Study of groundwater quality has been undertaken in Ogbia, Bayelsa State, Nigeria to assess the suitability of groundwater for irrigation. Knowledge of the effect of irrigation water on soil properties is very important in the area in order to maintain good soil productivity. This study therefore is aimed at determining whether the groundwater in the study area can be used for agricultural purposes. The research was based on the result obtained from the calculated Sodium Adsorption Ratio (SAR). The SAR is the most useful parameter used in the determination of the suitability of the groundwater of any area for agricultural purposes. The calculated SAR for groundwater ranges from 3I.06 to 65.23mg/l, indicating that the groundwater samples, showed low salinity and very high sodium water for irrigation purposes for most soils and crops with danger of development of exchange sodium and salinity. This shows that the groundwater samples are not suitable for irrigation. High SAR values (>I0) could cause sodium to replace adsorbed calcium or magnesium, thereby damaging the soil structure.
Keywords: Coastal aquifer, Groundwater, Irrigation Water, Salinity, Sodium Absorption Ratio
