Wednesday, November 7, 2007 - 4:15 PM
319-4

Nutrient removal by a Rye Cover Crop after Poultry Litter Application to Sorghum-Sudangrass.

Rebecca Gilfillen1, Byron Sleugh2, W.T. Willian1, and Matthew Futrell1. (1) Agriculture, Western Kentucky Univ., 1906 College Heights Blvd #41066, Bowling Green, KY 42101-1066, (2) Dow AgroSciences, 6887 Dakota Dr., West Des Moines, IA 50266

Excess nutrient accumulation has been a consistent problem with application of poultry litter at higher rates. This study was established in 2005 to look at the added benefit of adding a Rye cover crop to a field growing Sorghum-Sudangrass. There were a total of 4 treatments with 4 replications. These four treatments consisted of: N rate of litter application (NL), P rate of litter application (PL), P rate of litter application plus inorganic N (NPL), and inorganic fertilizer (INORG). Half of the study had a cover crop while the other half remained fallow over the winter months. Nutrient removal was measured in soils with and without a cover crop. Soils were analyzed for pH, P, K, Cu, and Zn. In this two year study, no differences were seen in soil nutrient accumulation based on having a Rye cover crop compared to leaving the ground fallow (p<=0.05). Differences were seen in P, K, Cu, and Zn based on fertility treatments (p<=0.01). In general, the lack of nutrient removal by the Rye cover crop may be linked to the short growth time or the abbreviated observation of this study to date.