Michigan State University Extension
Soils & Soil Management - Fertilizer - 06109722
07/10/97
Nutrient Management to Protect Water Quality Extension Bulletin WQ-25, January 1996
Maurice L. Vitosh and Lee W. Jacobs Extension Soil Specialists Department of Crop and Soil Sciences Michigan State University
Many management strategies exist for achieving effective and efficient use of nutrients without risk of reducing yield or contaminating water resources. Here are several important management practices that crop producers should follow:
1. Soil test every two to three years and follow MSU fertilizer recommendations.
2. Choose a realistic yield goal that can be achieved 50 percent of the time.
3. Take credit for nutrients supplied by organic matter, legumes and manure or other biological wastes containing nutrients. Manures and other wastes should be tested to determine the amounts of nutrients they can supply.
4. Where leaching is a serious problem, use ammonium forms of fertilizer to reduce nitrate N losses.
5. Avoid fall applications of N on all soils where winter and spring precipitation can cause runoff or leaching.
6. Use delayed or split applications of N to prevent excessive leaching of nitrates on sandy soil.
7. Use soil nitrate tests to determine residual nitrate and recently mineralized nitrate to estimate N credits for reducing N fertilizer recommendations for corn.
8. Consider using nitrification inhibitors when it is not feasible to use delayed or split N applications.
9. Consider using plant analysis to determine how well you have done in supplying crop nutrients.
10. Consider using crop rotations rather than monocultures to reduce the need for N and assist with pest control.
11. Use cover crops and forages to prevent wind and water erosion and excessive loss of N to groundwater.
12. Check nutrient application equipment for proper calibration.
13. Keep good records of soil test results and plant nutrients applied to demonstrate that good management practices are being followed.
14. Use modern irrigation scheduling techniques to avoid applying excessive amounts of water that could leach nitrate N below the rooting zone.
15. Develop a whole farm nutrient management plan, particularly for livestock operations that generate manure nutrients. Planning for best utilization of all available nutrients - whether from manure, soil organic matter, legumes or fertilizers - will return economic benefits as well as reduce risks to water quality.