Quantifying Ammonia Volatilization from Swine Effluent Applied Calcareous Clay Loams in the Southern Great Plains

A study conducted during summer of 2004 and 2005 to evaluate ammonia volatilization from swine effluent on calcareous clayey loam soils. Ammonia volatilization from applied swine effluent ranged from 21.7% to 57.8 %. On an average, 58% of the total volatilization loss occurred within 12 hrs of application. The plant material significantly reduced volatilization loss as compared to conventional till soils. The second objective to evaluate measured ammonia volatilization from swine effluent applied conventional till, no-till and buffalograss production system compared to a mechanistic model. The predicted volatilization was 25% and 70% greater in magnitude compared to measured values under buffalograss and no-till systems, respectively. The present model predicted patterns of NH3 volatilization from swine effluent when applied to fallow systems. For model predictions in no-till systems, saturated hydraulic conductivity of the soil based on the percent residue cover on the ground has to be measured.Department of Plant and Soil Science