Effect of application method, manure characteristics, weather and field conditions on ammonia volatilization from manure applied to arable land

To predict ammonia (NH3) volatilization from field-applied manure, factors affecting volatilization following manure application need to be known. A database of field measurements in the Netherlands was analysed to identify these factors and to quantify their effects on the volatilization of NH3 from liquid pig manure applied and incorporated on arable land. The combination and the statistical analysis of these data, together with the models that were designed, yielded valuable information about the factors that influence NH3 volatilization, and about the magnitude of their effects when applying and incorporating manure on arable land. Factors analysed were application method, characteristics of the manure, weather and field conditions. The mean total volatilization, expressed as % of the total ammoniacal nitrogen (TAN) applied, was 68% for surface spreading, 17% for surface incorporation and 2% for deep placement. The volatilization rate increased with an increase in TAN content of the manure, manure application rate and air temperature. Wind speed had a substantial effect on the volatilization rate, only when manure was surface applied or surface incorporated. The results show that useful prediction of ammonia volatilization following manure application on arable land in the Netherlands is feasible on the basis of information about application method, characteristics of the manure and weather conditions. (C) 2003 Elsevier Ltd. All rights reserved.