Water quality for irrigated-rice-based cropping system in the Oda river valley bottom at Besease, Ghana

Abstract

The Valley Bottom Rice Development Project was started in Ghana in 1990 under the Agricultural Sector Rehabilitation Programme of the Ministry of Food and Agriculture To assess the quality of river and shallow groundwater for irrigation at the Besease project site, physico-chemical analysis were carried out from 1994 to 1997 and the results were evaluated The total dissolved solids (TDS) of river water ranged from 6000 to 26000 mg 1''-1,with a mean of 11799 mg 1''-1,and that of groundwater ranged from 9500 to 48200 mg 1''-1with a mean of 2978 mg mg 1'-1 The adjusted sodium absorption ratio (ASAR) of river water ranged from 008 to 028 with a mean of 012, and that of groundwater ranged from 024 to 262 with a mean of 172 Based on these and other measurements, both river and shallow groundwater are suitable for irrigated rice farming in the Oda river valley bottom at Besease However, the study indicated excess bicarbonate (HCO3'-)content of groundwater (mean: 1624 meg 1''-''1), capable of reducing the yield and quality of rice (au)