ABSTRACT
Soil nutrients need to be managed properly to meet the fertility requirements of crops without adversely affecting the quality of water resources. The nutrients of greatest concern relative to water quality are nitrogen (N) and phosphorus (P). Nitrogen not recovered by crops can add nitrate to groundwater through leaching. Nitrate is the most common groundwater contaminant found in the United States.[1,2] Nitrate levels that exceed the established U.S. drinking water standard of 10 ppm nitrate-N have the potential to adversely affect the health of infants and livestock.[3]
Surface water quality is the concern with P, as runoff and erosion from cropland add nutrients to water bodies that stimulate the excessive growth of aquatic weeds and algae. Of all crop nutrients, it is critical to prevent P from reaching lakes and streams since the biological productivity of aquatic plants and algae in fresh water environments is usually limited by this nutrient.[4] Consequences of increased aquatic plant and algae growth include reduced aesthetic and recreational value of lakes and streams as well as the seasonal depletion of water dissolved oxygen content, which may result in fish kills as well as other ecosystem disruptions.
