Effects of thickness of solid media, ventilation rate, and chamber volume on ammonia emission from liquid fertilizers using dynamic chamber‐capture system (DCS)

This study was conducted with the aim of improving the dynamic camber‐capture system, which estimates ammonia emissions during the application of liquid fertilizer from livestock manure. We focused on the volume of the chamber and headspace, the height of the solid media, the flow rate of the pump, and the ventilation rate. Total ammoniacal nitrogen (NH₃ + NH₄⁺) is an important factor affecting ammonia volatilization. Even though the characteristics of liquid fertilizer were changed, the effect of total ammoniacal nitrogen on ammonia volatilization remained the largest. Increasing the thickness of solid media inside the chamber has the effect of reducing ammonia emission by reducing the contact area between liquid fertilizer and air. Although it is very difficult to measure and control the wind velocity in a chamber using a general vacuum pump, it can be indirectly evaluated through the ventilation rate in the macroscopic aspect. The higher the ventilation rate, the faster the flow of air in the chamber, which is linear with the increase in ammonia emission flux. We find that it may be necessary to improve the steady wind velocity within the chamber and of the linkages to upscale the wind tunnel system.