ABSTRACT
Soil nutrients, like all agricultural inputs, 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-N to groundwater through leaching. Surface water quality is the primary environmental concern with P, as runoff and erosion from fertile cropland add nutrients to water bodies that stimulate the excessive growth of aquatic weeds and algae. Best management practices for agricultural nutrients can vary widely from one region to another due to differences in cropping, topographic, environmental, and economic conditions. However, central to any nutrient management strategy would be an accurate assessment of nutrient need along with an accounting of on-farm nutrient resources such as manure, legumes, etc. The application of supplemental nutrients should be timed for maximum crop uptake and minimal chance of off-site movement. Nutrient management practices for optimizing crop production while protecting water quality are best summarized in a nutrient management plan that is regularly updated and tailored to the unique landscape characteristics and prevalent agricultural practices of individual farming operations.
