Utilization of Shallow Aquifers for Small Scale Irrigation: A Case Study of Agatu Local Government Area of Benue State, Nigeria

Abstract

Agatu Local Government Area of Benue State has a floodplain totalling about 25,000 hectares composed of recent alluvial deposits. There are fifteen exploratory wells developed in the area by Benue State Agricultural and Rural Development Authority (BNARDA). This study carried out standard pumping and recovery tests on the wells and determined the yield of each well. The yields were compared with the crop water requirements of selected crops. Four simple methods of tubewell drilling of shallow aquifers were also comparatively evaluated on the basis of cost and related criteria to see which one is most suitable for the area. The values of the well yields ranged from 1.5l/s as the lowest to 5.0 l/s as the highest with a mean of 2.95l/s. Based on the crop water requirements of selected crops, the yield of each tubewell is more than sufficient to adequately irrigate one hectare of land. The cost of drilling a tubewell using the clear water jetting method was found to be 47%, 72% and 77% of the cost of using the rotary rig, the mud washboring and the baildown methods respectively. Therefore, economically the clear water jetting method is hereby recommended as the most suitable for the study area, especially as it suits the geology of the area very well. With encouragement from Governmental and non-governmental organisations in provision of inputs and credit facilities, the rural farmers in the locality can be gainfully employed in irrigated agriculture during the dry season as against the current practices where they do little or nothing.