Tecnologias de inibição da urease como estratégia para aumentar a eficiência da ureia na cultura do milho

Abstract

The use of new technologies for fertilizers has provided a significant increase in the productivity of agricultural crops in Brazil. This gain in productivity is due to the integration of different technologies, such as the development and use of cultivars that are more resistant to field weather, precision agriculture, use of high-performance agricultural machines, as well as the use of chemical and biological inputs. In this consumption, nitrogen fertilizers stand out, providing the element much required by plants, especially for corn, nitrogen (N). And among the main sources of N used in Brazil and in the world, urea stands out. The use of this input is related to its high concentration of nitrogen (45%) and lower cost per unit of N, which provides a reduction in transport costs. To increase the efficient use of N by reducing losses in the form of N-NH3, several techniques can be used. Among them, one of the most promising technologies for increasing N efficiency is the use of stabilized fertilizers containing urease inhibitors, NBPT. NBPT started on the market in 2006 and is being used in Brazil and in many regions around the world. In Brazil and in several countries around the world, the efficacy of NBPT in urea has already been proven to reduce NH3 volatilization. However, to achieve success in the application of these technologies, it is necessary to understand that for it to be efficient, it depends on some factors, which are: temperature, soil moisture and, especially, the local climatic conditions that are decisive for a greater or lesser reduction of N losses. Analyzing this whole issue, it is noteworthy that studies involving the application of NBPT in urea are being improved over the years, and currently, there are other approaches in research involving the storage conditions of the inhibitor to different temperature and when stored in contact with phosphate and potassium fertilizers over time. Therefore, the objective of the first chapter was to analyze the behavior of NBPT coated on urea after storage with conventional and coated phosphate fertilizers, and, furthermore, to determine the half-life of the inhibitor. The second chapter aimed to analyze the different NBPT technologies applied in the corn crop and quantify the stability of these technologies before their use and after application, in coverage, in fertility soil built under a no-tillage system.