USE OF NITRIFICATION INHIBITORS TO INCREASE FERTILIZER NITROGEN RECOVERY AND LINT YIELD IN IRRIGATED COTTON

Abstract

This paper describes field experiments designed to evaluate the effectiveness of several nitrification inhibitors to prevent loss of fertilizer nitrogen (N) applied to cotton. The usefulness of nitrapyrin, acetylene (provided by wax-coated calcium carbide), phenylacetylene and 2-ethynylpyridine to prevent denitrification was evaluated by determining the recovery of N applied as15N labelled urea to a heavy clay soil in 1 m × 0.5 m microplots in north western N.S.W., Australia. In a second experiment, the effect of wax-coated calcium carbide on lint yield of cotton supplied with five N levels was determined on 12.5 m × 8 m plots at the same site. The15N balance study showed that in the absence..