Kris Kohl, Ag Engineering Specialist
Spring manure application is a common practice in Northwest Iowa to utilize nutrients from livestock waste for corn production. Early spring when the ground has thawed is a good time to get the job done before planting. However, it is essential to follow best management practices (BMPs) to minimize environmental impact and optimize nutrient utilization. Here are some guidelines for spring manure applications:

1. Timing of Application: Apply manure when ground surface is dry where the crops will utilize the nutrients effectively, considering the crop nutrient needs. Use a manure management plan for manure that is coming out of a confinement with one. Avoid applying manure when the ground is frozen or saturated to prevent runoff.
2. Weather Conditions: Avoid application before heavy rainfall forecast that would lead to runoff. Three days of dry forecast after the application is preferable. Consider wind speed and direction to minimize odor drift to neighbors.
3. Manure Testing: Regularly test manure for nutrient content to adjust application rates accordingly. Because moisture content may be very different with stockpiled manure, test the sample before and during application. The before sample will allow a good estimate of the proper rate, while the test taken during the application will be what you get and can help with side dress adjustments. Use manure nutrient content information to determine the appropriate application rate for specific crops like alfalfa that use a lot of potash and phosphorus.
4. Record Keeping: Keep detailed records of manure application rates, dates, and locations. Document weather conditions during application. Incorporate manure into the soil to reduce odor and nutrient loss through volatilization.
5. Buffer Zones: Leave buffer zones near water bodies to reduce the risk of nutrient runoff. Follow setback distances specified in local regulations. Stay away from areas with a high risk of nutrient runoff, such as steep slopes or areas prone to erosion.
6. Education and Training: Train personnel involved in manure application on best practices. Even if you do not need a manure application license consider attending one of ISU’s manure applicators certification workshops. They are free to attend, and we go over all the current research and case studies. Stay updated on new technologies and research related to manure management.
   Adhering to these best management practices will help optimize the benefits of manure application while minimizing its environmental impact. Local regulations and guidelines may vary, so it’s crucial to stay informed and comply with specific requirements in your area.