Using magnetic susceptibility mapping for assessing soil degradation due to water erosion

Abstract

Jaksik O., Kodesova R., Kapicka A., Klement A., Fer M., Nikodem A. (2016): Using magnetic susceptibility mapping for assessing soil degradation due to water erosion. Soil & Water Res., 11: 105–113. This study focused on developing a method for estimating topsoil organic carbon content from measured massspecific magnetic susceptibility in Chernozems heavily affected by water erosion. The study was performed on a 100 ha area, whereby 202 soil samples were taken. A set of soil samples was divided into 3 subsets: A (32 samples), B (67 samples), and C (103 samples). The mass-specific magnetic susceptibility using low ( χ lf ) and high ( χ hf ) frequency, and organic carbon content were measured at all soil samples. The contents of iron and manganese, extracted with a dithionite-citrate solution (Fe d , Mn d ) and ammonium oxalate (Fe o , Mn o ), were quantified in A and B samples. Models for predicting organic carbon content from magnetic susceptibilities were designed as follows: (1) subset A was used as the training set for calibration, and subsets B and C were used as the test sets for model validation, either separately (subset B only), or together (merged subsets B and C); (2) merged subsets A and B were used as the training set and subset C was used as the test set. Results showed very close correlations between organic carbon content and all measured soil properties. Obtained models relating organic carbon content to mass-specific magnetic susceptibility successfully predicted soil organic carbon contents.