Irrigation Water Characteristics, Their Correlations and Suitability for Agriculture in District Gujranwala (A Survey Study)

Abstract
| A survey study was conducted in Gujranwala district to evaluate the quality of groundwater for agriculture purpose. A total of 565 groundwater samples were collected from farmers’ tube wells during random survey of four tehsils of Gujranwala district, i.e., Gujranwala, Kamoke, Wazirabad and Noshera Virkan. The water samples were analyzed in Soil and Water Testing Laboratory Gujranwala for electrical conductivity (EC), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), chloride (Cl) and sodium (Na) of the groundwater. The results revealed that out of 565 samples, 231 (41%) were fit; 149 (26%) were marginally fit, and; 185 (33%) were unfit regarding their quality. The maximum samples were found unfit for high RSC followed by EC and combined effect of EC and RSC, implying that use of such groundwater for irrigation may be a cause of salinity as well as sodicity for soils of the district. The ‘maximum values’ of Cl ion and ‘mean values’ of Na ion were observed higher than their permissible values (4 me L -1 and 3 me L -1 respectively) in all the four tehsils, indicating that groundwater is toxic to crop growth at certain locations of the district. The data manifested that the quality deciding parameters i.e., EC, SAR and RSC of irrigation water were statistically positively correlated (p <0.01) with each other having coefficient of correlation r = 0.685, 0.540, 0.597 for EC; SAR, EC; RSC and SAR; RSC respectively. From these results, it was concluded that RSC is the major factor for unfitness of water quality in Gujranwala district followed by EC and SAR, whereas, toxicity of groundwater to crop growth due to Cl and Na ions is also worth-considering.