Tuesday, November 3, 2009
Convention Center, Exhibit Hall BC, Second Floor
Approximately 600 million chickens were grown on Delmarva in 2008 producing 680,000 t of chicken manure. Since chicken manure in the form of poultry litter is used to ferti
lize farmland, nutrient runoff from amended soils is a primary concern on the Eastern Shore of Maryland, which abuts the pollution-endangered Chesapeake Bay estuary. We compared conventional methods of litter application (surface application with and without plowing) with the incorporation of litter using a novel technology developed by USDA-ARS to assess losses of phosphorus (P) and selected trace elements (As, Cd, Cu, Fe, Se, and Zn) in runoff from no-till soils. Lysimeters (60 x 60 x 60 cm) were collected from an Othello soil (fine-silty, mixed, active, mesic Typic Endoaquult) after litter was applied at a rate of approximately 6.7 Mg/ha. Lysimeters were subjected to rainfall simulations to compare runoff associated with the alternative litter application methods. Results show that the USDA subsurface band applicator has the potential to lower total P losses in runoff by 63% as compared with broadcasting, although soil conditions affected performance. Trace elements of concern such as As and Zn were lowered substantially in runoff by about two-fold with subsurface band application as compared to surface broadcasting. This study shows promise for improving manure management methods that will provide better surface water quality protection.