Water quality is affected by nutrient management when chemicals, soil, and residue move off of agricultural land or below it. This section focuses on a number of production issues that when managed correctly minimize the potential for off-site consequences because excess of the nutrients is limited or eliminated.

It is difficult to separate the knowledge and decision making processes that are needed for efficient and profitable crop production compared to those needed to maintain water quality. For the most part, they are similar. Therefore many of the documents and resources cited here are links to materials available elsewhere.

As a general rule, nitrogen is mainly a threat to groundwater and phosphorus is associated with surface water contamination. Other nutrients such as potassium, zinc and sulfur are not considered threats to water quality, at least in regard to the consequences of agricultural application. Other topics to be addressed include:

• Application timing
• Placement
• Additives/inhibitors
• Fertilizer sources
• Site-specific management
• Managing Irrigation and Nitrogen for Water Quality

Information presented within the crop nutrient management section of this Water Web site has been reviewed by University of Nebraska - Lincoln Cropping Systems Team members Richard Ferguson and Charles Shapiro.