Nitrogen Fertilizers and NH(3)Volatilization: Effect of Temperature and Soil Moisture

The volatilization of ammonia is the main reaction that decreases the efficiency of nitrogen fertilization and in order to reduce losses. new technologies such as addition of N-n-butyltriamide thiophosphate (NBPT) to the conventional urea granule (UNBPT) or the covering with polymer and sulfur (UPS) have been developed with the aim to optimize nitrogen fertilization. This work aimed to evaluate the volatilization of ammonia (NH3) in conventional urea (CU) and fertilizers with associated technology under: (a) three temperature conditions (b) and three soil moisture management. The fertilizer CU presented the highest losses by volatilization of 25.93 mg dm(-3)while fertilizers with associated technology registered 23.93 mg dm(-3)and 8.26 mg dm(-3)for UNBPT and UPS. respectively. The highest volatilization of NH(3)was registered at 45 degrees C for all fertilizers. Fertilizers with associated technology extended the N-release time. delaying the volatilization peak up to the 6(th)day or even promoted the gradual release of fertilizer in the soil. such as UPS. The UNBPT showed the lowest volatilization values in the 1(st)water application. while the CU had lower volatilization values at 25 degrees C (14.48 mg dm(-3)NH(3)) and 35 degrees C (16.99 mg dm(-3)NH(3)) when the matric potential was increased from -100 to -50 kPa in the 1(st)application of water. The UPS did not differ from the volatilization values for the three times of water application.