An Assessment of Soil Degradation in Zaria Area, Kaduna State, Nigeria
This study assessed soil degradation in the Zaria area and entailed field assessments of the physico–chemical status of surface soils of the area with a view to demonstrating its degradation. Twenty five composite soil samples were taken at 0-15 cm depth from plantation, badland, fadama, cultivated and scrubland landuses and analysed for key soil physico-chemical properties, such as particle size distribution, bulk density, porosity, moisture content, organic matter content, CEC and pH. The analysis of variance (F-ratio) and the students t-test were used to test for variations within and between the soil properties over the different land use types. Results of physico-chemical analysis showed that the soils in the study area are generally sandy (47.6% - 58%), have high bulk density (1.45 g/cm3– 1.6 g/cm3) and medium to low mean porosity values (38-45%). The mean moisture content is highest in Fadama land use and plantation (17.6%) and lowest within the degraded land (16.8%) and cultivated land (14.9%). CEC values over cultivated and badlands are low (at 4.26 cmol/kg-1and 4.31 cmol/kg-1 respectively). The differences in the soil organic matter content are statistically significant at the 0.01 level. The value is lowest over the badland (0.25g/kg-1) and highest over the plantation (1.77g/kg-1). Findings from this study showed that soils under cultivated and badland uses have higher bulk density, low porosity, moisture content, pH, organic matter content and CEC. These indicate pervasive levels of soil degradation which may be attributed to increased deforestation and continuous cropping in the study area. There is need for practical soil conservation measures for sustainable use of soil resources and incentives for rehabilitation of degraded soils.
© Department of Geography, Obafemi Awolowo University Ile-Ife, Nigeria 2016