Agricultural Science 12, no. 4 (March 15, 2020): 194. http://dx.doi.org/10.5539/jas.v12n4p194.
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The period of implantation of the no-tillage system (NTS) is a fundamental factor to the dimension of the changes that occur to the soil's physical, chemical and biological attributes. Thus, the objective of this study was to evaluate the soil changes to the physical attributes and correlate the results to the soil organic matter in areas of different long-term soil management. The study was set as a completely randomised design, in a 4 × 4 factorial scheme, with four management systems [5 years NTS (NTS5); 17 years NTS (NTS17); conventional tillage system for 20 years (CTS20); native area (NA)], and four soil depths (0-0.05, 0.05-0.1, 0.1-0.2, 0.2-0.4 m), with five repetitions. Soil mechanical resistance to root penetration (RP), bulk density (SD), volumetric moisture (VM), macro (Ma), microporosity (Mi) and total porosity (TP), and the aggregation parameters were evaluated. The CTS20, NTS5 and NTS17 presented superior SD in the most superficial soil layers, which was not yet causing resistance to root development. The SD was the only physical attribute that correlated significantly with all the other soil attributes evaluated, indicating the importance of such attribute to evaluate soil quality to crops. The soil physical attributes found in the Cerrado native area followed the sequence of similarities: no-tillage system with 17 years (most similar), with five years and the conventional tillage system (less similar). The changes caused by the anthropic activity in the soil's physical attributes are more pronounced and perceptible in soil depths up to 0.2 m.
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Romano, Nunzio, and Mario Palladino. "Prediction of soil water retention using soil physical data and terrain attributes." Journal of Hydrology 265, no. 1-4 (August 2002): 56–75. http://dx.doi.org/10.1016/s0022-1694(02)00094-x.
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Ceddia, Marcos Bacis, Sidney Rosa Vieira, André Luis Oliveira Villela, Lenilson dos Santos Mota, Lúcia Helena Cunha dos Anjos, and Daniel Fonseca de Carvalho. "Topography and spatial variability of soil physical properties." Scientia Agricola 66, no. 3 (June 2009): 338–52. http://dx.doi.org/10.1590/s0103-90162009000300009.
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Among the soil formation factors, relief is one of the most used in soil mapping, because of its strong correlation with the spatial variability of soil attributes over a landscape. In this study the relationship between topography and the spatial variability of some soil physical properties was evaluated. The study site, a pasture with 2.84 ha, is located near Seropédica, Rio de Janeiro State, Brazil, where a regular square grid with 20 m spacing was laid out and georreferenced. In each sampling point, altitude was measured and undisturbed soil samples were collected, at 0.0-0.1, 0.1-0.2, and 0.2-0.3 m depths. Organic carbon content, soil texture, bulk density, particle density, and soil water retention at 10 (Field Capacity), 80 (limit of tensiometer reading) and 1500 kPa (Permanent Wilting Point) were determined. Descriptive statistics was used to evaluate central tendency and dispersion parameters of the data. Semivariograms and cross semivariograms were calculated to evaluate the spatial variability of elevation and soil physical attributes, as well as, the relation between elevation and soil physical attributes. Except for silt fraction content (at the three depths), bulk density (at 0.2-0.3 m) and particle density (at 0.0-0.1 m depth), all soil attributes showed a strong spatial dependence. Areas with higher elevation presented higher values of clay content, as well as soil water retention at 10, 80 and 1500 kPa. The correlation between altitude and soil physical attributes decreased as soil depth increased. The cross semivariograms demonstrated the viability in using altitude as an auxiliary variable to improve the interpolation of sand and clay contents at the depth of 0.0-0.3 m, and of water retention at 10, 80 and 1500 kPa at the depth of 0.0-0.2 m.
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Alves, Pablo F. S., Silvânio R. Santos, Marcos K. Kondo, Rodinei F. Pegoraro, and Edcássio D. Araújo. "Soil physical attributes in chemigated banana plantation with wastewater." Engenharia Agrícola 35, no. 6 (December 2015): 998–1008. http://dx.doi.org/10.1590/1809-4430-eng.agric.v35n6p998-1008/2015.
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ABSTRACT The feasibility of using sewage wastewater as a water and nutrient source for plants is an alternative to harness agricultural natural resource, observing its influence on the organic matter dynamics and soil energy. Our objective here was to evaluate the effects of applying different doses of effluent from a sewage treatment plant, in Janaúba – MG, Brazil, over the physical attributes of a soil grown with “Prata Anã” banana. From soil sample collection at depths of 0-20, 20-40, and 40-60 cm, we determined the following soil properties: soil density, total porosity, macroporosity, microporosity, organic matter, clay dispersed in water and stability of soil aggregate. The experimental design was in randomized blocks with four repetitions. Wastewater raising doses promoted increase in suspended solids, contributing to macroporosity reduction at 20-40 and 40-60 cm depths; as well as a reduction in organic matter within 0-20 cm layer. Clay dispersal was observed in the depths of 0-20 cm, being derived from an increase in sodium content. Concurrently, there was a reduction of soil aggregate stability.
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Junior, Elio Conradi, Affonso Celso Gonçalves Jr, Edleusa Pereira Seidel, Guilherme Lindner Ziemer, Juliano Zimmermann, Vinícius Henrique Dias de Oliveira, Daniel Schwantes, and Carlos Daniel Zeni. "Effects of Liming on Soil Physical Attributes: A Review." Journal of Agricultural Science 12, no. 10 (September 15, 2020): 278. http://dx.doi.org/10.5539/jas.v12n10p278.
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The objective of the present study was to gather information on the effects of liming on changes in soil physical attributes. Soil acidity, caused by natural ways, such as rain, weathering and decomposition of organic matter and by human interference, by the use of nitrogen fertilizer mainly ammonia and urea fertilizer contribute to the acidification of the soil. In this context liming is perform to correct soil pH and neutralize the effect of toxic elements. Numerous benefits of liming are known, but their influence on soil physical attributes is poorly studied. Liming directly affects some physical properties of the soil, such as flocculation, aggregates, density and porosity. Flocculation of soil particles initially is smallest, which promotes greater particle dispersion. However, it changes over time, since H+ and Al3+ ions tend to be subsumed by Ca2+ and Mg2+ increasing particle flocculation power which favors its approximation and aggregate formation. For soil aggregates, surface liming in improves soil aggregation by increasing the mean aggregate diameter with positive responses as dose increases. Density and porosity of soil also undergo changes. It is important to point out that liming also has the potential to alter the porous structure of the soil. Porosity liming promotes soil density reduction and increase influenced reducing macroporosity values and increase of total porosity and micropores values. The results of studies carried out present divergent and similar results according to the evaluated physical attributes. This is possibly due to the dynamics between liming under different edaphoclimatic conditions.
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Arshad, M. A., and G. M. Coen. "Characterization of soil quality: Physical and chemical criteria." American Journal of Alternative Agriculture 7, no. 1-2 (June 1992): 25–31. http://dx.doi.org/10.1017/s0889189300004410.
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AbstractThe impact of soil degradation on human welfare and the global environment presents a major challenge. A significant decline in soil quality has occurred worldwide through adverse changes in its physical, chemical and biological attributes and contamination by inorganic and organic chemicals. There is a need to develop criteria to evaluate soil quality so that the progress of any corrective action required by the international community can be monitored.There currently are no generally accepted criteria to evaluate changes in soil quality. This lack impedes the design and evaluation of meaningful soil management programs. This paper examines the principal physical and chemical attributes that can serve as indicators of a change in soil quality under particular agroclimatic conditions. Proposed indicators include soil depth to a root restricting layer, available water-holding capacity, bulk density/penetration resistance, hydraulic conductivity, aggregate stability, organic matter, nutrient availability/retention capacity, pH, and where appropriate, electrical conductivity and exchangeable sodium. We also discuss the justification for selecting these key attributes, their measurement, critical limits for monitoring changes in soil productivity, and future research needs in soil quality.
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Teixeira de Oliveira, Job, Rubens Alves de Oliveira, Domingos Sarvio Magalhães Valente, Isabela da Silva Ribeiro, and Paulo Eduardo Teodoro. "Spatial Relationships of Soil Physical Attributes with Yield and Lateral Shoot Growth of Garlic." HortScience 55, no. 7 (July 2020): 1053–54. http://dx.doi.org/10.21273/hortsci15082-20.
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Some compaction states cause changes in soil structure, resulting in increased soil density and soil resistance to penetration (RP). The objective of this study was: a) to analyze the variability of the studied attributes of the plant and the soil; b) define the linear and spatial correlations between plant and soil attributes; and c) to identify the best attributes that correlate spatially with garlic yield (GY) and lateral shoot growth (LSG) for the elaboration of spatial variability maps. The attributes evaluated were GY, apparent soil electrical conductivity (EC), mechanical resistance to penetration (MRP), soil volumetric moisture (SVM), plant water potential (WP), and LSG. The reach values of spatial dependence to be considered in future studies using the same attributes should be between 8 m for apparent soil EC and 23 m for RP. From a spatial point of view, garlic LSG could be estimated by indirect cokriging with soil RP. Values greater than 3000 kPa of soil RP indicated the sites with the lowest GYs.
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Oliveira, Marcela Pacola, Cassiano Garcia Roque, Gabriel Luis Piati, Rita de Cassia Felix Alvarez, Marco Antonio Camilo de Carvalho, Cid Naudi Silva Campos, and Paulo Eduardo Teodoro. "Cover crops, lime and gypsum influence on soil physical attributes." Bioscience Journal 37 (January 19, 2021): e37010. http://dx.doi.org/10.14393/bj-v37n0a2021-48248.
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Cover crops promote nutrient cycling, and lime and gypsum can alter the soil physical attributes. This study aimed to evaluate the effect of lime and gypsum rates applied to a no-tillage system with addition of residues of three cover crops on the soil physical attributes. This experiment was carried out in chapadão do sul-ms. The treatments were comprised of three cover crops (Urochloa ruziziensis, fallow, and Pennisetum glaucum), with gypsum (0, 2.3 and 4.6 Mg ha-1) and lime applied at a dose of 0, 2, 4, 6 Mg ha-1).The attributes evaluated were: soil density, macroporosity, microporosity, total porosity and penetration resistance. The soil of the experiment was classified an Oxisol. Cover crops and lime and gypsum improved macroporosity, microporosity and total porosity at all depths, 0-0.2 m. Millet presented lower values for penetration resistance with the lime application and without gypsum application. No residual effect on soil density was detected for lime and gypsum application or cover crops in the 0.1-0.2 m layer. Brazilian Cerrado producers will have a well-defined management system to follow aiming at improving the soil physical attributes.
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Alarcón-Jiménez, Milton F., Jesús H. Camacho-Tamayo, and Jaime H. Bernal. "Management zones based on corn yield and soil physical attributes." Agronomía Colombiana 33, no. 3 (September 1, 2015): 373–82. http://dx.doi.org/10.15446/agron.colomb.v33n3.51505.
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The need to increase the yield and thus the income of farmers and provide food for the growing population requires the search for more efficient and innovative ways for growing, such as management by zones or site-specific practices. This knowledge improves the process of decision making in agricultural production for better crop management. The aim of this study was to determine zones of agricultural management based on corn yield and its relationship with some physical attributes in an Oxisol on the Eastern plains of Colombia. For this, the soil sampling was done in a regular grid whose sampling points were spaced every 70 m, in an area of 37 ha. The studied soil attributes were penetration resistance (PR), texture, total porosity (TP), macropores, mesopores, micropores, saturated hydraulic conductivity (KS), bulk density (BD), particle density (PD), soil water content (SW) and yield. The results were analyzed using descriptive statistics, geostatistics and multivariate techniques. From these results, management zones were defined. The soil physical attributes presented high variability in the different regions of the sampled area. The methods used for characterizing the management zones, allowed for identifying which area presented the best physical characteristics, an area that also showed the highest production of maize, similar in the different methods that were studied.
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Phillips, I. R., and K. J. Sheehan. "Importance of surface charge characteristics when selecting soils for wastewater re-use." Soil Research 43, no. 8 (2005): 915. http://dx.doi.org/10.1071/sr05045.
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Land application represents a viable option in the management of wastewater such as landfill leachate. The surface charge and ion adsorption characteristics of the receiving soil will play an important role in the success of this disposal strategy. The surface charge characteristics of 6 soils with contrasting chemical and physical properties were studied using charge balance principles. The point of zero net proton charge density, point of zero salt effect and point of zero net charge, and the concentrations of permanent and variable charge as a function of pH, were determined for each soil. The presence and magnitude of permanent negative surface charge was largely dependant on clay mineralogy. All soils displayed increasing negative surface charge density with increasing pH. The magnitude of increase for any particular soil was dependent on the type and amount of colloids exhibiting variable surface charge. The increased negative surface charge was attributed to the ionisation of functional groups on organic matter, hydrous Fe and Al oxides, and edge sites of kaolinite and smectite. The variation in surface charge with pH conformed to charge balance principles for soils containing a mixture of both permanent and variable surface charge, but not for soils containing predominantly permanent surface charge. Proton-consuming processes (e.g. adsorption on permanent charge sites, neutralisation of inherent alkalinity) influenced the overall charge balance, particularly for soils with predominantly permanent surface charge. Ammonium adsorption from landfill leachate was measured as a function of pH for each soil type. Increased negative surface charge resulted in increased ammonium adsorption, and for most soils the preference of the newly created adsorption sites for ammonium remained relatively constant. Since many soils contain a mixture of colloids with permanent and variable surface charge, these charge characteristics and their effect on individual soil properties, contaminant availability, and contaminant mobility must be taken into account when evaluating the suitability of land for wastewater re-use.
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Camargo, Livia Arantes, José Marques Júnior, and Gener Tadeu Pereira. "Spatial variability of physical attributes of an alfisol under different hillslope curvatures." Revista Brasileira de Ciência do Solo 34, no. 3 (June 2010): 617–30. http://dx.doi.org/10.1590/s0100-06832010000300003.
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The influence of relief forms has been studied by several authors and explains the variability in the soil attributes of a landscape. Soil physical attributes depend on relief forms, and their assessment is important in mechanized agricultural systems, such as of sugarcane. This study aimed to characterize the spatial variability in the physical soil attributes and their relationship to the hillslope curvatures in an Alfisol developed from sandstone and growing sugarcane. Grids of 100 x 100 m were delimited in a convex and a concave area. The grids had a regular spacing of 10 x 10 m, and the crossing points of this spacing determined a total of 121 georeferenced sampling points. Samples were collected to determine the physical attributes related to soil aggregates, porosity, bulk density, resistance to penetration and moisture within the 0-0.2 and 0.2-0.4 m depth. Statistical analyses, geostatistics and Student's t-tests were performed with the means of the areas. All attributes, except aggregates > 2 mm in the 0-0.2 m depth and macroporosity at both depths, showed significant differences between the hillslope curvatures. The convex area showed the highest values of the mean weighted diameter, mean geometric diameter, aggregates > 2 mm, 1-2 mm aggregates, total porosity and moisture and lower values of bulk density and resistance to penetration in both depth compared to the concave area. The number of soil attributes with greater spatial variability was higher in the concave area.
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Cerri, Domingos Guilherme Pellegrino, and Paulo Sérgio Graziano Magalhães. "Correlation of physical and chemical attributes of soil with sugarcane yield." Pesquisa Agropecuária Brasileira 47, no. 4 (April 2012): 613–20. http://dx.doi.org/10.1590/s0100-204x2012000400018.
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The objective of this work was to evaluate the correlation between sugarcane yield and some physical and chemical attributes of soil. For this, a 42‑ha test area in Araras, SP, Brazil, was used. Soil properties were determined from samples collected at the beginning of the 2003/2004 harvest season, using a regular 100x100 m grid. Yield assessment was done with a yield monitor (Simprocana). Correlation analyses were performed between sugarcane yield and the following soil properties: pH, pH CaCl2, N, C, cone index, clay content, soil organic matter, P, K, Ca, Mg, H+AL, cation exchange capacity, and base saturation. Correlation coefficients were respectively ‑0.05, ‑0.29, 0.33, 0.41, ‑0.27, 0.22, 0.44, ‑0.24, trace, ‑0.06, 0.01, 0.32, 0.14, and 0.04. Correlations of chemical and physical attributes of soil with sugarcane yield are weak, and, per se, they are not able to explain sugarcane yield variation, which suggests that other variables, besides soil attributes, should be analysed.
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Pereira, Nayana Alves, João Carlos Medeiros, Julian Júnio de Jesus Lacerda, Jaqueline Dalla Rosa, Bruna Anair Souto Dias, Everaldo Moreira da Silva, Rafael Felippe Ratke, and Wanderson de Sousa Mendes. "Soil Physical Attributes Under Eucalyptus stands With Non-living and Living Plants." Journal of Agricultural Science 11, no. 3 (February 15, 2019): 197. http://dx.doi.org/10.5539/jas.v11n3p197.
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The conservation of ecosystems has benefited from planted forests which provide reforested wood reducing the pressure on deforestation of natural forests. Soil physical attributes determine soil water storage capacity; therefore, they play an important role on plant roots’ development which may compromise plant’s survival. The study tested the influence of soil physical and water attributes on the survival of Eucalyptus spp. clones under dry tropical climate. Two areas were selected, including one with living plants and a second with non-living plants of Eucalyptus spp. clones. Moreover, five soil profiles were studied in each area and the parameters estimated were soil bulk density, total porosity, saturated hydraulic conductivity, soil water retention curve, pores size distribution, available water capacity, and S index. Soil physical and hydric attributes did not differ between the area with living plants and the one with non-living plants. The saturated hydraulic conductivity in the area surface layer was high for both the living plants and non-living palnts; 331 mm h-1 and 294 mm h-1, respectively. The S index (to give the value) indicated that the structure was suitable for the development of Eucalyptus trees. Furthermore, it was possible to affirm that soil physical and water attributes of the studied areas were promising for the cultivation of Eucalyptus spp. in the dry tropical climate.
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Lima, Juliao Soares de Souza, Walas Permanhane Sturião, Ivoney Gontijo, and Samuel Assis Silva. "Spatial distribution of physical attributes of an Ultisol under papaya crop." Comunicata Scientiae 8, no. 4 (April 12, 2018): 526–36. http://dx.doi.org/10.14295/cs.v8i4.1669.
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The successful development of the root system of plants depends on the favorable conditions of soil physical attributes. The objective of this work was to study the spatial variability of physical attributes in an Ultisol cultivated with papaya. The soil was prepared mechanically plowing, harrowing, sulcal and subsoiler. In the center of the crop field was built a sampling grid with points spaced 5.7 m, totalizando129 georeferenced points. The soil samples at two depths (0 - 0.20 m, 0.20 - 0.40 m) were collected for four months after transplantation, to determine the total porosity (TP), soil moisture (Um), soil bulk density (BD) and soil penetration resistance in the planting row (PRPR) and in the traffic machines rows (PRRow). The soil penetration resistance in the planting row and in the traffic machines row was determined. The BD1 and BD2 showed the lowest CV values, and the data were fitted to the exponential and spherical models, respectively, with spatial dependence ranges of 20 and 28 m. At the layer of 0-0.20 m depth, the attributes showed the same spatial distribution pattern. At the layer of 0-0.20 m depth, the soil penetration resistance showed 7.5 times greater in the traffic machines region (rw spacing) than the value found in the planting row.
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Torres, José Luiz Rodrigues, Ana Carolina Marques Mendonça Silva, Haroldo Silva Vallone, Dinamar Márcia da Silva Vieira, Zigomar Menezes de Souza, and Ernane Miranda Lemes. "Sugarcane filter cake application to coffee crop and soil physical attributes." Revista em Agronegócio e Meio Ambiente 14, no. 2 (March 26, 2021): e7997. http://dx.doi.org/10.17765/2176-9168.2021v14n2e7997.
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Filter cakes are solid organic byproducts of the sugarcane industry that are generally used as fertilizers for crops such as coffee. Filter cake application has improved soil chemical, physical and microbiological attributes, especially for weathered soils. This study aimed to evaluate the influence of filter cake applications on the soil attributes cultivated with coffee in a Cerrado region. The study was conducted in a commercial coffee crop area (coffee cultivar Topázio MG 1190) in a Dystrophic Oxisol. The experimental design used was randomized blocks, in a factorial scheme of 4 x 4, with four doses of filter cake applied in the planting furrow (0, 4, 8, 12 L m-1) and four soil depths (0-0.1, 0.1-0.2, 0.2-0.3, 0.3-0.4 m). Soil density, soil mechanical resistance to root penetration, moisture, porosity (micro, macro, and total) and aggregate stability were evaluated. In general, the application of sugarcane filter cake over a long period has little effect on the soil's physical attributes, regardless of the filter cake rate used in the coffee crop. Only the soil porosity is affected by 12 L m-1 of filter cake, increasing the micro and macroporosity of the soil and promoting adequate conditions for the growth of coffee root, which can generate large soil water retention, benefiting coffee crops in the long-term.
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Corrêa, Robson Schaff, and Antônio Francisco Jurado Bellote. "Soil attributes and biomass yield from Pinus caribaea var. Hondurensis." CERNE 17, no. 2 (June 2011): 181–87. http://dx.doi.org/10.1590/s0104-77602011000200004.
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Biomass yield from Pinus caribaea var. hondurensis is conditional on soil attributes. With the silvicultural practice currently being used in Brazil, Pinus stands might produce lower yields due to nutrient shift from harvest and due to changes in the edaphic environment from mechanization. Therefore, this study aims to evaluate chemical and physical soil attributes and determine which are correlated with higher biomass yields. Four commercial stands were selected, with differing growth patterns, each having four trees selected from the dominant layer, in addition to soil samples for chemical and physical analyses. Soil attributes and biomass yield data were submitted to analysis of variance (ANOVA), means were compared by the Tukey test, and the Pearson correlation coefficient was determined. Chemical attributes directly or indirectly associated with the sum of bases and physical attributes associated with water availability were found to be related to biomass yield.
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Gravina, Otavio Silveira, Glenio Guimarães Santos, Vladia Correchel, Gustavo Cassiano da Silva, Lucas de Castro Medrado, Rilner Alves Flores, Márcio Mesquita, and Eduardo da Costa Severiano. "Physical Attributes of Ferralsol in Fertigated Sugarcane Production Environments for Bioethanol in the Midwest of Brazil." Agronomy 11, no. 8 (August 18, 2021): 1641. http://dx.doi.org/10.3390/agronomy11081641.
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Brazil is the world leader in the production and export of sugarcane derivatives, and its center-south region is the main producer. Fertigation with byproducts from bioethanol production can be adopted as a strategy to mitigate the soil physical deterioration resulting from the intensification of mechanized farming practices. The objective of this study was to evaluate the behavior of soil physical attributes under sugarcane cultivation in different crop cycles in fertigated areas in the midwest region of Brazil. The samples were collected in different Ferralsol layers (0.0–0.1, 0.1–0.2, 0.2–0.3, and 0.4–0.5 m) and fertigated crop cycles (first, third, fifth, seventh, and twelfth sugarcane cycles), as well as from native Cerrado vegetation (reference area), and the weight and volume relationships of the soil constituents and total soil were evaluated. Soil physical attributes are affected by sugarcane cultivation cycles and fertigation with vinasse. In the short term (third cycle), the results indicate deterioration of the physical attributes of the soil. However, throughout the cycles of sugarcane culture via fertigation (twelve cycles), the addition of vinasse leads to improvements in physical attributes and soil aggregation, promoting an increase in the longevity of the sugarcane crop. Therefore, the evaluation of the physical attributes of the soil in areas with vinasse application in different sugarcane cultivation cycles should be analyzed in areas of different regions, as this management practice indicates a high potential to increase the longevity of cultivation sugarcane, reducing production costs in the bioenergy sector.
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Buss, Ricardo N., Raimunda A. Silva, Glécio M. Siqueira, Jairo O. R. Leiva, Osmann C. C. Oliveira, and Victor L. França. "Spatial and multivariate analysis of soybean productivity and soil physical-chemical attributes." Revista Brasileira de Engenharia Agrícola e Ambiental 23, no. 6 (June 2019): 446–53. http://dx.doi.org/10.1590/1807-1929/agriambi.v23n6p446-453.
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ABSTRACT The objective of this study was to evaluate the spatial variability of soybean yield, carbon stock, and soil physical attributes using multivariate and geostatistical techniques. The attributes were determined in Oxisols samples with clayey and cohesive textures collected from the municipality of Mata Roma, Maranhão state, Brazil. In the study area, 70 sampling points were demarcated, and soybean yield and soil attributes were evaluated at soil depths of 0-0.20 and 0.20-0.40 m. Data were analysed using multivariate analyses (principal component analysis, PCA) and geostatistical tools. The mean soybean yield was 3,370 kg ha-1. The semivariogram of productivity, organic carbon (OC), and carbon stock (Cst) at the 0-0.20 m layer were adjusted to the spherical model. The PCA explained 73.21% of the variance and covariance structure between productivity and soil attributes at the 0-0.20 m layer [(PCA 1 (26.89%), PCA 2 (24.10%), and PCA 3 (22.22%)] and 68.64% at the 0.20-0.40 m layer [PCA 1 (31.95%), PCA 2 (22.83%), and PCA 3 (13.85%)]. The spatial variability maps of the PCA eigenvalue scores showed that it is possible to determine management zones using PCA 1 in the two studied depths; however, with different management strategies for each of the layers in this study.
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Cortez, Jorge W., Egas J. Armando, Anamari Viegas de A. Motomiya, Sonia A. Rodrigues, and Eduardo A. Gonçalves. "SOIL PHYSICAL ATTRIBUTES BEFORE AND AFTER MANAGEMENT UNDER SOWING FORWARD SPEED." Engenharia Agrícola 39, no. 5 (October 2019): 607–15. http://dx.doi.org/10.1590/1809-4430-eng.agric.v39n5p607-615/2019.
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Arcoverde, Sálvio N. S., Cristiano M. A. de Souza, Leidy Z. L. Rafull, Jorge W. Cortez, and Roberto C. Orlando. "SOYBEAN AGRONOMIC PERFORMANCE AND SOIL PHYSICAL ATTRIBUTES UNDER TRACTOR TRAFFIC INTENSITIES." Engenharia Agrícola 40, no. 1 (February 2020): 113–20. http://dx.doi.org/10.1590/1809-4430-eng.agric.v40n1p113-120/2020.
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Siqueira, Glecio Machado, Sidney Rosa Viera, Luiza Honora Pierre, and Celia Regina Grego. "SPATIAL VARIABILITY OF RUBBER TREE DENDROMETRICS CHARACTERISTICS AND SOIL PHYSICAL ATTRIBUTES." Journal of Geospatial Modelling 2, no. 2 (November 7, 2017): 32. http://dx.doi.org/10.22615/2526-1746-jgm-2.2-7856.
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Wanderson, Mendes Martins, Grillo Neves Leonarda, Lana Araújo Kelly, Fernandes Correa Adriel, Marques Zeviani Walmes, Montoani Silva Bruno, Grillo Neves Leonarda, Alexandre Santana Gilio Thiago, and Evaldo Serafim Milson. "Soil hydro-physical attributes under management practices for pineapple genotypes cultivation." African Journal of Agricultural Research 14, no. 12 (March 21, 2019): 652–58. http://dx.doi.org/10.5897/ajar2016.11452.
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Cucunubá-Melo, J. L., J. G. Álvarez-Herrera, and J. H. Camacho-Tamayo. "IDENTIFICATION OF AGRONOMIC MANAGEMENT UNITS BASED ON PHYSICAL ATTRIBUTES OF SOIL." Journal of soil science and plant nutrition 11, no. 1 (2011): 87–99. http://dx.doi.org/10.4067/s0718-95162011000100008.
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Afrasiabi, Fatemeh, Habib Khodaverdiloo, Farrokh Asadzadeh, and Martinus Th van Genuchten. "Comparison of alternative soil particle-size distribution models and their correlation with soil physical attributes." Journal of Hydrology and Hydromechanics 67, no. 2 (June 1, 2019): 179–90. http://dx.doi.org/10.2478/johh-2018-0009.
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Abstract Complete descriptions of the particle-size distribution (PSD) curve should provide more information about various soil properties as opposed to only the textural composition (sand, silt and clay (SSC) fractions). We evaluated the performance of 19 models describing PSD data of soils using a range of efficiency criteria. While different criteria produced different rankings of the models, six of the 19 models consistently performed the best. Mean errors of the six models were found to depend on the particle diameter, with larger error percentages occurring in the smaller size range. Neither SSC nor the geometric mean diameter and its standard deviation correlated significantly with the saturated hydraulic conductivity (Kfs); however, the parameters of several PSD models showed significant correlation with Kfs. Porosity, mean weight diameter of the aggregates, and bulk density also showed significant correlations with PSD model parameters. Results of this study are promising for developing more accurate pedotransfer functions.
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Castioni, Guilherme Adalberto Ferreira, Zigomar Menezes de Souza, Aline Azevedo Nazário, Bernardo Melo Montes Nogueira Borges, José Luiz Rodrigues Torres, Marcelo Rodrigues Soares Dayron, and Milton César Costa Campos. "Variability of physical attributes in tropical weathered soil cultivated with irrigated beans (Phaseolus vulgaris L.)." Australian Journal of Crop Science, no. 13(05) 2019 (May 20, 2019): 656–61. http://dx.doi.org/10.21475/ajcs.19.13.05.p1115.
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Soil physical attributes are affected by several events. The ability to identify the variation of those attributes can be used to decide the best crop management. Although it is known that smaller grids are more representative, predicting the least number of points while maintaining accuracy is a tool that might reflect a gain in yield and time. The aims of this study were to evaluate the spatial physical variability and to define the minimum sampling density in a tropical Typic Haplustults soil using a scaled semivariogram in a central pivot area with pinto bean (Phaseolus vulgaris L.) after the eighth bean harvest in Cristalina, Goias State. Soil samples were collected at a regular grid of 10-m intervals, totaling 180 points, and at depths of 0.00–0.10 m, 0.10–0.20 m, and 0.20–0.30 m to determine total sand content (TS), silt (SIL), clay (CL), water-dispersed clay (WDC), mean weight diameter of soil aggregates (MWD), soil penetration resistance (PR), soil macroporosity (Ma), soil microporosity (Mi), and soil bulk density (BD). The results demonstrated that management promoted superficial soil compaction with increasing BD and Mi and decreasing Ma and TP. The scaled semivariogram demonstrated similarity between attributes in the three studied soil layers, evidencing strong spatial dependency. The sample density showed a strong influence of WDC in the irrigated soil properties. Adoption of a scaled semivariogram is a strategy that can be used to determine a minimum number of points that represents the spatial variability of soil physical attributes and to assist the best management in irrigated soils.
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Farias, Maryzélia Furtado de, Carlos Eduardo Linhares Feitosa, Khalil De Menezes Rodrigues, Liliane Carvalho Teixeira, Mariléia Barros Furtado, and Luisa Julieth Parra-Serrano. "Impact of Management on the Physical Attributes of a Dystrophic Yellow Latosol." Journal of Agricultural Science 9, no. 5 (April 12, 2017): 217. http://dx.doi.org/10.5539/jas.v9n5p217.
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Soil use and management systems aim to create conditions that are favorable to crop growth. The hypothesis is that areas subject to intensive use of agricultural machinery and animal trampling tend to have a soil structure that is altered by aggregate fragmentation, which causes soil compaction and consequently decreases the soil’s physical and hydraulic properties. The aim of this study was to assess and compare the physical and hydraulic parameters of a dystrophic yellow latosol in an area of Cerrado in the municipality of Chapadinha, Maranhão, Brazil under different use and management systems. The following five use and management systems were studied with five replicates: native forest (control), slash-and-burn agriculture, grassland, no-till crop production and conventional tillage. Data analysis was performed using a completely randomized experimental design. The soil’s density, macroporosity, microporosity, total porosity, hydraulic conductivity, infiltration, water retention curve, penetration resistance and Soil quality assessment index (S index) were assessed for all management systems. The soil use and management systems were found to have a significant effect on the penetration resistance and the water infiltration rate. The native forest and slash-and-burn agriculture areas provided the highest soil water infiltration rates and the lowest soil penetration resistance. A multivariate analysis identified the variables associated with each soil use and management system. The slash-and-burn agriculture area had the highest S index, which means it provided soil of the best physical quality.
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Roehrs, Simone Andreia, Aracéli Ciotti de Marins, Deonir Secco, Rogério Luís Rizzi, Luiz Antônio Zanão Júnior, Pablo Chang, Claudia Borgmann, Bruna de Villa, Lucas da Silveira, and Luciene Kazue Tokura. "Spatial distribution of physical attributes of a clayey Latosol under different management systems." DECEMBER 2020, no. 14(12):2020 (December 10, 2020): 1883–88. http://dx.doi.org/10.21475/ajcs.20.14.12.2650.
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The use and management of the soil cause occasional changes in its physical properties; thus, altering its spatial variability. This work aimed to show the spatial distribution of physical attributes of a clay latosol under different management systems, through thematic maps of spatial distribution for values of these attributes. The experimental area consisted of three treatments: scarified no-tillage at 0.3 m depth (T1), no-tillage with 3 t ha-1 of plaster applied to the surface (T2) and; the control as traditional no-tillage system (T3). The attributes such as density, macroporosity, and microporosity in three soil layers were evaluated: 0-0.1; 0.1-0.2; and 0.2-0.3 m. The analysis of the experimental results indicates that all physical attributes presented spatial dependence between the data, with higher density values (values ranged from 0.95 to 1.37 Mg m3) and lower macroporosity in areas with T1 (SPD with scarification) and T2 (SPD gypsum) management systems. However, in all treatments, the Macro values presented a volume above 10.51%, which is above the limit value for good aeration and water movement in the soil. Treatment T3 (traditional SPD) showed favorable physical soil conditions, even after compaction
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Soares, Jorge Luís Nascimento, Carlos Roberto Espindola, and Walcylene Lacerda Matos Pereira. "Physical properties of soils under intensive agricultural management." Scientia Agricola 62, no. 2 (April 2005): 165–72. http://dx.doi.org/10.1590/s0103-90162005000200012.
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Pedologic alterations after long-term sugar cane (Saccharum officinarum) cropping cycles under traditional soil management systems were studied on a farm in Bariri, SP, Brazil. A toposequence was established to evaluate the effects of the soil position in the relief in changing soil physical attributes. Morphological field descriptions and laboratory analyses were carried out on vertical profiles of the upper, middle and lower thirds of a Typic Haplorthox slope. Soil bulk density and macroporosity changed along the toposequence reflecting on soil hydrodynamics, especially in the lower slope parts. At sites with high clay levels, empty spaces were filled forming block shaped structures together with the micro-aggregate structure. The intensive cultivation induced the greatest soil structure alterations, even at the deepest layers. The study pointed out the importance of performing detailed morphological observations in vertical profiles, due to the great variation on pedological attributes over short distances. Compacted soil sections were observed side-by-side with desaggregated mottles in the same soil profile. This fact evidenced that both vertical (in each profile) and horizontal gradients (along a toposequence) need to be considered in studies of time sequence variation of pedological parameters.
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Araújo, Fernando Silva, Adeodato Ari Cavalcante Salviano, Luiz Fernando Carvalho Leite, Zigomar Menezes de Souza, and Allan Charlles Mendes de Sousa. "Physical quality of a yellow latossol under integrated crop-livestock system." Revista Brasileira de Ciência do Solo 34, no. 3 (June 2010): 717–23. http://dx.doi.org/10.1590/s0100-06832010000300013.
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Soil physical quality is essential to global sustainability of agroecosystems, once it is related to processes that are essential to agricultural crop development. This study aimed to evaluate physical attributes of a Yellow Latossol under different management systems in the savanna area in the state of Piaui. This study was developed in Uruçuí southwest of the state of Piauí. Three systems of soil management were studied: an area under conventional tillage (CT) with disk plowi and heavy harrow and soybean crop; an area under no-tillage with soybean-maize rotation and millet as cover crop (NT + M); two areas under Integrated Crop-Livestock System, with five-month pasture grazing and soybean cultivation and then continuous pasture grazing (ICL + S and ICL + P, respectively). Also, an area under Native Forest (NF) was studied. The soil depths studied were 0.00-0.05, 0.05-0.10 and 0.10-0.20 m. Soil bulk density, as well as porosity and stability of soil aggregates were analyzed as physical attributes. Anthropic action has changed the soil physical attributes, in depth, in most systems studied, in comparison to NF. In the 0.00 to 0.05 m depth, ICL + P showed higher soil bulk density value. As to macroporosity, there was no difference between the management systems studied and NF. The management systems studied changed the soil structure, having, as a result, a small proportion of soil in great aggregate classes (MWD). Converting native forest into agricultural production systems changes the soil physical quality. The Integrated Crop-Livestock System did not promote the improvement in soil physical quality.
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Silva, Antonio Carlos da, Jeane Cruz Portela, Rafael Oliveira Batista, Rutilene Rodrigues da Cunha, Joaquim Emanuel Fernandes Gondim, Luiz Eduardo Vieira de Arruda, and José Francismar de Medeiros. "Soil Water Retention in the Semiarid Region of Brazil." Journal of Agricultural Science 10, no. 9 (August 13, 2018): 105. http://dx.doi.org/10.5539/jas.v10n9p105.
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From the physics point of view, soil structure is a dynamic attribute that is affected by genetic conditions and anthropogenic changes and requires an integrated approach. Soil water retention curve is one of the main tools used in soil structure evaluations. The objective of this work was to evaluate the structural and chemical attributes of soils of different classes and agroecosystems in the Terra de Esperança Settlement (Governador Dix Sept Rosado, Rio Grande do Norte, Brazil) to distinguish these environments. Disturbed and undisturbed soil samples were collected in horizons of 10 soil profiles of the soil classes: Cambissolo Háplico (Haplustepts), Latossolo Vermelho-Amarelo (Eutrustox), Chernossolo Rêndzico (Calciustolls), and Neossolo Flúvico (Usticfluvents). The soil physical attributes evaluated were granulometry, soil density, total porosity, aeration porosity, macroporosity, microporosity, field capacity, permanent wilting point, available water, and water retention curve. The results were expressed in averages of four replicates per horizon (in laboratory) by multivariate analysis, which detected the most sensitive attributes for the distinction of the environments. The soil physical attributes of the different classes and its inorganic fractions, especially silt and clay, were determinant to distinguish the environments; they affected the microporosity; aeration porosity; and available water. The source material of the Chernossolo Rêndzico, which is rich in calcium and magnesium, affected its physical attributes, characterized by the predominance of the silt fraction. Clay was the determinant fraction of the Cambissolo Háplico, and Neossolo Flúvico; and the sand fraction on the surface layer, and clay fraction in the Bw horizon were determinant of the Latossolo Vermelho-Amarelo. The more expressive physical attributes were soil density, sand content, macroporosity (Latossolo Vermelho-Amarelo), microporosity, field capacity, available water, permanent wilting point, total organic carbon, mass-based moisture, volume-based moisture, clay, aeration porosity (Cambissolo Háplico, and Neossolo Flúvico), and silt (Chernossolo Rêndzico).