Monitoring magnetic susceptibility and spatial distribution of soil attributes in different land uses: a case study in an arid and semi-arid region, southern Iran

Abstract

The magnetic susceptibility (MS) technique could be used as an efficient tool for management, monitoring, and analysis of soil properties. This study was conducted to investigate the relationship among the magnetic parameters and soil surface properties as well as their spatial variation in different land uses in Fars Province, southern Iran. Three dominant land uses in the study area including cropland, barren, and pasture were selected, and a total of 72 samples were collected from the soil surface (0–15 cm). Physicochemical properties, total free (Fed) and amorphous (Feo) iron forms, and MS in both high (xhf) and low (xlf) frequencies were determined. The results showed a significant difference (p˂0.05) for xlf average values among different land uses which were decreased in the order of cropland (45.31× 10−8 m3 kg−1), barren (31.68 × 10−8 m3 kg−1), and pasture (17.84 × 10−8 m3 kg−1), respectively. There was a positive significant correlation (p <0.01) between the MS values and Fed and Fed-Feo, while a negative significant correlation was observed among xlf and EC, gypsum, and Feo/Fed. The spherical model suitably described the spatial behavior of magnetic parameters and soil properties. The spatial distribution maps represented an almost parallel pattern in the spatial variations of MS, Fed, Fed-Feo, and evolution index, but an inconsistent pattern for Feo, CaCO3, gypsum, and EC in the study area. This indicates the role of diamagnetic materials in decreasing the soil magnetic properties. Results of this study clearly revealed that the MS technique is of great potential in monitoring the spatial variations of soil properties.