Assessment of Soil St ructural Stability Under Different Land Uses Using Some Predictive Indices in Abakaliki, Southeastern Nigeria

Abstract

This study was carried out in order to assess soil structural stability under different land uses using predictive indices. Different land uses of forest land, cattle paddock, fallow land and continuously cultivated farmland were carefully identified within Abakaliki agroecology. Auger and core soil samples were collected at five sampling points using free survey technique in each land use. Core soil samples were used to determine predictive indices of bulk density, total porosity and hydraulic conductivity. Auger soil samples were bulked and used for determination of mean weight diameter (MWD), aggregate stability, dispersion ratio and particle size distribution. Data obtained were subjected to coefficient of variation (CV) analysis and standard deviation. Results showed that sand and clay fractions had little variation (%CV<7-8) but silt fraction varied moderately (%CV >28). Furthermore, bulk density, mean weight diameter, aggregate stability and hydraulic conductivity were highly varied (%CV >112-245), total porosity had moderate variation (%CV >30) and dispersion ratio, high variation (%CV >80), respectively. The different land uses are generally rated according to their performance in their structural stability using the predictive indices as forestland>cattle paddock>fallow land>farmland. It is recommended that the practice of forestry, grazing, fallowing and other management practices which encourage formation and stabilization of soil structural stability be adopted for sustenance of higher soil productivity.