当前世界环境

The assessment of water qualities for irrigation in river Katsina-Ala catchment areas of Benue State was carried out. Surface water and groundwater samples from three selected catchment areas namely, Logo, Ambighir and Katsina-Ala, were collected and analyzed for physicochemical parameters. Several soil samples were also analysed for infiltration capacity. All the physicochemical parameters monitored fell within FAO specifications for irrigation purposes. Groundwater samples were found to have higher concentrations of physicochemical parameters than surface water. On the basis of hydrochemical classification, earth alkali types were dominant (100%) in both groundwater and surface water samples while the alkali type was totally absent. Assessment of the water samples for irrigation showed that the water samples posed no problems with regard to sodicity, salinity and lime deposition. However, high risk of infiltration was envisaged as a result of very low values of conductivity (0.03ds/m – 0.13ds/m). At the present, infiltration problem is minimal because of high proportion of sand (68% - 89%) in the soils but this situation may not be sustained for long. A regression model (R = 0.773) was obtained which showed that the rate of infiltration strongly depended on the sand content of soil. Both water and soil samples were found to be suitable for a wide range of irrigation.