The Effect of Agriculture on Quality of Groundwater: A Case Study

Abstract

The study was focused on quality of groundwater in different cropping system. Groundwater samples were collected from different cropping systems and an analysis was done periodically from July 2007 to February 2008 for important chemical parameters; nitrate-N, electrical conductivity, pH and chloride. Totally sixty eight wells were selected randomly from different cropping systems such as high land crops, mixed crops, banana and paddy field. The nitrate-N content was determined colorimetrically using the brucine method. The pH and EC of the collected water samples were digitally measured by using pH meter and conductivity meter respectively. Mohr’s titration was used for determination of the concentration of chloride. Results reveled that there was a good correlation between cropping system and nitrate-N concentration in groundwater. High nitrate-N concentration of groundwater was observed at high land crops land use followed by mixed crops and there was no significant difference between high land and mixed crops. Concentration of nitrate-N in paddy and banana land use was less than the recommended level of 10 mg/L. There was significant different between high land and mixed crops to banana and paddy land use. But there was no significant difference between paddy and banana. There was no correlation between land use and electrical conductivity, pH and chloride in groundwater. It is worthy to note that the level of nitrate-N concentration of water was influenced by cropping system.