Suitability Evaluation of River Owan Water for Irrigation

Abstract

Water samples from River Owan located within the Benin-Owena River Basin, southwestern Nigeria, were investigated for irrigation suitability employing electrical conductivity (EC), Sodium Absorption Ratio (SAR), %Na, Residual Sodium Bicarbonate (RSBC), Potential Salinity (PS), Soluble Sodium Product (SSP), Magnesium absorption ratio (MAR), Kelly ratio (KR) and Wilcox plot. Estimated irrigation parameters revealed that SAR ranged from 0.15 – 1.4 (av. 0.33), RSBC; -1.75 – 2.68 (av.0.73), MAR; 36.86 – 77.41 (av. 60.11), KR; 1.69 – 8.37 (av. 3.06) while PS, SSP and %Na were from 0.01 – 3.12 (av. 0.56), 31.51 – 70.33 (av. 55.99) and 19.93 – 58.69 (av55.99) respectively. Furthermore, Wilcox plot revealed that all water samples from River Owan were in the excellent to good irrigation category. All estimated indices except MAR and KR indicated that River Owan water was suitable for irrigation. Wells at Owan were shallow and pruned to dryness during dry season. River Owan water that was moderately suitable for irrigation could serve as a buffer to farming activities especially during dry season.