A COMPARISON OF METHODS FOR USE IN THE MEASUREMENT OF AMMONIA EMISSIONS FOLLOWING THE APPLICATION OF LIVESTOCK WASTES TO LAND

During a three week period, comparisons were made between different me thods for measuring ammonia emissions following the spreading of cattl e slurry on grassland. Micrometeorological and wind tunnel methods wer e compared, the former including a range of techniques for determining ammonia concentration in air. Agreement between the basic micrometeor ological and wind tunnel methods was good, with a maximum difference o f 25%. Technical problems with some of the novel techniques (Opsis met hod and Ferm tubes) limited the period during which a complete set of data was obtained. Nevertheless, the preliminary results reported in t his paper indicate good agreement between these methods over a seven h our period and they deserve further investigation.