Hydrochemical evaluation of river Ajali water for irrigational application in agricultural farmland

Abstract A major population of Udi and Ezeagu communities residing along river Ajali is peasant farmers who engage in the cultivation of vegetables along the river banks during the dry seasons. The existence of beverage industries around the 9th Mile Corner Ngwo of Enugu State has caused both communities to suffer from a shortage of quality drinking water, due to the constant discharge of wastewater by these industries into the Ajali River, which flows through these communities. Ajali River water near some beverage industries was then assessed for irrigation application. Water samples were collected from different locations along the river. Physicochemical and ionic parameters were analyzed using standard methods. Irrigation water criteria were applied, and the result showed that the major cation and anions were Mg2+, Ca2+, Na+, K+and HCO3−, SO42−, $${\text{PO}}_{4}^{3- }$$ PO43- , NO3−, Cl−, CO3− .Na+was dominant with 43% average contribution of all the cations, while the least was Mg2+with 4% average contribution; HCO3−was the dominant anion with 31% contribution while $${\text{PO}}_{4}^{3- }$$ PO43- was the least with 2% average contribution. The trend of the cations was Na+ > K+ > Ca2+ > Mg2+while the anions were HCO3− > SO42− > Cl− > NO3− > CO3− > PO43−. The cation concentrations were within FAO irrigation water specifications. However, some samples recorded higher values of carbonate above FAO limit (0–3 mg/L). All the irrigation assessment criteria suggested that Ajali River water is suitable for irrigation purposes.