Volatilization of ammonia from urea compacted with sulfur and bentonite in a controlled environment

In recent years, new technologies have been developed to reduce N losses when using urea as a source of this macronutrient. The use of fertilizers with acidic features can reduce ammonia losses from volatilization when combined with urea. The objective of this study was to assess ammonia losses from sources of N with or without coating and/or incorporation of S and bentonite. These fertilizers were applied to the surface of a Haplic Planosol contained in trays (0.1 m2 area and 10 cm deep) at an N rate of 200 kg ha-1. Losses of NH3 through volatilization were evaluated for 21 days with the aid of a semi-open collector. The addition of different sources of S and bentonite in the urea compaction process reduced ammonia loss by up to 29 % when compared with commercial granulated urea, proving to be promising alternatives for increasing the efficiency of N fertilization.

nitrogen loss; compacted fertilizers; NBPT