Assessment of Soil Fertility Status under Continuous Irrigation Farming in Nigerian Savanna
This study assesses soil fertility status under continuous irrigation farming in Nigerian Savanna. Soil samples were collected from eight irrigated farm plots in Zaria while adjacent uncultivated soil was used as the control. Soil samples were collected from 0-20cm (topsoil) and 20-50cm (subsoil). 108 soil samples were collected and analyzes using standard laboratory methods. Soils were analyzed for texture, bulk density, porosity, moisture content, Soil pH, Organic matter, total
nitrogen, available phosphorus, exchangeable bases (Ca, Mg, K, Na), exchangeable acidity (H+Al), exchangeable cation exchange capacity (ECEC) and base saturation. Descriptive statistic was used to compare the results while Pearson Correlation Coefficient was used to test the elements at 0.01 and 0.05 alpha levels. From the result, the textural grades are loamy. The mean values obtained for each elements at the irrigated plots are: sand (50.38%), silt (39.63%), clay (10%), bulk density (1.38), porosity (47.75%), moisture content (0.26cm3), pH in water (5.44) and
in CaCl2 (5.7). organic matter 1.74%, total N 0.12%, available phosphorus (58.36cmol/kg-1), cations (Ca (7.76cmol/kg-1), Mg (1.48cmol/kg-1), K (0.36cmol/kg-1), and Na (0.61cmol/kg-1), H+Al (0.59cmol/kg-1), ECEC (10.62cmol/kg-1) and base saturation (93%). The control plot showed better improvement in terms of both soil physical and chemical properties. It is recommended that soil testing should be carried out from time to time to monitor the rate of soil deterioration under continuous irrigation.