Effect of Irrigation Water Quality on Soil Structure Along Asa River Bank, Ilorin Kwara State

Good soil structure is an essential element of healthy and sustainable agroecosystems. It promotes the development of extensive plant root systems and efficient use of water and nutrients. An experiment was carried out with the objective of evaluating the effect of irrigation water quality on soil structure, it was conducted in a two way factorial with four (4) locations selected along the river (0m, 200m, 400m and 600m) as factor A, and four (4) farmers' plots were selected based on the years of irrigation (0, 10, 20 and 30 years) as factor B while three (3) farmers plots with similar irrigation history were used as replicates, with this arrangement 12 plots were selected in each farming location giving a total of 48 plots from which soil samples were taken for analysis. The mean concentration of the parameters were pH (7.09-7.82), Electrical Conductivity {EC} (0.09-0.14), Sodium Adsorption Ration {SAR} (0.12-0.74) Exchangeable Sodium Percentage {ESP} (3.59-9.46), Sand (74.67- 82.10), Silt (11.28-16.67), Clay (6.89-11.06), Mean Weight Diameter (1.38-1.53), Bulk density (1.12-1.29), Porosity (51.26-54.08), Saturated Hydraulic Conductivity (1.18-3.57).The mean concentration showed increase as the water flow downstream while higher value observed at location 3 (400m), the collected soil samples were subjected to analysis of variance using randomized complete block design (RCBD) at 5% probability level. The result showed that all the parameters were in a safe range when compared with WHO (2005) and FAO (2007) standard. It was recommended that effluent discharge and dumping of refuse along the river channel should be forcefully discouraged and that government should help in providing household disposal sites for the inhabitants of the town and that regular monitoring of Asa river be carried out as there is notable increase in the level of human and industrial activities along the course of the river.