Abstract:
Land use changes have remarkable effects on the dynamics of soil properties. This study was conducted in 2019 at Necho Watershed; Northwest Ethiopia with the objective of analysis of land use dynamics and its effect on selected soil physico-chemical properties. The land use dynamics were determined by analyzing Landsat satellite images of 1988, 2003, and 2019 using ERDAS 2014 and Arc GIS 10.3 software download from USGS website center. Four major land use types; natural forest, grazing land, cultivated land and plantation forest were selected while the soil sample were collected with 0-20cm and 20-40cm soil depth. Disturbed composite and undisturbed core soil samples were collected. The soil samples were analyzed following the standard soil analytical procedures in the Bahir Dar soil testing laboratory. The result that forest/plantation land covers were increased while cultivated and grazing lands decreased. The statistical analysis of soil properties revealed that, all the selected soil parameters were significantly (p<0.05 and/or p < 0.01) affected by land use types. The clay, bulk density, soil organic matter and total nitrogen, available phosphorus, exchangeable magnesium, sodium, and cation exchange capacity were significantly affected (p < 0.05 and/or p < 0.01) by soil depth. But, the sand and silt contents, soil pH, exchangeable calcium and potassium were not significantly (p >0.05) affected by soil depths. The lowest mean bulk density, the highest fraction of clay, soil pH, soil organic matter, total nitrogen, available phosphorus, cation exchange capacity and exchangeable base were recorded in forest land. In soil depth sand, silt, soil organic matter, total nitrogen, available phosphorus and cation exchange capacity decrease with increase soil depth, Whereas clay, bulk density, soil pH and exchangeable bases were increased with increasing soil depth. This variation might be due to inappropriate land use management led to disturbance of soil nutrient status, indicating that the soil condition in the cultivated land and plantation forest is getting below the condition of soils under natural forest and grazing lands. Therefore, immediate intervention is needed to protect the remnant natural forest and to replenish the degraded soil properties proper land use plan and soil water conservation are important to enhance and sustainable soil fertility and agricultural productivity.
Keywords: Land use type, Soil depth, deforestation, Land management, Soil properties