Land use dynamics and its effect on selected soil physicochemical properties in Necho watershed, northwest Ethiopia

Abstract

This study was conducted in the Necho watershed, northwest Ethiopia with the objective of determining the impact of land use dynamics on selected soil physicochemical properties. The land use dynamics were determined by analyzing Landsat satellite images from 1988, 2003, and 2019 using ERDAS 2014 and Arc GIS 10.3 software (where ERDAS and GIS are earth resource data analysis system and geographic information system, respectively). Four major land use types, natural forest, grazing land, cultivated land, and plantation forest, were selected and soil samples from 0- to 20-cm and 20- to 40-cm soil depth were collected from disturbed and undisturbed sites. The land use change analysis shows an increase in forestland, whereas cultivated and grazing lands have decreased. The analysis of soil properties revealed that clay, bulk density (BD), soil organic matter (SOM), total nitrogen (TN), available phosphorus (AP), exchangeable magnesium, sodium, and cation exchange capacity (CEC) were affected (p < 0.05) by soil depth and land use types. The lowest densities and the highest fraction of clay, soil pH, SOM, TN, AP, CEC, and exchangeable base were recorded in forestland. All soil parameters decrease with increasing soil depth except clay, BD, soil pH, and exchangeable bases. The soil parameters in cultivated land and plantation forest were lower than natural forest and grazing lands. Therefore, immediate intervention to protect the remnant natural forest and to replenish the degraded soil properties is needed.