The Experts below are selected from a list of 2019 Experts worldwide ranked by ideXlab platform
Itzhak Benenson - One of the best experts on this subject based on the ideXlab platform.
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degradation of soil fertility following cycles of cotton cereal cultivation in mali west africa a first approximation to the problem
Soil & Tillage Research, 2010Co-Authors: Giora J Kidron, Arnon Karnieli, Itzhak BenensonAbstract:Abstract Common agricultural practice in West Africa involves alternating crop cultivation for 10–12 years and thereafter leaving the field to rest (fallow) for 10–15 years. With increasing population pressure and growing demand for food on the one hand, and the lack of unexploited lands on the other, Soils undergo fast degradation. In an attempt to predict soil degradation, 12 fields were sampled around Kita, Mali. Seven of these fields were under cultivation whereas the remaining fields were fallow or Virgin Soils. The soil pH, electrical conductivity, N–NO 3 , N–NH 4 , P, K, and the soil organic matter (SOM) were determined. Of all variables, only nitrogen and SOM showed significant linear relationship with cotton lint at the cultivated fields, with SOM being the only variable showing a clear threshold (of 18 t/ha) that distinguishes between fertile and infertile fields. Based on field observations a simple model of the family agricultural land use is presented, aiming to provide a link between agriculture practice and soil degradation. The model demonstrates that the current practices of cultivation and fertilization will result in a slow but inevitable decrease of SOM, with SOM reaching, in 25–35 years, a critical level, below which cotton growth will no longer be economical. We thus conclude that the current practice of cultivation is inefficient and a new cultivation practice, which accounts for the cardinal role of SOM should be adopted.
Hamid Reza Memarian - One of the best experts on this subject based on the ideXlab platform.
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effect of land use change on soil fertility characteristics within water stable aggregates of two cultivated Soils in northern iran
Land Use Policy, 2009Co-Authors: Mostafa Emadi, Majid Baghernejad, Hamid Reza MemarianAbstract:Abstract Forest and pastureland Soils in highland of northern Iran are being seriously degraded and destructed due to extensive agricultural activities. These land use changes are usually accompanied by decreasing in concentrations of soil organic carbon and nutrients and also deterioration of soil structure in these regions. However, studies on concentration of nutrients and carbohydrates in Soils suggest that the location of nutrients within aggregates of each size should be determined. This study was to evaluate the nutrient elements and carbohydrate distributions within water-stable aggregates (WSA) of Virgin forest and pasture lands under different land uses in Alborz maintain range, northern Iran. In September 2006, soil samples were collected from depths of 0–20 cm in Typic Haploxerolls Soils. The overall pattern indicated that the mean weight diameter (MWD) and WSA were greater in the Virgin pasture and forest Soils compared with the adjacent cultivated (ex-forest and ex-pasture) Soils and aggregates of >1.0 mm size were dominant in the Virgin Soils, whereas the cultivated Soils comprised aggregates of the size ≤0.5 mm. Distribution of organic carbon, nitrogen, phosphorus and carbohydrates within the WSA showed preferential enrichment of these parameters in the macroaggregate fraction (4.75–1.0 mm) for the Virgin Soils and microaggregate fraction (>0.25 mm) for the exposed Soils. Cultivation decreased the concentration of carbohydrates by 23.6% and 20.6% in ex-forest and ex-pasture lands, respectively. Average distribution of total exchangeable bases within WSA showed that the cultivation of forest and pasture Soils significantly led to reduce in these nutrient in the 4.75–2.0 mm fraction and increase in concentration of these exchangeable cations in
B.r. Tripathi - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Rice Growing and Adjacent Virgin Soils-I. Morphology, Properties, Genesis and Classification
Journal of the Indian Society of Soil Science, 1993Co-Authors: R.d. Gupta, B.r. TripathiAbstract:Three rice growing and two adjacent Virgin Soils from the north west Himalayas (Kangra district; HP) were studied/or their morphology, characteristics. genesis and classification. Although the former differs to some extent in morphology and clay contentfrom the latter both are similar in most of other soil properties. Chemically. all the profiles exhibit moderate development and are still in the pedogenic weathering stage.
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Characterization of Rice Growing and Adjacent Virgin Soils-II. Mineralogy of Sand, Silt and Clay Fractions
Journal of the Indian Society of Soil Science, 1993Co-Authors: R.d. Gupta, B.r. TripathiAbstract:Mineralogy of sand, silt and clay fraction in the selected horizons of rice growing and adjacent Virgin soil profiles from north-west Himalayan region (Kangra district, HP) does not show much difference. The light sand fraction is predominated by quartz, feldspars and muscovite mica and that of heavy sand by opaque minerals, zircon and tourmaline (⩾ 60%). Orthoclase, plagioclase, augite and hornblende are of weathered nature. Silt fraction contains mica, feldspars, quartz and chlorite. In the clay fractions, mica or illite are the dominant clay minerals followed by chlorite, kaolinite and mixed layers, as well as amorphous SiO2 and Al2O3. Mica is di-and trioctahedral in nature and chlorite is trioctahedral.
Daniel Eduardo Buschiazzo - One of the best experts on this subject based on the ideXlab platform.
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comparing adjacent cultivated and Virgin Soils in wind erosion affected environments can lead to errors in measuring soil degradation
Geoderma, 2016Co-Authors: Laura Antonela Iturri, Fernando Avecilla, Graciela Gloria Hevia, Daniel Eduardo BuschiazzoAbstract:Abstract Soil degradation has been frequently evaluated by comparing cultivated Soils with paired reference pedons. Evaluated were some physical and chemical properties of cultivated and reference Soils of a semiarid environment in a nine year period in order to evaluate possible changes in both management situations. Analyzed were seven degraded Soils of variable textures, which are cultivated since more than 50 years, and seven paired neighbor pedons placed in the less disturbed Caldenal savanna-like ecosystem of the central semiarid region of Argentina. Results indicated that soil properties of both, cultivated and reference Soils changed in this period. The driving factor of these changes was wind erosion, which produced a decrease in the proportion of the fine sized particles (silt and clay) in cultivated Soils due to deflation processes, and an increase in reference Soils due to the sedimentation of material transported from neighbor eroded Soils. Medium textured Soils (loamy sand) suffered the largest textural changes in agreement with more aggressive management practices that promoted wind erosion. The coarsest- (sandy) and the finest textured Soils (sandy loam) did not show textural changes because they were managed with more conservative practices and were more resistant against erosion than medium textured Soils. Under the moist conditions of the studied period contents of total carbon (OC), total carbohydrates (CHt) and nitrogen (N) increased by 50% in most reference Soils. Cultivated Soils presented 64% less OC, CHt and N than reference Soils, but these differences were produced mainly by increases in reference Soils rather than by decreases in cultivated Soils. The C/N and C/CHt ratios decreased mainly in medium textured cultivated Soils. The wind erodible fraction (EF, the
Sabit Erşahin - One of the best experts on this subject based on the ideXlab platform.
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Saturated Hydraulic Conductivity Variation in Cultivated and Virgin Soils
Turkish Journal of Agriculture and Forestry, 2006Co-Authors: Tekin Öztekin, Sabit ErşahinAbstract:Variation of saturated hydraulic conductivity (K s ) values of Soils under diverse management practices may be needed to determine the required sample number, sample size, and chose suitable sample scheme for characterize the K s values used in water flow and solute transport modelling studies. The purpose of this study was to examine the variability in K s and try to understand some part of the determinism of this variability in Virgin and adjacent cultivated field using 36 undisturbed soil samples from each location with 0.5-m grid space. K s was measured with 100 cm 3 undisturbed soil cores in laboratory using falling or constant head methods. The results showed that variability of In (K s ) values (variance = 10.3) at the cultivated site was 2.5 times greater than that (variance = 2.5) at the Virgin site. Furthermore, significant K s differences exist between cultivated sample locations and within the rows of each cultivated location. Greater variations occurred in two cultivated locations may be attributed to compaction by traffic and soil tillage resulting in heterogeneous bulk density over the study area.
