The doodoo and don'ts of spring manure application

While spring is quickly approaching, it’s important for farms to take steps now to help them be prepared for this spring’s manure application. Spring weather in Wisconsin is unpredictable, making it tricky to have ideal application conditions and leaving only a small window for success. Thus, these conditions make patience and timing imperative as waiting too long to apply manure can be detrimental.

Since spring is inevitably a busy time in agriculture, it’s always important to properly prepare for spring manure applications. Being prepared ensures proper nutrient application rates and compliance with manure application regulations, prevents nutrient losses, and streamlines the overall application process.

While you may know where and how you are going to apply your manure, here are some tips to keep in mind to ensure proper and effective spring applications of manure.

1. Inspect and calibrate your equipment. Whether you are spreading liquid or solid manure, checking the equipment is important for avoiding equipment failure and spills. Even during application or heavy use it is important to monitor the equipment for leaks or wear and tear and fix any issues before it becomes a larger problem.
2. Get manure sampled and analyzed. Manure is a very valuable fertilizer source and knowing the nutrient content can help maximize fertilizer savings. Be sure to collect representative (composite) manure samples and submit to a certified lab for nutrient analysis – including Nitrogen (N), Phosphorus (P), and Potassium (K). Sample collection varies by manure type so check with your laboratory for proper sampling techniques.
3. Determine the appropriate manure application rates for each field. Rates should be based on the needs of the upcoming crop (UW Recommendations), recent soil tests, and the nutrient content of the manure. Typically, nutrient application rates are based on nitrogen or phosphorus content of the manure. It’s also important to take into account any legume credits or fall manure or fertilizer application rate.
4. Determine the location of any buffers or setbacks. This would include determining the location of buffers for sensitive areas like surface water, personal and community wells, drainage areas, and tile lines. The maps within your nutrient management plan are the first place to start.
5. Monitor the weather forecast. If you must apply during less than ideal conditions, select low risk fields noted in your nutrient management plan to reduce the risk of nutrient loss. These fields may have minor slopes (or be flat), perennial cover or cover crops, fields with heavy crop residue, and fields further from surface water. Fields should be prioritized based on risk factors, starting with least risky fields and finishing with the most risky fields. It is also important to avoid manure applications when significant rain is in the forecast. Nutrients lost off the field increase future fertilizer expenses and impact farm profitability.
6. Do not apply manure to very wet or saturated fields. Applications of nutrients during very wet, snow-covered, or frozen conditions can lead to an increased risk of nutrient loss. These field conditions slow infiltration and can contribute to increased runoff of manure and nutrient loss. Avoid manure application in areas of fields where water gathers and flows, as this carries nutrients off the field.
7. Apply manure to fields according to calculated rates. Do not over apply manure! Over-application of manure can lead to higher rates of nutrient loss that can end up in water bodies and cause declines in water quality.
8. Keep records of applications. It is important to record the date, field location, acreage, manure source, and the amount of manure applied.

It benefits you to spend time communicating with neighbors who may be impacted by manure application. Depending on the situation, it might be helpful to connect with neighbors and discuss planned upcoming manure applications and determine any days that application may be avoided. Remember, wind speed or direction could impact neighbors during application, and keeping neighbors informed can help reduce complaints and mitigate negative attitudes toward manure spreading.

For more information please visit the University of Wisconsin Integrated Pest and Crop Management website (ipcm.wisc.edu) for the latest in pest and nutrient management news, information, and research.

Schuler is the Southeast Regional Outreach Specialist, Nutrient and Pest Management Program University of Wisconsin – Madison