The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Eric F Lambin - One of the best experts on this subject based on the ideXlab platform.
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Monitoring degradation in arid and semi-arid forests and woodlands: The case of the argan woodlands (Morocco)
Applied Geography, 2012Co-Authors: Yann Le Polain De Waroux, Eric F LambinAbstract:Arid and semi-arid forests and woodlands (hereafter called «dryland forests»), in spite of their ecological and social importance, have received little attention in land change studies. Growing evidence shows that these forests have been receding at very high rates in many places, suggesting a need for a better understanding of the processes and causes of dryland forest degradation. Changes in the extent of dryland forests are debated in part because estimates of forest and woodland areas in drylands are uncertain. Causal explanations of the degradation tend to draw on the literature on desertification and tropical deforestation, and to emphasize either local or remote, and either social or biophysical drivers. This study contributes to a better understanding of dryland forest degradation as a basis for conservation policies. Firstly, we argue that monitoring arid and semi-arid forests and woodlands using area estimates may lead to an underestimation of the severity of change because tree density change often exceeds area change. Secondly, we argue that the analysis of degradation processes in these multifunctional landscapes should integrate both local and remote, and both social and biophysical factors. We use a case study of degradation in the argania woodlands in semi-arid to arid Southwest Morocco to test these two claims. We used gridded tree counts on aerial photographs and satellite images to estimate forest change between 1970 and 2007, and we tested several possible causes of change on the basis of original socio-economic field surveys and climatic and topographic data. We found that forest density declined by 44.5% during this period, a figure that is significantly underestimated if forest area change is used as a measure of degradation. Increasing aridity and, to a lesser extent, fuelwood extraction were related to forest decline. No effect of grazing by local livestock was found. © 2011 Elsevier Ltd.
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global desertification building a science for dryland development
Science, 2007Co-Authors: James F. Reynolds, Simon P.j. Batterbury, Hadi Dowlatabadi, Michael Mortimore, B. L. Turner, Thomas E. Downing, Mark Stafford D Smith, Roberto Fernandez, Eric F Lambin, Jeffrey E. HerrickAbstract:In this millennium, global drylands face a myriad of problems that present tough research, management, and policy challenges. Recent advances in dryland development, however, together with the integrative approaches of global change and sustainability science, suggest that concerns about land degradation, poverty, safeguarding biodiversity, and protecting the culture of 2.5 billion people can be confronted with renewed optimism. We review recent lessons about the functioning of dryland ecosystems and the livelihood systems of their human residents and introduce a new synthetic framework, the Drylands Development Paradigm (DDP). The DDP, supported by a growing and well-documented set of tools for policy and management action, helps navigate the inherent complexity of desertification and dryland development, identifying and synthesizing those factors important to research, management, and policy communities.
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Ecology: Global desertification: Building a science for dryland development
Science, 2007Co-Authors: James F. Reynolds, D. Mark Stafford Smith, Simon P.j. Batterbury, Roberto J. Fernández, Hadi Dowlatabadi, Michael Mortimore, B. L. Turner, Thomas E. Downing, Eric F Lambin, Jeffrey E. HerrickAbstract:In this millennium, global drylands face a myriad of problems that present tough research, management, and policy challenges. Recent advances in dryland development, however, together with the integrative approaches of global change and sustainability science, suggest that concerns about land degradation, poverty, safeguarding biodiversity, and protecting the culture of 2.5 billion people can be confronted with renewed optimism. We review recent lessons about the functioning of dryland ecosystems and the livelihood systems of their human residents and introduce a new synthetic framework, the Drylands Development Paradigm (DDP). The DDP, supported by a growing and well-documented set of tools for policy and management action, helps navigate the inherent complexity of desertification and dryland development, identifying and synthesizing those factors important to research, management, and policy communities.
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dynamic causal patterns of desertification
BioScience, 2004Co-Authors: Helmut J Geist, Eric F LambinAbstract:Using a meta-analytical research design, we analyzed subnational case studies (n = 132) on the causes of dryland degradation, also referred to as desertification, to determine whether the proximate causes and underlying driving forces fall into any pattern and to identify mediating factors, feedback mechanisms, cross-scalar dynamics, and typical pathways of dryland ecosystem change. Our results show that desertification is driven by a limited suite of recurrent core variables, of which the most prominent at the underlying level are climatic factors, economic factors, institutions, national policies, population growth, and remote influences. At the proximate level, these factors drive cropland expansion, overgrazing, and infrastructure extension. Identifiable regional patterns of synergies among causal factors, in combination with feedback mechanisms and regional land-use and environmental histories, make up specific pathways of land change for each region and time period. Understanding these pathways is crucial for appropriate policy interventions, which have to be fine-tuned to the region-specific dynamic patterns associated with desertification.
Xiaobin Wang - One of the best experts on this subject based on the ideXlab platform.
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Conservation tillage for dryland farming in China
2020Co-Authors: J. Ke, Xiaobin Wang, Willem B. Hoogmoed, Oene Oenema, U.d. PerdokAbstract:Dryland regions account for above 70% of total nation's farmland in China. These dryland are vital contributors to the total national production of grains, cash crops and animal products. However, the development of dryland farming is constrained by harsh climate, bad economic situation and poor knowledge on land management. Even though the conservation tillage research and application in dryland regions of China has been actively promoted since 1980s, the conventional tillage is still prevalent in these regions. The bottleneck for sustainable agriculture in China is still the lack of knowledge amongst both farmers and extension organizations about practices pertained to sustainable land management. In this paper, we analyzed the regional characteristics and regional adaptation of conservation tillage systems in China’s dryland regions; reviewed the research conducted on conservation tillage in China, and discussed the problems faced with the introduction and application of conservation tillage practices in order to gain a better perception of the role of soil conservation tillage and promote application of practical technologies for dryland farming systems in China. To ensure a wider adoption of conservation tillage, several actions should be strengthened. These include: 1) strengthen the on-the ground, pilot field activates and further intensify the demonstration 2) optimize information, instruction, support and guidance of the farmer 3) enact specific legislation for the development, adoption and implementation of conservation agriculture.
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developments in conservation tillage in rainfed regions of north china
Soil & Tillage Research, 2007Co-Authors: Xiaobin Wang, Willem B. Hoogmoed, Oene Oenema, U.d. PerdokAbstract:Abstract Dryland regions in northern China account for over 50% of the nation's total area, where farming development is constrained by adverse weather, topography and water resource conditions, low fertility soils, and poor soil management. Conservation tillage research and application in dryland regions of northern China has been developed since the 1970s. Demonstration and extension of conservation tillage practices is actively stimulated by the Chinese government since 2002, following the recognition of the increased rate of degradation of the environment due to erosion and water shortage in North China. This paper reviews the research conducted on conservation tillage in dryland regions of northern China, and discusses the problems faced with the introduction and application of conservation tillage practices. Most of the studies reported have shown positive results of soil and water conservation tillage practices. These practices generally involve a reduction in the number and intensity of operations compared to conventional tillage, with direct sowing or no-till as the strongest reduction. Crop yields and water use efficiency have increased (with up to 35%) following the implementation of reduced tillage practices. Under no-till, crop yields are equivalent to or higher than those from conventional tillage methods, especially in dry years. However, during wet years yields tend to be lower (10–15%) with no-till. Other benefits are an increased fallow water storage and reductions in water losses by evaporation. In order to fully exploit the advantages of conservation tillage, systems have to be adapted to regional characteristics. Farmers’ adoption of conservation tillage is still limited.
U.d. Perdok - One of the best experts on this subject based on the ideXlab platform.
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Conservation tillage for dryland farming in China
2020Co-Authors: J. Ke, Xiaobin Wang, Willem B. Hoogmoed, Oene Oenema, U.d. PerdokAbstract:Dryland regions account for above 70% of total nation's farmland in China. These dryland are vital contributors to the total national production of grains, cash crops and animal products. However, the development of dryland farming is constrained by harsh climate, bad economic situation and poor knowledge on land management. Even though the conservation tillage research and application in dryland regions of China has been actively promoted since 1980s, the conventional tillage is still prevalent in these regions. The bottleneck for sustainable agriculture in China is still the lack of knowledge amongst both farmers and extension organizations about practices pertained to sustainable land management. In this paper, we analyzed the regional characteristics and regional adaptation of conservation tillage systems in China’s dryland regions; reviewed the research conducted on conservation tillage in China, and discussed the problems faced with the introduction and application of conservation tillage practices in order to gain a better perception of the role of soil conservation tillage and promote application of practical technologies for dryland farming systems in China. To ensure a wider adoption of conservation tillage, several actions should be strengthened. These include: 1) strengthen the on-the ground, pilot field activates and further intensify the demonstration 2) optimize information, instruction, support and guidance of the farmer 3) enact specific legislation for the development, adoption and implementation of conservation agriculture.
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developments in conservation tillage in rainfed regions of north china
Soil & Tillage Research, 2007Co-Authors: Xiaobin Wang, Willem B. Hoogmoed, Oene Oenema, U.d. PerdokAbstract:Abstract Dryland regions in northern China account for over 50% of the nation's total area, where farming development is constrained by adverse weather, topography and water resource conditions, low fertility soils, and poor soil management. Conservation tillage research and application in dryland regions of northern China has been developed since the 1970s. Demonstration and extension of conservation tillage practices is actively stimulated by the Chinese government since 2002, following the recognition of the increased rate of degradation of the environment due to erosion and water shortage in North China. This paper reviews the research conducted on conservation tillage in dryland regions of northern China, and discusses the problems faced with the introduction and application of conservation tillage practices. Most of the studies reported have shown positive results of soil and water conservation tillage practices. These practices generally involve a reduction in the number and intensity of operations compared to conventional tillage, with direct sowing or no-till as the strongest reduction. Crop yields and water use efficiency have increased (with up to 35%) following the implementation of reduced tillage practices. Under no-till, crop yields are equivalent to or higher than those from conventional tillage methods, especially in dry years. However, during wet years yields tend to be lower (10–15%) with no-till. Other benefits are an increased fallow water storage and reductions in water losses by evaporation. In order to fully exploit the advantages of conservation tillage, systems have to be adapted to regional characteristics. Farmers’ adoption of conservation tillage is still limited.
Upendra M Sainju - One of the best experts on this subject based on the ideXlab platform.
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particulate and active soil nitrogen fractions are reduced by sheep grazing in dryland cropping systems
Nutrient Cycling in Agroecosystems, 2014Co-Authors: Upendra M Sainju, Joy L Barsotti, Andrew W Lenssen, P G HatfieldAbstract:Sheep (Ovis aries L.) grazing, a cost- effective method of weed control compared to herbi- cide application and tillage, may influence N cycling by consuming crop residue and weeds and returning N through feces and urine to the soil. The objective of this experiment was to evaluate the effect of sheep grazing compared to tillage and herbicide application for weed control on soil particulate and active soil N fractions in dryland cropping systems. Our hypothesis was that sheep grazing used for weed control would increase particulate and active soil N fractions com- pared to tillage and herbicide application. Soil samples collected at the 0-30 cm depth from a Blackmore silt loam were analyzed for particulate organic N (PON), microbial biomass N (MBN), and potential N miner- alization (PNM) under dryland cropping systems from 2009 to 2011 in southwestern Montana, USA.
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effects of tillage on microbial populations associated to soil aggregation in dryland spring wheat system
European Journal of Soil Biology, 2010Co-Authors: T Caesartonthat, Upendra M Sainju, Andy W Lenssen, Anthony J Caesar, John F GaskinAbstract:Abstract Tillage may influence the microbial populations involved in soil aggregation. We evaluated the effects of no till (NT) and conventional tillage (CT, tillage depth about 7 cm) continuous spring wheat system on culturable heterotrophic bacterial communities predominant in microaggregates (0.25–0.05 mm) and on soil-aggregating basidiomycete fungi in aggregate-size classes (4.75–2.00, 2.00–0.25, and 0.25–0.05 mm) at 0–20 cm depth of a Williams loam (fine-loamy, mixed, Typic Argiustolls) in dryland Montana, USA. Enzyme-linked immunosorbent assay used to quantify antigenic response to basidiomycete cell walls, was higher in NT than in CT in 4.75–2.00 mm size class in 2007 and higher in all classes and years at 0–5 cm depth, but was not different between tillage, years, and classes at 5–20 cm. The culturable bacteria from microaggregates were subjected to a soil sedimentation assay to determine their soil binding capability. The proportion of isolates which can function as soil aggregators was higher in NT than in CT at 0–5 cm but was not different at 5–20 cm. Our results provide a first insight into the beneficial effects of dryland NT compared to CT in reducing soil disturbance and residue incorporation and enriching the proportion of microorganisms responsible for aggregation, especially at the soil surface.
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cover crop effect on soil carbon fractions under conservation tillage cotton
Soil & Tillage Research, 2007Co-Authors: Upendra M Sainju, Harry H Schomberg, Bharat P Singh, Wayne F Whitehead, Glynn P Tillman, Sharon L LachnichtweyersAbstract:Cover crops may influence soil carbon (C) sequestration and microbial biomass and activities by providing additional residue C to soil. We examined the influence of legume [crimson clover (Trifolium incarnatum L.)], nonlegume [rye (Secale cereale L.)], blend [a mixture of legumes containing balansa clover (Trifolium michelianum Savi), hairy vetch (Vicia villosa Roth), and crimson clover], and rye + blend mixture cover cropson soil C fractions at the0‐150 mmdepth from 2001 to 2003. Active fractions of soil C includedpotentialCmineralization(PCM)andmicrobialbiomassC(MBC)andslowfraction assoilorganicC(SOC).Experiments were conducted in Dothan sandy loam (fine-loamy, kaolinitic, thermic, Plinthic Kandiudults) under dryland cotton (Gossypium hirsutum L.) in central Georgia and in Tifton loamy sand (fine-loamy, siliceous, thermic, Plinthic Kandiudults) under irrigated cotton in southern Georgia, USA. Both dryland and irrigated cotton were planted in strip tillage system where planting rows were
Joseph G Benjamin - One of the best experts on this subject based on the ideXlab platform.
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the variable response of dryland corn yield to soil water content at planting
Agricultural Water Management, 2009Co-Authors: David C Nielsen, Merle F Vigil, Joseph G BenjaminAbstract:Farmers in the central Great Plains want to diversify crop rotations from the traditional monoculture system of winter wheat-fallow. Corn (Zea mays L.) could work well as a rotation crop, but inputs are expensive and farmers would like to know the chances of producing a certain yield before investing in seed, fertilizer, herbicides, etc. Information on the yield response of corn to available soil water at planting could help guide the crop choice decision regarding corn. This study was conducted to determine if a predictive relationship exists between dryland corn yield and available soil water at planting time and, if such a relationship exists, to use it to assess the risk in obtaining profitable yields. Yield and soil water data from 10 years of a dryland crop rotation study at Akron, CO were analyzed by linear regression to determine predictive relationships. The yield-soil water content production function was highly variable, with values ranging from 0.0 to 67.3 kg ha-1 per mm of available soil water in the 0 to 1.8 m soil profile at planting. The differences in yield response to soil water were related to the amount and timing of precipitation that fell during the corn growing season. Because dryland corn yield is highly dependent on precipitation during reproductive and grain-filling stages, soil water content at corn planting cannot be used alone to reliably determine whether corn should be planted in a flexible rotational system. The predictive relationships developed in this study indicate that under typical amounts of available soil water at corn planting, profitable corn production under dryland conditions is a risky and speculative activity in the central Great Plains of the United States.
