Development of a simple and affordable method of measuring ammonia volatilization from land applied manures

Quantifying ammonia (NH3) flux following fertilizer and manure nitrogen (N) application is crucial to develop sound management practices. Traditional methods used for obtaining these measures are expensive, inefficient, or inaccurate. The objective of this study is to develop a method using a passive dosimeter and a semi-open static chamber to provide an economical and simple solution to measure NH3 loss following nitrogen application. Dosimeter tubes were commercially developed to measure ammonia exposure, providing a time-weighted average. In this study, chicken manure was applied to short grass and the ppm h reading obtained using the dositube ammonia method was calibrated against a reference measure of NH3 loss (kg N ha-1) using a wind tunnel and acid trap method. A calibration was developed (Estimated Total Loss (kg N ha-1) = (0.217Dw) - (0.034D) + 0.71), which requires the dositube (D, ppm h) to be read every 24 h and placed at a height of 0.15 m in the dositube chamber, with wind speed (w, m s-1) measured at a height of 0.3 m and averaged over the coinciding time period. This calibration may also be applied where dositubes are read every 48 h; however, 24 h periods are recommended to achieve the greatest accuracy.