A simple and accurate Dosi-Tube method for estimating ammonia loss from in-season nitrogen application in corn fields

Ammonia (NH 3 ) volatilization is a major nitrogen (N) loss pathway for surface-applied fertilizers containing urea. The Dosi-Tube method developed by Van Andel et al. on manured fields without a crop canopy measures NH 3 volatilization using wind speed and Dosi-Tubes. Here, we adapted the Dosi-Tube method to accurately and inexpensively measure NH 3 volatilization from fertilizer N applied within corn canopies. NH 3 losses were measured from surface-applied UAN and urea, with or without a urease inhibitor, via both Dosi-Tube and wind tunnel methods over two seasons in Woodslee, Ontario. A newly developed empirical model demonstrated improved accuracy in predicting NH 3 fluxes.