Determinação da umidade do solo por radiações de micro-ondas.

Abstract

The primary objective of the present work was to test the applicability of a commercial microwave oven for moisture determination by drying samples. of soil. For this, two treatments were chosen: a) establishment of a standard methodology, verifying the wetness of the obtained and studying the effects of the heating in the organic matter of the soils, besides a determination of the drying time for a given humidity; b) to test the applicability, determining the humidity by microwave during a pre-established time, and comparing the results with those obtained in the conventional oven and infrared radiation. The tests were developed at the Water and Soil Laboratory of the National Department of Drought Works (DNOCS) and the Wallig Northeast Industry Chemistry Laboratory. The results showed that the humidity obtained from microwave drying were not very different from those obtained by the gravimetric method. 0 time to Dry samples of air-dried soil for 20 - 45 minutes, depending on moisture and weight. The effect of microwave heating on soil organic matter has been as much as that of the conventional greenhouse at 105 ° C for 24 hours. The parameters of the linear equations, calculated to estimate the drying time for different humidity, did not depend on the soil texture. The general equations for different soils showed no significant differences with those obtained for each soil separately. The suggested method was compared with gravimetric and infrared radiation methods using 15 soil samples of different textures. Similar results were obtained for the three methods using saturated soils. and air-dried soils. So there is a possibility of using a commercial microwave oven to determine soil moisture in the laboratory.