Tuesday, 7 October 2008

George R. Brown Convention Center, Exhibit Hall E

Robert Schwartz, USDA-ARS, USDA-ARS Consv. & Prod. Res. Lab., PO Drawer 10 2300 Expt. Sta. Rd., Bushland, TX 79012, Thanh Dao, USDA-ARS, USDA-ARS BARC-East Rm. 102, 10300 Baltimore Ave. Bldg 306, Beltsville, MD 20705 and Jourdan M. Bell, Conservation and Production Research Laboratory, USDA-ARS, PO Drawer 10, Bushland, TX 79012

Recent studies indicate that soil extractable P and P in runoff are greatest immediately after fertilizer and manure applications. Our objective was to evaluate changes in Mehlich 3– and water– extractable P in soils amended with cattle (Bos taurus) manure and monoammonium phosphate (MAP) throughout two growing seasons. Cattle manure and MAP were applied at a rate of 184 and 300 kg P ha^-1, respectively, on a Pullman clay loam (Fine, mixed, superactive, thermic Torrertic Paleustoll). Unfertilized checks were included for P extractability comparisons. Grain sorghum (Sorghum bicolor (L.) Moench) was planted after fertilizer applications and received supplemental irrigation. Soil samples (0-150 mm) were collected prior to fertilizer applications and periodically throughout the growing season. Changes in Mehlich 3– and water– extractable P with time exhibited a rapid initial increase after fertilizer applications followed by seasonal fluctuations and a decline 15 weeks after planting.

See more of: Nutrient Availability and Environmental Risk from Land Application (Posters)
See more of: S08 Nutrient Management & Soil & Plant Analysis

2008 Joint Annual Meeting (5-9 Oct. 2008): Phosphorus Dynamics in Amended Soils during a Growing Season: I. Availability and Plant Uptake.

693-6 Phosphorus Dynamics in Amended Soils during a Growing Season: I. Availability and Plant Uptake.