Physicochemical characterization of a Calcisol under different land -use systems in Northeastern Mexico

Abstract

Changes in land use cause variations in the physicochemical characteristics of soil. The present study aims to quantify the changes in the physicochemical characteristics of a Calcisol in three land uses in the Northeast of Mexico: Native Vegetation Area (AVN), Cropland Area (AA) and Pasture Area (ASP). Four composite soil samples were taken at 0-5 and 5-30 cm depth from each land- use plot. The variables bulk density, texture, mechanical resistance to penetration, organic matter, pH and electric conductivity were determined. The analysis of variance showed differences in the organic matter with values of 4.2 % for AVN, 2.08 % for ASP and 1.19 % and for AA in the depth 0-5 cm. The texture was clay loam for AA, silty loam for ASP and loam for AVN showing differences. The soil under the three types of land -use presented low salinity (70.2 to 396.0 μS cm^-1) showing differences at both depths. The soil hardness showed differences (p≤0.05) between plots. The AA showed lower values (0.78 kg cm^-2), contrasting with the values obtained for ASP (2.98 kg cm^-2) and AVN (3.10 kg cm^-2). The pH and bulk density did not show. On the other hand, the decrease of the soil’s organic carbon in the first 5 cm depth was up to 71.6 % when cultivating an area over a period of 60 years that was originally a thornscrub. Furthermore, the abandonment of the cropland for the establishment of a grazing system for 15 years led to a re-accumulation of organic matter up to 21.2 %.