Spatial variability of ambient ammonia in the vicinity ofa broiler farm

摘要

Ammonia (NH_3) emissions from agricultural sources affect the air quality in negative manner. The objective of this study was to quantify NH_3 emissions from a commercial broiler farm by measuring weekly averages of atmospheric NH_3 at different locations at the same time during two growing cycles. Thus, it was possible to analyze the spatial occurrence of NH_3 in air and assess the environmental impact of the farm. For detecting NH_3 in air, passive sampling was used at five locations in the immediate vicinity of the farm. The inside NH_3 concentrations and the performance of the air volumetric flow rate were measured continuously during the growing cycles inside one broiler barn. In addition, the wind direction was detected.The NH_3 emissions out of the broiler barns increased over time of the observed growing cycle due to the rising excretion rates of the growing broilers. The observed emissions varied between 2.7 and 3.8 g NH_3 per broiler and growing cycle. The farm as aNH_3 source caused an increase of atmospheric NH_3 in the immediate vicinity, detected by the passive samplers used. The amounts of NH_3 varied in space and time and were strongly influenced by the prevailing wind direction. These issues are important to consider assessing environmental influence ofNH_3 sources.