Source: Cooper, C.M., and W.M. Lipe. 1992. Water quality and agriculture: Mississippi experiences. J. Soil Water Conserv. 47:220-223.

Water quality, which is an increasingly important issue, is directly affected by agricultural practices. Runoff from agricultural land flows directly into lakes and streams, carrying with it contributors to water pollution. There are four main sources of water pollution that will affect the quality of freshwater reserves in the future. Sediments are the most prevalent cause of water pollution, for they represent a more general form of pollution and often contains significant amounts of the three following contaminants: nutrients, pesticides, and coliform bacteria. Nutrients from heavily fertilized cropland and stock wastes are lost to runoff or through improper treatment of animal wastes. Nitrogen and phosphorus limit aquatic productivity in nutrient-deficient freshwater lakes and streams. Excessive amounts of nutrients will lead to algal blooms and eutrophication. Pesticides are the third water pollutant. When carried to lakes and streams, pesticides become one of the leading causes of aquatic plant and animal life destruction. Organochlorine insecticides are among the leading causes of fish deaths. The insecticide DDT, though banned years ago, continues to pollute water reserves. It is transferred as runoff from the water-shed soils in which it is present. Coliform bacteria are the fourth source of water pollution, originating from both point and non-point sources. As non-point sources, coliform bacteria present in animal manure are transmitted to water sources through runoff from feedlots, pastures, and land disposal areas. As a point source, coliform bacteria are transferred to streams through direct animal contact with the water. Soil sediments in stream bottoms tend to accumulate large amounts of coliform, producing a threat of pollution when present. These origins of water pollution from agricultural lands can be controlled through strict management measures. The authors point out that provisions such as erosion control, runoff detention, treatment of non-point-source discharge before it leaves the land, integrated pest management, banding application of fertilizers, and limiting livestock access to streams will help reduce water pollution from agricultural lands and help secure the quality of water in the future. 

Abstract author: Mariah H. Roof, 25 October 1998.

SUSAG Abstracts: Go back to the SUSAG Abstracts search page.