Fall Manure Application – Environmental and Personal Safety Considerations

This article presents considerations for fall manure application to help retain nutrients on site and ensure all workers remain healthy throughout the hauling season.

Let's start off by looking ahead. Considerations for spring manure handling should begin in early fall. Manure applications in the fall will help to determine storage capacity later, should winter weather linger longer than expected. A smart, well-planned application in the fall may prevent a hurried, stressful application in the spring, when weather and soil conditions pose a high risk of nutrient loss.

Every producer should be aware of storage capacity, both in volume and in time, for both liquid and solid manures. Know how many months or weeks it takes to fill your storage. Safe planning should allow manure to accumulate without removal to the field until the end of March, or longer. To accomplish this, consider emptying the storage this fall. For liquid storages, accumulation of solids can rob you of precious storage space and time. If solid buildup currently exists in your storage, make efforts to agitate and remove it. Routinely monitor and record your storage depth.

Fall and winter are seasons when prioritizing the location of manure application is critical. It is best to place the nutrients on (or in) the soil where they will remain until plant uptake. Ideal lands are those that have a crop that will grow through the fall, such as hay or an established cover crop. Ground cover is important. Crop residue or growing plants should cover at least 25% of the soil surface. The residue helps to hold nutrients, prevent runoff and erosion, and increase infiltration.

Looking ahead also means thinking about winter, which is defined in Pennsylvania as:

• calendar dates between December 15 and February 28, or
• ground is frozen 4 inches or deeper, or
• any amount of snow is on the field.

Risk is elevated when soil is snow-covered, frozen, or saturated. Care should be exercised. Every field that receives winter manure application must be identified in a nutrient or manure management plan. These identified fields must contain a proper groundcover of 25% or more, or an established cover crop. Setback distances from surface waters and wells are 100 feet in the winter, unless the farm's plan specifically allows closer application.

Please think of the task ahead not as manure application, but rather as manure nutrient placement. Place manure nutrients at a location and in a manner that will keep them available until they can be taken up by the desired crop. If the nutrient moves, then the effort did not meet agronomic and environmental goals. If you know nutrients move after placement, then a management change is needed. This is an area where experience with your land can pay off. An honest evaluation of historical occurrences on the land during dormant months will help identify areas within fields, or entire fields, where runoff risk is greater. These may be very small areas, such as a swale or steep hillside. Challenge yourself to keep every precious manure nutrient component where you place it.

Always pay attention to safety. It is everyone's responsibility to ensure the safety of workers, visitors, livestock, and especially children. Remember that complacency kills. An unseen danger exists when gases are released from manure. The gas of largest concern is hydrogen sulfide, which can be deadly at modest concentrations. However, any gas can be deadly if it displaces oxygen. The risk of gas exposure is greatly increased when manure is agitated or moved. Both liquid and solid manures can release gases at hazardous levels.

It is highly recommended that manure handlers wear a gas monitor. These monitors will give an alarm when dangerous gas levels are reached. Monitors can be purchased or rented. Pay attention to your body and move to fresh air at the slightest sign of gas exposure. We call these triggers Body Alarms, and they include respiratory discomfort, headaches, dizziness, loss of motor skills, anxiety, and severe irritation of thethroat or eyes. Shut down agitation processes if exposure is suspected and move immediately to fresh air. By all means avoid confined spaces, but keep in mind that many exposure incidents occur at outdoor, open-air storages. Have a safe application season.