VOLATIZAÇÃO DE AMÔNIA A PARTIR DE UREOA COMUM E TRATADA COM INIBIDORES DE UREASE

Abstract

The objective of this study was to evaluate the volatilization of ammonia (NH3) from common urea treated with different urease inhibitors, when applied to bare and moist soil. The experiment was carried out in a greenhouse, in a randomized block design, with 5 treatments and 4 replications, in a total of 20 experimental units. Each experimental unit consisted of a plastic tray filled with 9 L of uncovered and moist soil, and the evaluation of NH3 volatilization was carried out using semi-open chambers. An additional control treatment, without urea, was carried out to be used as a blank. The treatments were composed of common urea, urea treated with NBPT (600 mg kg-1 urea) and urea treated with three doses of NBBT+NPPT (600, 450 and 300 mg NBPT kg-1 urea), applied superficially, inside the chambers. , at a dose equivalent to 135 kg N ha-1. NH3 volatilization was evaluated for a period of 28 days. The loss of N–NH3 from common urea applied to bare, moist soil can reach 19.6% of the total N supplied via fertilizer, and 70% of this loss occurs in the first 4 days of application. Compared to common urea, treatments with NBPT (600 mg kg-1 urea) and with three doses of NBBT+NPPT (600, 450 and 300 mg NBPT kg-1 urea) are equally effective in reducing accumulated NH3 losses.