2007 Annual Report 1a.Objectives (from AD-416) Research proposed in this project includes both basic and applied research evaluating the impact of agricultural practices (tillage, residue management, soil fertility, and crop rotation) on soil productivity and crop yield and quality. Specific objectives include:. 1)Measure the effects of tillage, residue management, fertility, and crop rotation on physical, chemical, and biological properties of soils in agricultural crop production systems.. 2)Develop crop rotation, nutrient, soil, residue, and pest management practices that improve farming efficiency (increase unit output/unit input), maintain or increase soil productivity, and improve crop yield and quality.. 3)Measure the effects of corn stover/residue removed for biofuel feedstock on: (1) short-term balances of soil C and N; (2) crop yield and quality; and (3) soil resource condition. 1b.Approach (from AD-416) Established long-term field experiments evaluating the effect of crop rotation, residue management, fertility and tillage will be utilized to evaluate the research hypothesis that crop rotations, crop diversity, and crop sequence improves soil quality and productivity and that increased crop diversity, attained through the introduction of alternative crops and improved crop sequences into the traditional corn/soybean rotation, will improve crop yield and quality while maintaining or improving soil quality. To address the hypothesis that no significant effect of genetic modification of corn genotype on soil microbes (DNA compositional measures) and their processes (e.g., C&N transformations) will be detectable, a field experiment will be established evaluating several different corn isolines with and with out genetically modified organisms. Producer cooperators will be identified and research will be conducted on farm to evaluate alternative fertilizer management techniques to improve crop yield and quality. To evaluate the hypothesis that cover crops and integrated weed management strategies will increase biodiversity and enhance sustainable crop production, research will be conducted in two phases. Phase 1 will consist of a small-plot field experiment in which different species of grasses and legumes will be evaluated as cover crops in a corn/soybean/spring wheat rotation. The viability of cover crops as a management tool for weeds and insects relative to chemically-driven pest management will be investigated in Phase 2 of the research. Field and greenhouse experiments will be established evaluating a number of different soybean genotypes to test the hypothesis that soybean genotypes with significantly more root length and mass in the top 10 cm of soil (extensive fibrous root system) will have a more positive impact on soil organic matter, aggregate stability, and soil strength than other soybean genotypes. 3.Progress Report During the 2006 summer growing season a field trial with 35 different soybean varieties was conducted near Brookings, South Dakota. Each plot was one row by six feet long and each variety was replicated four times. About one month after planting three plants per plot were dug and the roots were evaluated for the number of roots in the top three inches of soil. None of the varieties tested had significantly more roots in the top three inches. 4.Accomplishments Organic Matter and Water Stability of Soil Aggregates under Contrasting Crop and Soil Management: Soil conservation or crop management practices that improve soil aggregate stability also help to retard soil loss by maintaining surface conditions resistant to erosion. Objectives of our work were to determine effect of crop rotation and soil management on soil organic matter, components of soil organic matter, and water stable aggregation of soil near the surface, on soil collected from seven sites that represented contrasts between alternative and conventional management. Systems that used less tillage or more diverse rotations (alternative practices) had greater fine particulate organic matter than conventional tillage and monoculture (conventional practices). We conclude that the soil environment under alternative management is either less conducive to microbial transformation of particulate organic matter, and/or highly conducive to new particulate organic matter deposition (for example, through plant root systems that remain undisturbed by tillage). Importantly, we show a relationship between fine particulate organic matter and water stable aggregation that was consistent over a broad spectrum of soil, soil management, and cropping practice; as fine particulate organic matter increased, water stable aggregation increased. This research is part of the Soil Resource Management National Program 202. Specific component #1: Understanding and Managing Soil Biology and Rhizosphere Ecology. This research directly relates to focus area #2: Soil Management to Improve Soil Structure and Hydraulic Properties. Tillage Management and Previous Crop effects on Soil Physical Properties and Corn Yield: While use of no-till soil management and diverse crop sequences improves soil resource conservation, soil health, and interrupts pest cycles, producers in the northern corn belt that use these soil and crop management practices on soils with little internal drainage face two important constraints:. 1)delayed emergence and poor early corn growth, and. 2)unfavorable soil physical properties that may limit crop root growth. Because of the potential positive attributes with the use of diverse crop rotations and no-till soil management on soil resource conservation, research to explore the constraints to widespread adoption of these crop and management practices is warranted. Our research objectives were to characterize soil physical properties, corn yield and seed composition under tilled and no-till soil management, and to investigate the potential role of the previous crop on these parameters. We found that higher bulk density and penetrometer resistance levels under no-till soil management, along with cool soil conditions that typically occur in the spring in the northern corn belt, could work together to reduce corn yield under no-till. Our data also suggest that grain yield reduction was exacerbated in corn grown following winter wheat. We conclude that additional research and development into residue management systems will be needed to develop crop and soil management systems that address this problem. This research was conducted under the auspices of NP Soil Resource Management Nation Program 202 component #5: Adoption and Implementation of Soil and Water Conservation Practices and Systems and focus area #1: Improved Knowledge and Technologies to Expand the Development and Use of New Conservation Systems. Relative Decomposition Rates of Bt+ and Bt- Corn Stover: There is wide-spread anecdotal information within the agricultural community that plant residue from some GM corn hybrids may be resistant to degradation, and implement manufacturers now market improved or alternative tillage machinery to deal specifically with “tough Bt corn residue”. We evaluated residue decomposition rates of Bt and non-Bt corn hybrids over a period of 22 months under field conditions using the litter bag technique. No differences in the decomposition rates of the chopped residue from the four corn hybrids were detected. Additional studies are underway to determine alternate explanations for the perceived toughness of Bt-containing corn residue. If more aggressive tillage is required to handle a growing amount of tougher residue, then decades-long gains in soil and water quality achieved through conservation tillage may be at risk. This research is part of the Soil Resource Management National Program 202. Specific component #1: Understanding and Managing Soil Biology and Rhizosphere Ecology. This research directly relates to focus area #1: Improved Understanding of Soil Biology and Rhizosphere Ecology. Improving Crop Yield and Quality with Variable Rate Technology: As input costs continue to increase, producers throughout the U.S. are seeking ways to maintain crop yield and quality while decreasing production cost. Over the past decade technology was developed and is currently utilized in the southern Great Plains to apply variable rates of nitrogen fertilizer based upon in-season winter wheat plant nitrogen needs. The objective of this research was to expand this technology to different cropping systems throughout the Great Plains. Results from spring wheat and canola trials indicate that existing technology can be utilized to apply variable nitrogen fertilizer in-season based upon plant nutrient status. The average amount of nitrogen needed to obtain maximum yield and quality decreased significantly over traditional soil test nitrogen recommendations potentially decreasing production costs. This research is part of the Soil Resource Management National Program 202. Specific component #4: Nutrient Management for Crop Production and Environmental Protection. This research directly relates to focus area #2: Management Practices and Strategies for Increasing Nutrient Use Efficiency. Question 5 None. 6.Technology Transfer Number of non-peer reviewed presentations and proceedings 26 Number of newspaper articles and other presentations for non-science audiences 37 Review Publications Lundgren, J.G., Lehman, R.M., Chee Sanford, J. 2007. Bacterial communities within the digestive tracts of ground beetles (Coleoptera: Carabidae). Annals of the Entomological Society of America. 100:275-282. Lundgren, J.G., Shaw, J.T., Zaborski, E.R., Eastman, C.E. 2006. The influence of organic transition systems on beneficial ground-dwelling arthropods and biological control of insects and weed seeds. Renewable Agriculture and Food Systems. 21(4):227-237. Osborne, S.L., Riedell, W.E. 2006. Starter Nitrogen Fertilizer Impact on Soybean Yield and Quality in the Northern Great Plains. Agron. J. 98:1569-1574. Osborne, S.L. 2007. Determining Nitrogen Nutrition and Yield of Canola through Existing Remote Sensing Technology. Agricultural Journal. 2:180-184. Osborne, S.L. 2007. Utilization of existing technology to evaluate spring wheat growth and nitrogen nutrition in South Dakota. Communications in Soil Science and Plant Analysis. 38:949-958. Pikul Jr, J.L., Osborne, S.L., Ellsbury, M.M., Riedell, W.E. 2007. Particulate Organic Matter and Water Stable Aggregation of Soil Under Contrasting Management. Soil Science Society of America Journal. 71(3):766-776. 2007(May-June Issue). Riedell, W.E., Osborne, S.L., Pikul Jr, J.L. 2007. Tillage Management and Previous Crop Effects on Soil Physical Properties, Maize Grain Yield, and Seed Composition. Recent Research Developments in Soil Science, 2(2007):1-12.