Effects of Different Land Uses on Soil Quality and Degradation in Abeokuta, Ogun State, Nigeria

A detailed soil survey was carried out at the Teaching and Research Farms of Federal University of Agriculture, Abeokuta. The study aimed to determine the effects of different land-use types on some soil quality indicators and to examine the relationship among the land use types, soil quality indicators, and land degradation. Surface (0-15cm) and sub-surface (15-30 cm) soil samples were taken from different land-use types: Arboretum, Cashew, Oil palm (OP) and Fallow. Modal profile pits were dug depending on the land and soil types encountered. Profiles were described and sampled following standard guidelines. Soil quality indicators were assessed using a selection of soil quality indices including the bulk density (BD), total nitrogen (TN), potassium (K), magnesium, sodium, phosphorus (P), organic carbon (OC) and calcium. The extent of degradation was assessed using the direct approach method. Data were subjected to Analysis of Variance and means were separated using Duncan's Multiple Range Test at 5% level of significance. The results showed that Arboretum, OP and Fallow unlike Cashew had no significant(p<0.05) effect on BD, while TN was moderate in all the land uses. Phosphorus levels were low in all the land uses and not significantly different except in Cashew and OP. Direct observation showed that chemical deterioration was more severe than physical and biological degradation in all land use categories. In Arboretum, all the soils were minimally degraded with respect to BD and TN. All the soils were minimally degraded with respect to TN and 50% moderately degraded with respect to BD. In OP, 95% soils were only slightly degraded with respect to BD. However, in all the land use categories, the base saturation, potassium and phosphorus revealed high level of degradation. Land use, soil quality, and degradation.