Effects of large scale irrigation on drinking water quality in the Bukhara and Kashkadarya provinces of Uzbekistan

This article presents the results of a study on the effects of farm practices on drinking water quality in the Bukhara and Kashkadarya provinces of Uzbekistan. These two provinces are the largest irrigation districts in Uzbekistan and, in 1999, withdrew more than 10 cubic kilometers. (km(3)) of irrigation water from the Amu Darya River Cotton is the major irrigated crop grown in these districts and has required the application of large quantities of fertilizers and pesticides. These irrigation practices resulted in 2 km(3) of discharge water draining directly into the Amu Darya River and an equal amount of discharge water draining into natural lowlands in the region. Drinking water quality has worsened dramatically because of these discharges. The main pollutant components originated from mineral fertilizers and chemicals, which were applied on the irrigated lands. The amount and type of chemicals present in the drainage water can be linked to the agricultural production systems in the region.