Ammonia Volatilization from Surface‐Applied Poultry Litter under Conservation Tillage Management Practices

Land application of poultry litter can provide essential plant nutrients for crop production, but ammonia (NH 3 ) volatilization from the litter can be detrimental to the environment. A multiseason study was conducted to quantify NH 3 volatilization rates from surface‐applied poultry litter under no‐till and paraplowed conservation tillage managements. Litter was applied to supply 90 to 140 kg N ha −1 Evaluation of NH 3 volatilization was determined using gas concentrations and the flux‐gradient gas transport technique using the momentum balance transport coefficient. Ammonia fluxes ranged from 3.3 to 24% of the total N applied during the winter and summer, respectively. Ammonia volatilization was rapid immediately after litter application and stopped within 7 to 8 d. Precipitation of 17 mm essentially halted volatilization, probably by transporting litter N into the soil matrix. Application of poultry to conservation‐tilled cropland immediately before rainfall events would reduce N losses to the atmosphere but could also increase NO 3 leaching and runoff to streams and rivers.