Tuesday, November 6, 2007
222-7
Nnutrient Dynamics in a Soil, Plant and Runoff System as Influenced by Broiler Litter Management.
Ardeshir Adeli1, John P. Brooks2, Dana Miles2, Dennis Rowe3, and John J. Read2. (1) USDA-ARS Invasive Weed Management Research Unit, USDA-ARS Waste Mngmnt & Forage, 810 Hwy 12 East, Mississippi State, MS 39762, (2) USDA-ARS, Waste Management & Forage Research Unit, 810 Hwy 12 East, Mississippi State, MS 39762, (3) Experimental Statistics, Mississippi State University, Mississippi State, MS 39762-5367
Poultry litter contains multiple nutrients, including N, P, K, Ca, Mg, and micronutrients and can be considered as an excellent organic fertilizer if properly managed. Offsite movement of nutrients from land applied poultry litter into the water bodies is of national concern. Studies have shown that with proper management practices, broiler litter can be a valuable source of nutrients for crop production with minimal adverse impact on soil and water qualities. This study was conducted on a Mariate silt loam (fine-loamy, siliceous, active, thermic Fluvaquentic Eutrudepts) soil to determine the effects of N-based and P-based broiler litter applications to the forages on dry matter, soil nutrient accumulation and runoff losses of nutrients. Experimental design was a randomized complete block with three replications. Treatments included control, N-based, P-based with supplemental N, and commercial fertilizer N and P at recommended rate. Individual plot dimension was 14 ft by 7 ft. No significant difference in N removal obtained between N-based and P-based broiler applications. However, P and N use efficiency was greater for P-based than N-based resulted in lowering runoff nitrate N and P by 68% and 65%, respectively in P-based as compared to N-based broiler litter. The concentration of Cu and Zn in runoff reduced by 30% and 42% in P-based than N-based broiler litter application. Ammonia fluxes from volatilization process was significantly lower in P-based and occurred within the first 3 hr after litter application. Residual soil NO<sub>3</sub>, P, Cu and Zn concentrations were much greater in N-based than P-based treatments, indicating application of broiler litter based on crop P requirements agronomically and environmentally sound.