Abstract
An experiment, using the micrometeorological mass balance method, was conducted to determine the effect of pasture sward height on volatilized nitrogen (N) losses. An altered sward structure (cut to a height of 30 mm) demonstrated higher volatilized N losses after fertilizer application than a sward retaining approximately 1.00 mm of residual herbage. The mean difference between treatments was estimated at 765 ± 109 g N ha‐1 (P<0.05) for 33 h after the application of urea at 50 kg N ha‐1. This implies that residual herbage remaining on a pasture at the time of N fertilizer application may reduce volatilized N from the pasture.