Assessment of groundwater quality for irrigation purpose in parts of Nalgonda district, Telangana (India)

The main focus of this study is to assess the suitability of groundwater quality of Suryapet area of the Nalgonda district for agricultural purpose on the basis of hydrochemical data. Based on the analytical results, pH of water is found to be alkaline in nature; ninety percent of the TDS samples falling under medium hazard to high hazard salinity category, which may be unacceptable for irrigation. Hundred percent of samples exceed the threshold limit of 150 meq/l of total hardness for irrigation purpose. As per U.S. salinity classification, medium, high and very high salinity categories were observed. According to trilinear diagram, hydrochemical facies are classified as (i) Na+ - Cl-, (ii) Na+ - HCO3- and (iii) HCO3- -Cl- types. High chloride content due to anthropogenic activities in the village and industrial areas, led to the presence of a critical level of chloride in water that is being used for irrigation. In the case of bicarbonate, eighty-five percent of the samples indicate a severe problem to soil permeability, which is not in conformation for their suitability for irrigation. However, the Sodium Adsorption Ratio (SAR) parameter indicates the suitability of water for use in agricultural irrigation and also in the management of sodium affected soils. The suitability of water for irrigation in clay soils is identified by using the RSC index. SAR and RSC values show that the groundwater is fit for irrigation utility, most of the Permeability Index values plotted in the class-II category with the permeability of 25% - 75%, are marginally safe and good for irrigation. Wilcox diagram shows, eighty percent of the samples plotted in the class are doubtful to unsuitable. Sixty percent of Kelly's, Magnesium Adsorption Ratio values indicate adverse affect on the crop yield by making the soils more alkaline. Hence, the majority of the studied parameters, indicate that the groundwater may not be fit for the above-said purpose.