1a.Objectives (from AD-416)
The overall objective is to develop soybean cropping systems that reduce disease and nematode incidence, maximizing yield and economic return.
1b.Approach (from AD-416)
The Tennessee Agricultural Experiment Station (TAES) will use existing and new research plot areas to measure the effects of soybean cropping systems variables, such as no-tillage, cultivar selection, seeding rate, planting date and use of animal waste, on diseases and soybean yield. This will be done on cropping systems experiments already in place at University of Tennessee (UT) and on experiments being conducted by USDA, ARS scientists in the Crop Genetics and Production Research Unit. TAES will provide expertise in possible cropping system changes to enhance economically and enviromentally viable soybean production.
An experiment comparing poultry litter application rates in tilled and no-tilled soybeans was completed in the last year. Three year results indicate no effect of manure application on reducing the reproduction of the soybean cyst nematode. Soybean yields in the third year were increased by litter application. Statistical analysis is showing spatial yield and nematode population differences across the experiment and geostatistics are now being used to further analyze results. The influence of microflora populations as influenced by a long term tillage treatments on the soybean cyst nematode and charcoal rot infestation is still underway. Results indicate that both tilled and no-tilled plots are dominated by bacteria over fungi, but changes in microflora have not been strongly related to shifts in nematode levels or reproduction. The data are still indicating that a shift from no-tillage to tillage can enhance nematode reproduction; however, after six years post tillage, the differences in reproductive rate are less dramatic. Significantly lower levels were seen in all soybean rhizosphere organisms during 2007 when a severe drought occurred. Analysis of charcoal rot infestation data as influenced by treatments is underway. Normalized vegetation index is being used in both experiments to help quantify above ground biomass as influenced by disease incidence. ADODR used site visit, email and telephone conferences to monitor activities of the project.