Suitability assessment of groundwater resources for irrigation around Otte Village, Kwara State, Nigeria

Abstract

The continuous decline in the quality of available surface water resources due to increasing global pollution threats, put pressure on the need for assessment of suitability of groundwater resources for irrigation purpose. This work assesses the physical and chemical characteristics of the local groundwater resources around the Otte Village, Nigeria, to determine its suitability for irrigation. The methods involve chemical analysis of the water samples obtained from 12 shallow hand-dug wells, and interpretation of the results based on acceptable guidelines. The results of the total dissolved solids (90 - 534 mgL -1 ), Electrical Conductivity (222 - 544 µS/cm), Soluble Sodium Percentage (-1.70 - 150.05 %), Permeability Index (4.15% - 22.57 %), Residual Sodium Bicarbonate (-1.89 - 5.63 meqL -1 ) and Sodium Adsorption Ratio (1.77 - 171.9) obtained for the water samples indicate that the geology appears to have greater influence on the chemical transformation of the groundwater resources, compares to any possible effects due to the anthropogenic activities. This work concludes that the water samples obtained from the areas underlain by the Migmatitic gneiss (W1 - W10) appear to be relatively suitable for irrigation compared with those underlain by the Granitic gneiss (W11 - W12). Further work is required to quantify the effects of the variability of the groundwater quality on the crop yield, as well as to assess any possible effects of the seasonal variations on the conclusions.