Thermal Performance and Degradation of Urea as a Result of Time and Storage Location

This research aims to analyze the degradation of urea in its storage process, observing the environmental conditions of the storage building and also the storage time. In order to carry out such analysis, a field experiment with a completely randomized design (CRD), 3 × 4, was set up, with eight 50 kg bags divided in four different locations, being a shed, an underground basement, and two reduced models built in wood, where one received thermal input minimization treatments and the other with simplified coverage and closings. Within the four environments, temperature (DBT) and temperature (WBT) were measured, where it was possible to obtain the relative humidity values enabling thus crossing the internal climatic data with the process of urea degradation in storage for a period of three months. To analyze urea degradation, the analytical manual of fertilizers of the Ministry of Agriculture (MAPA) was used. The analyses of the physicochemical parameters of nitrogen content, density, humidity, total bag weight, and also granulometry were carried out monthly. The data were validated by one (ANOVA) and Tukey test with 5% probability of error. The results show that the environments with higher temperatures had a higher volatilization of nitrogen, the losses reached about 13% during the evaluated period. Losses of up to 5.3% of the density of the analyzed samples were also observed. In relation to the initial weight of the bags, losses totaled a reduction of 1.5%. It was also possible to conclude that the lowest losses were recorded in places where there was greater ventilation during the day, where the thermal inertia of the building dissipated.