Monday, November 5, 2007
99-6

Mineralization of Broiler Litter as Affected by Soil Texture in the Southeastern Coastal Plain.

Robert K. Hubbard1, David Bosch1, Laura Marshall2, Timothy C. Strickland2, Diane Rowland3, Timothy Griffin4, C. Wayne Honeycutt4, Stephan Albrecht5, Karamat Sistani6, H. Allen Torbert7, Brian Wienhold6, Bryan Woodbury6, and J. Mark Powell8. (1) Southeast Watershed Research Laboratory, USDA-ARS, 2390 Rainwater Rd. P.O. Box 748, Tifton, GA 31793, (2) Southeast Watershed Research Laboratory USDA-ARS, P.O. Box 748, Tifton, GA 31793, (3) USDA-ARS Nat'l Peanut Research Lab, PO Box 509 1011 Forrester Dr. SE, Dawson, GA 39842-0509, (4) USDA-ARS-NEPSWL, University of Maine, Orono, ME 04469-5753, (5) Columbia Plateau Conservation Research Center, PO Box 370, Pendleton, OR 97801-0370, (6) USDA-ARS, 230 Bennett Lane, Bowling Green, KY 42104, (7) USDA-ARS National Soil Dynamics Lab., 11 South Donahue Drive, Auburn, AZ 36832, (8) USDA-ARS Dairy For. Research Ctr., University of Wisconsin-Madison, Madison, WI 53706

A field study was conducted during 2004-2005 to determine nitrogen (N) mineralization of broiler litter (BL) in two Coastal Plain soils of differing texture, sandy or clayey. The soils were Tifton loamy sand (fine-loamy, siliceous, thermic, Plinthic Kandiudults) and Greenville sandy clay loam (clayey, kaolinitic, thermic Rhodic Kandiults). These soils represent the broad range in surface textures commonly found in soils used for agricultural production in the southeastern Coastal Plain. Published protocols used for the study were designed by the ARS mineralization team. Amounts of N in the soil from BL mineralization were similar for both soils, 46 ug/g and 41ug/g for the Tifton and Greenville soils respectively, but differences occurred in mineralization timing. Mineralization of the BL was complete on the sandy soil in 28 days, while mineralization on the clayey soil was not complete until 70 days or later. Previous research has shown that mineralization rate is positively correlated with sand content and negatively correlated with clay content of soils, and the results of this study concurred with those findings. From these findings it can be concluded that land managers, when possible, should apply BL later on the sandier soils than on the clayey ones to maximize use of mineralized N by crops and minimize potential losses of this N by surface runoff or leaching.