Evaluation of the use of spectroradiometry for the determination of soil exchangeable ions after the application of mining coproducts

Abstract

This study aimed to evaluate the use of spectroradiometry for the determination of soil exchangeable ions after the application of mining coproducts. The treatments were arranged in a double factorial scheme (7 × 2) with complete randomization and ten repetitions, and placed in pots in a greenhouse. The factors evaluated were the input type and soil class (Arenosol and Ferralsol). The inputs were limestone mining coproducts, which were applied in isolation and in blend. After 140 days, exchangeable ions and soil spectra were determined. The application of the coproducts increased the exchangeable ion contents: K+, Mg2+, Ca2+, P, SO42− and Si. Moreover, estimation of the attributes through spectroradiometry showed satisfactory results for the Ca2+, K+ (resin and mehlich-1), P and Si from the soil, with R2 in the prediction phase equal to 0.89, 0.96, 0.87, 0.71 and 0.92. For Mg2+ and SO42−, R2 values were 0.44 and 0.12. Therefore, we conclude, under the conditions described in this paper, that spectroradiometry has the potential to determine some exchangeable ions, similar to routine soil fertility analyses.