Comparison of low-cost methods for measuring ammonia volatilization

Authors: SHIGAKI, FRANCIROSE - Federal University - Brazil; Dell, Curtis

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2015
Publication Date: 7/1/2015
Citation: Shigaki, F., Dell, C.J. 2015. Comparison of low-cost methods for measuring ammonia volatilization. Agronomy Journal. 4107:1392-1400.

Interpretive Summary: Measuring nitrogen losses, as ammonia, from applied fertilizers is critical to the development of management practices that maximize economic return and minimize environmental impacts. However, alternative, low cost ammonia measurement methods are needed, especially in developing nations. Three low-cost methods were tested and compared with ammonia recovery rates obtained with a more costly chamber system. A semi-open chamber, using an acidified sponge for ammonia collection, provided the greatest ammonia recovery, was the least expensive, and easiest to use.

Technical Abstract: Nitrogen fertilizer application to improve crop production is increasing worldwide, and subsequent nitrogen losses via ammonia emissions generate undesirable economic and environmental consequences. Thus, low cost and practical methods to quantify ammonia emissions are essential for the development of management practices that minimize environmental impacts. The objective of this study was to compare different methods to quantify ammonia loss following N fertilizer application (urea) to a grass field and indoor soil boxes. The methods tested were: semi-open chamber (SOC), open-collector (OC), closed chamber (CC) and a recirculating chamber (RC). SOC and OC were shown to be equally efficient. Cumulative recoveries through 216 h for the outdoor study were 9.5 and 8.5 kg ammonia-N per ha for OC and SOC (respectively), corresponding to 8 and 7 percent of the applied N. The closed-chamber recovered only 3.6 percent of applied N. For the indoor study, higher recovery rates were observed with all methods. Cumulative losses measured through 216 h did not differ between SOC and OC (24.4 and 24.9 kg ammonia-N per hectare, respectively) and represented about 20 percent of N applied. However RC and CC recovered only 10 to 12 percent of the applied N (14.8 and 12 kg ammonia-N per ha, respectively), which was significantly less than amounts recovered with OC and SOC. Results from this study show that semi-open and open collectors are simple, practical, and low cost tools for quantifying ammonia emissions either for indoor and outdoor studies compared with closed and recirculating chambers which presented disadvantages such as low ammonia recovery and higher costs.