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CE 521 Environmental Biotechnology

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The Effects of Non-Point Source Agricultural Fertilizer Contamination on Water Resources 

Ben Bobzien

Abstract

Non-point source contamination of water resources by agricultural fertilization is a large problem in America and around the world.  Some of the highest losses of nitrate, and phosphorus come from agricultural land.  It is necessary for farmers to apply an excess of fertilizer to the soil due to the fact that crops only uptake about 50% of the applied nutrients (Liu and Hallberg, 2002).  The effects of nitrate contamination include eutrophication, human illness (e.g. methemoglobinemia, and cancer).  Phosphorus contamination is also associated with eutrophication problems.  The farmer will always wish to apply more fertilizers to the soil, than what is acceptable to state water quality standards.  Here lies a conflict between the state and the farmer.  Many studies have been conducted to determine the effects of agricultural contamination of water resources.  These studies include, remedial measures, pathways of nutrient leaching, economical analysis’s of fertilizer application, sludge application, and best management models.  Application of waste water treatment plant (WWTP) sludge adds N, P and heavy metals to the soil.    Phosphorus was used in small quantities by the plants, and was found to accumulate in the soil after repeated applications.  Thus P was found to be the limiting factor in application of waste water treatment plant sludge.  Remedial methods include constructed wetlands, denitrification by electromagnetism, or biodegradation by direct treatment.

Keywords:  Agriculture pollution, Non-point source contamination, Nitrate, Phosphorus, Water quality, Water pollution 

 

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