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

Poster Number 593

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

Tuesday, 7 October 2008
George R. Brown Convention Center, Exhibit Hall E

Robert Schwartz, USDA-ARS, Bushland, TX, Thanh Dao, USDA-ARS, Beltsville, MD and Jourdan Bell, Conservation and Production Research Laboratory, USDA-ARS, Bushland, TX
Abstract:
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 from this Division: S08 Nutrient Management & Soil & Plant Analysis
See more from this Session: Nutrient Availability and Environmental Risk from Land Application (Posters)