Determination of Soil Moisture for Sandy Soils Using Gas and Microwave Ovens

Since there are several methods used to determine soil moisture, the objective was to compare the moisture values obtained with the use of a gas oven and a microwave to the values obtained with the standard oven method. Having been carried out at the Hydraulics Laboratory of the State University of Maringá, Umuarama Regional Campus, the performance of the methods was evaluated in the determination of five levels of moisture (10, 15, 20, 25, and 30%), with dry masses obtained at 15, 20, 25 and 30 minutes for the gas oven and at 2, 4, 6 and 8 minutes for the microwave. The best drying times were selected using the Taylor Diagram. Linear regression was performed between the methods, in order to obtain the correlation coefficient (r), the Willmott agreement index (d), the performance index (c), absolute error (EA), absolute mean error (ERA), and root mean square error (RQME). By analyzing the results obtained, it can be stated that the gas oven method and the microwave method presented excellent performance when compared to the standard method. It was also concluded that the time of 25 minutes for the gas oven method was efficient and, for the microwave method, the drying time of 8 minutes was sufficient, meaning a reduction in the time for moisture determination.