Suitability of Groundwater Quality for Irrigation

Reconnaissance on the suitability of groundwater quality for irrigation in Tubinakere industrial area, Mandya district, Karnataka was done by determining ion exchange, potential salinity, Cl^-/HCO₃^- ratio, magnesium hazard, percentage sodium, Kelley’s ratio and Residual Sodium Bi-Carbonate (RSBC). 94% of the samples are positive in case of both cation exchange indices leading to reverse ion exchange, potential salinity is slightly high making groundwater samples unfit for irrigation purpose. 75% of samples are slightly to moderately affected on the basis of Cl^-/HCO₃^- ratio. Two of samples falls in unsuitable category with Magnesium Hazard >50%. Based on the classification of percentage sodium, maximum of samples falls under excellent, good waters and 87% of samples were suitable for irrigation as per Kelley’s ratio. RSBC values were <5meq/L safe for irrigation purposes. The study stated that water quality hazards of potential salinity and ratio of Cl^-/HCO₃^- values indicates that groundwater samples are not suitable for irrigation.

Keywords: Industrial effluent, irrigation, sodium, impact.