2006 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? The Mississippi Delta is a major cotton, soybean, and corn producing region. Long growing season, relatively high rainfall, and fertile soils provide an environment conducive for infestation of a wide array of weed species that require intensive control. Sustainable, integrated soil management systems need to be developed by implementing combinations of conservation tillage, cover crops, crop rotation, and herbicide-resistant crops to exploit the benefits of each practice to maximize weed control and minimize inputs. Changes in economics and government policies transformed Delta agriculture from primarily monocrop systems to diverse cropping systems including crop rotations and conservation management. Many best management practices (BMPs) have been prescribed to conserve soil resources and minimize potential non-point contamination of surface water. The effectiveness of combinations of BMPs needs to be assessed. Traditional herbicides have changed formulations and assessments on the environmental fate and potential for sorption and biodegradation need to be assessed. Transgenic crops resistant to the herbicides glufosinate and glyphosate have been commercialized and are accepted by growers for cotton, corn and soybean production. Subsequently, many growers have moved to a cropping system with long-term dependence on only one herbicide. Understanding the effects associated with pesticide use on soil microbial processes are important for maintaining soil sustainability. Thus, risk analysis on the effects of these transgenic herbicide-resistant cropping systems are needed to assess the effects on various plant microbial interactions (symbiotic nitrogen fixation, mycorrhizae) and soil biological processes. This project contributes to Managing Pesticides in Soils (Component. 7)and Understanding and Managing Soil Biology and Rhizosphere Ecology (Component. 1)of the National Program 202 – Soil Resource Management. This project will result in basic understanding of soil biological, chemical and physical factors affecting herbicide fate and the manipulation of these processes by conservation management systems. 2.List by year the currently approved milestones (indicators of research progress) FY 2006 1. Initiate identification of herbicide tolerance vegetative filter strip species 2. Complete first year field studies winter flooding of rice 3. Complete second year of legume cover crops for cotton 4. Complete first year field trials of glyphosate effects on nitrogen fixation and microbial communities FY 2007 1. Identify herbicide tolerance of VFS species 2. Complete lab studies on metolachlor isomer degradation and sorption 3. Complete lab assessments sulfur sources on s-metolachlor degradation 4. Complete second year field studies winter flooding of rice 5. Complete second year of legume cover crops for cotton 6. Complete second year field trials of glyphosate effects on nitrogen fixation and microbial communities 7. Complete greenhouse studies on glyphosate soybean interactions FY 2008 1. Characterize sorption potential of VFS species 2. Complete 3 yr assessment of legume cover crops for cotton 3. Complete field assessments of glyphosate on nitrogen assimilation/fixation in soybean 4. Complete lab and greenhouse studies on glufosinate FY 2009 1 Characterize rhizosphere mediated herbicide degradation of VFS species 2 Complete herbicide persistence in soil in large scale run-off plots 3 Complete field studies on sulfur and s-metolachlor degradation 4 Complete 3rd yr field assessments of winter floodng of rice fields if needed. 5 Complete field studies on effects of glyphosate on microbial communities FY 2010 1 Complete herbicide runoff studies 2 Complete lab studies on s-metolachlor in southern soils 3 Complete field assessments on glufosinate FY 2011 1 Select most effective vegetative filter strip species for reduced leaching of herbicides 2 Complete soil quality studies large scale tillage cover crop plots 4a.List the single most significant research accomplishment during FY 2006. The new project was only approved in late May 2006, Field research proposed has been initiated and too soon in season to ascertain progress. 4b.List other significant research accomplishment(s), if any. None 4c.List significant activities that support special target populations. None 4d.Progress report. None 5.Describe the major accomplishments to date and their predicted or actual impact. None 6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? Poster presentation was made to growers on impact of enhanced atrazine degradation on environmental fat and herbicide efficacy at local field crops day at Mississippi State University Agricultural Experiment Station 7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). None Review Publications Matocha, M.A., Krutz, L.J., Reddy, K.N., Senseman, S.A., Locke, M.A., Steinriede Jr, R.W. and Palmer, E.W. 2006. Foliar washoff potential and simulated surface runoff losses of trifloxysulfuron in cotton. Journal of Agriculture and Food Chemistry 54:5498-5502.