Desenvolvimento de carreadores ambientalmente amigáveis com propriedade de liberação lenta do nitrogênio da ureia fertilizante

Abstract

Nitrogen is an essential macronutrient for growth of plant. Currently, due to the wear and tear over the years and the high demand for food production, the soil cannot provide the necessary nitrogen for plant’s growth. Therefore, the use of nitrogen fertilizer is widely used in agriculture, where urea, due high nitrogen content, is the most used. However, their high losses caused mainly by volatilization of ammonia and nitrate leaching cause the development of systems that reduce the rate of urea. In this study we developed two types of fertilizer urea base and carriers, one in which the urea was mixed with bentonite and another where the urea was mixed with clinoptilolite where for each clay mineral were made three types of fertilizer, by varying the carrier ratios:urea: 1:4, 1:8 and 1:16. Still a third fertilizer was formulated consisting of crushed urea only and mixed with the additives used in formulations such as talc and PVP. All proposals compositions were compressed into cylinders with a diameter of 7 mm and 4 mm in height. The fertilizers were characterized as their morphology, chemistry and mineralogy analysis by XRF techniques, XRD, FTIR, TG / DSC and SEM. The agronomic efficiency was assessed as the loss of 𝑁𝑁𝐻3 by evaporation in humidity and temperature controlled in a greenhouse, using a layer with a depth of 0-20cm a Planosol Haplic and trays as experimental units. Losses were evaluated using static-free semi-open cameras (SALE). They were evaluated dosages equivalent to 100 and 200kg.ha-1, with three replicates for each, and a completely randomized design. The formulated fertilizer showed good capacity storage, where exposed to the atmosphere do not agglomerate. The characterizations show that there were no chemical interactions between the constituents of fertilizers. As for agronomic evaluation showed that formulations used bentonite showed no significant reductions in the losses by volatilization as compared with conventional urea. The formulations used the clinoptilolite as carrier showed considerable reductions in the amount of 𝑁𝑁𝐻3 volatilized, reaching a reduction of 53% to Z1U16.