Influência da textura e mineralogia na determinação da umidade de solos utilizando micro-ondas

Abstract

The moisture obtained by the greenhouse method presents the time required to obtain it as an inconvenience. As an alternative, it has been suggested to obtain moisture a microwave. However, clay soils with high levels of oxides have shown a peculiar behavior when subjected to electromagnetic radiation. Thus, aiming to speed up the process of quantification of moisture in soils, the possibility of using the microwave oven to determine the humidity of Oxisols with contrasting textures and varied levels of iron and aluminum oxides was evaluated. Deformed samples from the Bw horizon of ten Oxisols were used. In triplicate, tests were carried out to obtain moisture using the oven methods (105ºC / 24 hours) and microwaves. The microwave tests were carried out with the Turntable Microwave Oven device, with a calibrated power of 800 W.J.s-1 . The data obtained were submitted to the Tukey means comparison test (5%). Only 6 minutes of drying in the microwave were sufficient to obtain results similar to the greenhouse methods. Clayey Oxisols with higher levels of iron and aluminum oxides remained more moisture. Microwave oven is the most feasible method and gives reliable results for determining soil moisture content with the shortest time.