Hydrochemical Assessment and Irrigation Suitability Analysis of Ikpoba River Water

This study assesses the irrigation potential and suitability of Ikpoba River by combining water quality analysis, hydrochemical character and advance statistical assessment and evaluation. Water samples collected were analyzed for physicochemical parameters, major cations (Na⁺, Ca²⁺, Mg²⁺, K⁺), anions (Cl⁻, HCO₃⁻, SO₄²⁻) and heavy metals. Irrigation suitability was evaluated using standard indices such as Sodium Adsorption Ratio (SAR), Kelly’s Ratio (KR), Percent Sodium (%Na), Gibb’s plot, Piper’s plot, Wilcox plot, Residual Sodium Carbonate (RSC), Magnesium Absorption Ratio (MAR) and Permeability Index (PI). Results indicate that Ikpoba River water is broadly suitable for irrigation for many crops but possessed localized increases in salinity and sodium hazard. With approximately 58% of %Na value, and as one of the major cations of the water is a waterquality sodium indicator, the water samples fall in doubtful near-unsatisfactory range for sodium hazard to soils and crops, as a result if used for irrigation the water could cause infiltration or structure problems over time. Also, Kelly’s ratio of > 1 indicates excess sodium hazard for irrigation, by these indices, these waters would be considered not suitable for irrigation. The study recommends that if this water should be used for irrigational purpose there should be the need for soil amendments to blend the water with lower-Na water, apply gypsum (CaSO₄) to improve Ca:Na balance in soil, also routine monitoring, adoption of appropriate crop selection, drainage practices and integrated catchment management to protect long-term irrigation viability. These findings provide a baseline for sustainable irrigation planning in the Ikpoba basin.