Modeling organic carbon dynamics under no-tillage and plowed systems in tropical soils of Brazil using CQESTR.

Made available in DSpace on 2015-01-22T09:05:40Z (GMT). No. of bitstreams: 1 dinamica.carbono.solo.STR.LFernando.pdf: 594077 bytes, checksum: 299ff554c4e53c9c6d24e3cf7ab1f228 (MD5) Previous issue date: 2010-02-2

Biogeochemical research priorities for sustainable biofuel and bioenergy feedstock production in the Americas.

Rapid expansion in biomass production for biofuels and bioenergy in the Americas is increasing demand on the ecosystem resources required to sustain soil and site productivity. We review the current state of knowledge and highlight gaps in research on biogeochemical processes and ecosystem sustainability related to biomass production. Biomass production systems incrementally remove greater quantities of organic matter, which in turn affects soil organic matter and associated carbon and nutrient storage (and hence long-term soil productivity) and off-site impacts. While these consequences have been extensively studied for some crops and sites, the ongoing and impending impacts of biomass removal require management strategies for ensuring that soil properties and functions are sustained for all combinations of crops, soils, sites, climates, and management systems, and that impacts of biomass management (including off-site impacts) are environmentally acceptable. In a changing global environment, knowledge of cumulative impacts will also become increasingly important. Long-term experiments are essential for key crops, soils, and management systems because short-term results do not necessarily reflect long-term impacts, although improved modeling capability may help to predict these impacts. Identification and validation of soil sustainability indicators for both site prescriptions and spatial applications would better inform commercial and policy decisions. In an increasingly interrelated but constrained global context, researchers should engage across inter-disciplinary, inter-agency, and international lines to better ensure the long-term soil productivity across a range of scales, from site to landscape.Fil: Gollany, Hero T. USDA. Agricultural Research Service. Columbia Plateau Conservation Research Center; Estados UnidosFil: Titus, Brian D. Pacific Forestry Centre. Canadian Forest Service. Natural Resources Canada; CanadáFil: Scott, Andrew USDA Forest Service. Agricultural Research Center. Southern Research Station; Estados UnicosFil: Asbjornsen, Heidi. University of New Hampshire. Institute for Earth, Oceans and Space. Department of Natural Resources and the Environment and the Earth Systems Research Center; Estados UnidosFil: Resh, Sigrid C. Michigan Technological University. School of Forest Resources and Environmental Science; Estados UnidosFil: Chimner, Rodney Allen. Michigan Technological University. School of Forest Resources and Environmental Science; Estados UnidosFil: Kaczmarek, Donald J. Oregon Department of Forestry; Estados UnidosFil: Leite, Luiz F. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); BrasilFil: Ferreira, Ana C. Climate Change Adaptation Consultant; BrasilFil: Rod, Kenton A. Washington State University. School of the Environment; Estados UnidosFil: Hilbert, Jorge Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Ingeniería Rural; ArgentinaFil: Galdos, Marcelo. Brazilian Center for Research in Energy and Materials (CNPEM). Brazilian Bioethanol Science and Technology Laboratory (CTBE); BrasilFil: Cisz, Michelle E. Michigan Technological University. School of Forest Resources and Environmental Science; Estados Unido

Comparison of Runoff, Soil Erosion, and Winter Wheat Yields from No-Till and Inversion Tillage Production Systems in Northeastern Oregon

Conservation tillage systems that reduce soil erosion and maintain or increase soil carbon offer long-term benefits for producers in the inland Pacific Northwestern United States but could result in reduced grain yields due to increased pressure from weeds, disease, and insect pests. Our objective was to compare runoff, soil erosion, and crop yields from a conventional tillage, wheat-fallow two-year rotation and a no-till four-year rotation. The experiment was undertaken within a small watershed to provide results that would be repre¬sentative of conservation effectiveness at the field scale. Two neighboring drainages, 5.8 and 10.7 ha (14 and 26 ac), in the 340 mm y-1 (13.4 in yr-1) precipitation zone of northeastern Oregon, were instrumented to record rainfall, runoff, and erosion over a four-year period (2001 through 2004). One drainage was cropped to a winter wheat–fallow rotation and received inversion tillage (tillage fallow). The second drainage was cropped in a four-year no-till rotation: winter wheat–chemical fallow–winter wheat–chickpea (no-till fallow). We recorded 13 runoff events from the inversion tillage system and 3 from the no-till system. Total runoff and erosion values from inversion tillage drainage were 5.1 mm (0.20 in) and 0.42 Mg ha-1 (0.19 tn ac-1) versus 0.7 mm (0.03 in) and 0.01 Mg ha-1 (-1) from no-till drainage. The no-till rotation was substantially more effective in conserving soil and water in this field-scale comparison. Soil erosion observed in this research is a fraction of that reported for similar tillage practices outside of the Pacific Northwestern. Mean wheat yields did not significantly differ between inversion tillage and no-till treatments despite intensify¬ing the rotation by replacing one year of fallow with a chickpea crop in the four-year rota¬tion. Because of high year-to-year variability in yield and limited sample size, more study is needed to compare winter wheat yields in no-till production systems with inversion tillage. The no-till cropping system was more effective in reducing runoff and soil erosion and provides producers with an ability to protect soil and water resources in the dryland Pacific Northwest

Modeling organic carbon dynamics under no-tillage and plowed systems in tropical soils of Brazil using CQESTR.

Made available in DSpace on 2015-01-22T09:05:40Z (GMT). No. of bitstreams: 1 dinamica.carbono.solo.STR.LFernando.pdf: 594077 bytes, checksum: 299ff554c4e53c9c6d24e3cf7ab1f228 (MD5) Previous issue date: 2010-02-25200

Applications of laser-induced breakdown spectroscopy for soil analysis, part I: Review of fundamentals and chemical and physical properties.

Made available in DSpace on 2020-03-11T18:05:46Z (GMT). No. of bitstreams: 1 PApplicationsoflaserinducedbreakdownspectroscopyforsoil....pdf: 2229753 bytes, checksum: bfc9d3c4234b896a4f94b96d69cb9296 (MD5) Previous issue date: 2019bitstream/item/207789/1/P-Applications-of-laser-induced-breakdown-spectroscopy-for-soil....pd