Use of Nitrogenous Fertilizers and its Impact on Water Quality with Special Reference to Agricultural Development

Abstract

Water is an essential commodity of life on the earth. It plays a very important role in agricultural development. Agricultural activity impacts the water quality through the movement of chemical fertilizers and other poisonous materials from the agricultural fields to deep aquifers through surface runoff and deep percolation. The important source and cause of agricultural pollution are irrigational return flows and use of nitrogenous fertilizers in which nitrate is the basic component. High concentrations of Nitrate in natural water may cause methemoglobinemia, and have been cited as a risk factor in developing gastric and intestinal cancer. One of the most important negative effect of intensive use of nitrogenous fertilizer use is water eutrophication. Nitrates in the irrigational water serves as a nutrient to plants and crops. The agricultural water quality guide lines proposed by Ayers and Westcot (1994) mentions that the nitrate concentration ranges from 22.5 to 135 mg/l causes slight to moderate restriction and above 135 mg/l nitrate concentration causes severe restriction on crops for irrigational use. Due to the impact of fertilizers on human and environment, it is quite necessary to reduce the nitrate concentrations in natural waters to protected levels.