Additives incorporated into urea to reduce nitrogen losses after application to the soil

Abstract

The objective of this work was to develop urea-based fertilizers with internal incorporation of urease inhibitors and other additives in the granule. The effects of the incorporation of NBPT, copper (Cu+2), boric acid (H3BO3), elemental sulphur (Sº), and a clay mineral from the zeolite group in powder urea - with ten different combinations of these additives - were evaluated as to N losses by volatilization and leaching. The losses in laboratory-developed formulations were compared with those of commercial fertilizers coated with the same additives (Super N, FH Nitro Mais, and FH Nitro Gold). The evaluations were made in greenhouse conditions, using a Ultisol accommodated in PVC columns. Nitrate and ammonium leaching was evaluated in the solution percolated through the soil columns. Ammonia volatilization was measured with a semi-open static chamber. The incorporation of urease inhibitors (NBPT, H3BO3, and Cu+2) into the urea granules was efficient to reduce N volatilization. Ammonia volatilization in the laboratory-developed ureas was lower than in commercial fertilizers coated with the same additives, while ammonium sulfate losses by leaching were similar. The addition of zeolite does not reduce N volatilization. Mineral N leaching in the soil profile is not affected by urease inhibitors.

Nitrogen fertilization in super-early cycle common bean using new sources of urea

“…This result is probably associated to the effect of zeolite on the reduction of ammonia volatilization losses, which contributed to a higher efficiency of nitrogen fertilization and increased N uptake by plants as observed by Werneck et al (2012). In contrast, Rech et al (2017) found no decrease in loss by volatilization with zeolite addition.…”

“…The urea sources associated both with zeolites and with urease inhibitor have proven efficiency in the literature regarding the reduction of nitrogen losses by volatilization when compared to the use of traditional urea (Pereira et al, 2009;Scivittaro et al, 2010;Werneck et al, 2012;Rech et al, 2017). In this way, the plant can absorb more nutrients, contributing to greater grain weight in these treatments.…”

“…Urea is considered the main nitrogen source used in agriculture due to its lower cost (Rech et al, 2017). However, when applied to the surface, the loss of nitrogen by ammonia (NH 3+ ) volatilization to the atmosphere is considered high, whose magnitude will depend on edaphoclimatic characteristics, reaching values close to 60% loss of applied nitrogen (Rochette et al, 2013).…”

“…These products can considerably reduce the loss of NH 3+ , allowing more time for the fertilizer to be incorporated into the soil by rain or irrigation, without the occurrence of losses. The urea inhibitor NBPT (N-(n-butyl) thiophosphoric triamide) has been tested in several countries, showing efficiency in the reduction of nitrogen losses by volatilization when compared to traditional urea use (Pereira et al, 2009;Scivittaro et al, 2010;Rech et al, 2017). NBPT prevents the urea molecule from being broken down, inactivating the enzyme urease, thus avoiding losses by volatilization (Cantarella et al, 2003).…”

The Role of Nanotechnology in the Fortification of Plant Nutrients and Improvement of Crop Production

“…There could be addition of nitrification inhibitors, stabilizers or additives when the nitrogen fertilizers are applied to reduce the loss of NH 3 formed during the course of reaction of the fertilizers with the soil and water molecules. Such compounds may include NBPT [N-(n-butyl) thiophosphoric triamide], boric acid, which can be used with urea or urea-ammonium nitrate fertilizers and they function to slow the action of urease bacteria that transforms the fertilizers to NH 3 [54]. Such action allows the fertilizers to be well absorbed by the soil, giving room for reaction with enough water molecules.…”