2007 Annual Report 1a.Objectives (from AD-416) Determine the effect of manure application on soil N and P cycling, manure pathogen fate and transport and organic C storage in soil using two and three year rotations with cover crops and different tillage systems. A. Determine the effect of cover crops on the fate of nutrients applied in swine manure by measuring (a) cover crop N and P uptake and leaching, (b) cover crop survival after manure application, and (c) losses of N2O from manured fields with and without a cover crop. B. Determine the effect of alternative swine manure application methods on nutrient fate and bacterial transport in systems with and without cover crops. 1) Determine effect of application method (surface application with disking versus low disturbance injection) on crop and cover crop uptake of N and P. 2) Determine retention and form of 15N-manure after application to soil. 3) Determine the distribution of bioavailable P in the root zone after manure application. 4) Determine loss of N, P and E. coli in runoff. C. Determine the effects of composted animal manure, tillage and their interaction on C and N cycling in extended corn-soybean rotations containing small grains and/or legumes. 1) Determine the effects of application of composted animal manure on soil and crop C and N within a corn-soybean-winter wheat/red clover rotation under three tillage treatments (fall moldboard plow, fall chisel plow, and no-tillage). 2) Determine the contribution of N from composted animal manure to plant available N within corn-soybean rotations. 1b.Approach (from AD-416) This research examines the use of a rye-oat cover crop to increase manure nutrient retention and to prevent losses of nutrients and fecal bacteria in runoff. The research tests the feasibility of this concept and provides an initial demonstration of this practice to selected growers. If successful the research would form the foundation for field-scale testing and the development of guidelines for producers. Cover crops have been previously shown to be effective in preventing erosion and nitrate leaching, thus they have the potential to mitigate the off-site effects of manure application. Cover crops in the Midwest are established following soybean harvest in October or early November. Swine manure is also applied at this time either as a surface application or by injection. Manure application causes considerable disturbance, thus cover crop survival and function will be assessed. Furthermore, the effects of conventional and low disturbance manure injection equipment will be compared with respect N and P retention and cover crop survival. This research would evaluate the cover crop uptake of nitrogen and phosphorus. The ability of cover crops to mitigate runoff losses of nutrients and fecal bacteria will also be examined in rainfall simulation experiments. In addition, we will determine the effects of composted manure on nitrogen utilization by corn in a rotational cropping system. 3.Progress Report The second year of a field study was completed that examines the effect of rye cover crops on nitrogen (N) cycling and corn growth. N uptake by the cover crop and concentrations of soil nitrate and ammonium were measured following fall application of swine manure. Corn was grown with 15N for the purpose of feeding to swine to produce 15N labeled manure. Lysimeters were established in the field to measure leaching of nitrate derived from 15N labeled manure. Rainfall simulators were prepared for use in fall of 2007 to measure cover crop effects on runoff losses of manure-derived bacteria and phosphorus. 4.Accomplishments Cover Crop Effects on Soil Nitrogen Following Swine Manure Applications. Nitrate leaching in tile drained farm lands is an important issue relative to hypoxia in the Gulf of Mexico. Integration of a rye/oat cover crop with liquid swine manure application may enhance retention of manure nitrogen (N) in corn-soybean cropping systems resulting in reduced potential for nitrate leaching. We conducted a field experiment over two consecutive years to evaluate the effect of a rye/oat cover crop on changes in soil inorganic N following fall injection of liquid swine manure. The rye/oat cover crop reduced nitrate concentrations surface soil (0-7 inches) in the injection band within 21-42 days after manure application. The rye/oat cover crop also reduces nitrate concentrations beneath the manure band to a depth of approximately three feet. Reduced soil nitrate concentrations were obtained by nitrogen uptake by the cover crop. The results indicate that cover crops can be an effective tool for enhancing retention of manure N when used in combination with manure injection. This information will assist in the development of efficient manure nutrient management strategies and provide knowledge for evaluation of these technologies at the field scale. This research contributes to the Systems and Practices for Efficient Nutrient Management, and Control Technologies and Strategies for Emissions Problem Areas in National Program 206, Manure and Byproduct Utilization; and the Nutrient Management Problem Area in National Program 202, Soil Resource Management. 5.Significant Activities that Support Special Target Populations Nothing to report 6.Technology Transfer Number of newspaper articles and other presentations for non-science audiences 1 Review Publications Kelly, J.M., Kovar, J.L., Sokolowsky, R., Moorman, T.B. 2007. Phosphorus Uptake During Four Years by Different Vegetative Cover Types in a Riparian Buffer. Nutrient Cycling in Agroecosystems. 78:239-251.