Location: Integrated Cropping Systems Research2013 Annual Report
1a. Objectives (from AD-416):
1. Determine the effects of tillage, corn residue removal, cover crop, and crop rotation on soil physical, chemical, and biological properties including greenhouse gas and soil carbon dynamics in conventional and organic agricultural production systems. Contribute to multi-location projects including Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet) and Renewable Energy Assessment Project (REAP). 2. Assess soil-landscape rehabilitation (movement of soil from areas of net accumulation to areas of net soil loss) as a means of improving soil characteristics, soil productivity, farm profitability, pesticide persistence and mobility, and soil erosion. 3. Develop crop rotation, soil nutrient cycling, corn residue removal and pest management practices that improve farming efficiency (increase unit output/unit input), and manage soils in a holistic approach to improve crop yield and quality while maintaining or reducing production inputs.
1b. Approach (from AD-416):
The need to produce ever-increasing amounts of food, feed, fiber, and biofuel feedstocks for a growing world population, increased production costs, and fluctuating commodity prices are difficult challenges faced by our customers. Additionally, potential global climate effects on the local environment, degradation of soil resources, and depletion of non-renewable resources (e.g., oil and phosphorus fertilizers) are important concerns of farmers in our region and throughout the U.S. To answer these challenges and concerns, we are conducting research to optimize soil, crop and pest management practices and to synthesize them into integrated production systems that are economically sound, environmentally sustainable, and provide maximized production efficiency. This interdisciplinary project aims to define, for the unique conditions of the northwest Corn Belt and northern Great Plains, the relationships between soil, crop, and pest management and the conservation of the soil resource. This work is essential for the development of integrated production systems and sustainable agriculture in this region. Transfer of these integrated production systems to our customers through fact sheets, management guides, field day presentations, and other mechanisms will lead to increased production efficiency, improved soil quality, rehabilitation of degraded soil resources, improved profitability, and reduced risk.
3. Progress Report:
Progress was made on all three objectives and their subobjectives. Within subobjective 1a, we completed analysis of soil fungal:bacterial (F:B) ratios using quantitative PCR on samples collected over multiple years from research to evaluate the impact of removing residue on soil health characteristics. This research is part of the cross-location ARS Resilient Economic Agricultural Practices (REAP) and national Sungrant projects. Soil samples were analyzed to evaluate the impact of removing residue on soil physical properties. Both of these results were integrated into a manuscript that reports the effects of corn stover removal on soil biological and physical properties at four ARS sites. Manuscripts are being prepared for a special journal issue to highlight research supported by Sungrant on cellulosic ethanol production systems. Row crop and forage crop rotation effects on yield, yield quality and soil condition continued for the 17th year. Samples were evaluated for inorganic carbon which is necessary to evaluate the impact on soil carbon storage deep in the soil profile. Within subobjective 1b: we concluded a seventh year of measuring greenhouse gas (GHG: CO2 + CH4 + N2O) fluxes on a biweekly basis in plots under alternative rotational management. We concluded a fifth year of measuring GHG fluxes on a biweekly basis in plots under differing corn residue removal levels. This project is part of the national ARS project Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet), and data has been entered into the central GRACEnet/REAP database. Research progress within objective 2, hypothesis 2a: Completed yield monitoring in areas of soil removal at the Minnesota site. Data collection is complete for soil properties, weed populations, and crop productivity; results are being analyzed. Soil carbon dynamics study is in progress; changes in soil carbon and other markers are being analyzed. Evaluation of herbicide persistence and mobility was completed. Objective 2, hypothesis 2b: Monitoring is progressing as planned. Progress completed within objective 3 consisted of field experiments to evaluate the impact of crop residue on corn establishment, growth, and yield. Experimental treatments included planting different corn densities (21,000 and 30,000 seed per acre) into multiple crop residues (cool and warm season crops). Additional field studies incorporated the presence of specific cover crops on their impact on the following crop. The following year corn emergence, in season growth and yield was collected. Results were summarized and publications are being prepared.