Estimating Ammonia Loss from Sprinkler‐Applied Swine Effluent

Abstract

Volatilization of NH3 from sprinkler‐applied effluent is a major N loss pathway in the Great Plains region, but there is disagreement as to how much of the total NH4–N applied in effluent is lost. The objectives of the study were to determine NH3 loss during sprinkler application and from soil and to determine the amount of mineral N available to the crop over a series of swine effluent application rates, effluent sources, and field conditions. A 3‐yr study was conducted on fields near swine (Sus scrofa) production operations. A mass balance method was used to estimate N loss during and after effluent application at rates of 1.3, 1.9, and 2.5 cm. Change in inorganic N concentration in effluent captured below the sprinkler was used to estimate volatilization during application, and the change in inorganic N concentration in soil (before and 72 h after application) was used to estimate N loss from soil. Ammonia loss during application ranged from 8 to 27% of the total NH4–N in the effluent due to drift and volatilization. The range of estimated N loss from the soil varied from 24 to 56% of the NH4–N in the applied effluent. The total N loss from both the sprinkler application and the soil ranged from 32 to 83%, with an average loss of approximately 58%. Effluent N concentration did not significantly impact the percent of N lost, while air temperature and wind speed were significant variables in the percent of N lost.