A few warm days and we start feeling that spring is on its way. However, confinement site producers face another month with limits on land application to snow-covered or frozen ground. Switching to surface application increases the risks of runoff, and reduces available crop nitrogen.
Wet weather and cold weather left producers in some parts of the state heading into spring with nearly full storage structures. What can producers do to get manure hauled this spring?
Here are a few tips and requirements from Trent Lambert, supervisor of the Mason City DNR field office. Following these can help keep producers on the right side of Iowa’s manure application rules. All producers must follow some setbacks for surface application.
- Until April 2, snow-covered and frozen ground restrictions apply to application of liquid manure from confinements unless the liquid manure is injected or incorporated on the application date. They do not apply to small animal feeding operations (confinements with 500 or less animal units, e.g., 1,250 finishing hogs, 500 cattle, etc.).
- If you must switch from injection or incorporation to surface application before April 2:
Confinements must notify the local DNR field office that they need to do emergency application. Update the current manure management plan and apply only on fields identified for emergency application in the MMP.
Cover or block all tile intakes within and downgradient of the application area. The temporary intake blocks must be in place prior to land application and for at least two weeks following it.
Follow separation distance requirements for surface application. When surface applying liquid manure, a 750-foot setback is required from residences, certain other buildings and public use areas. For liquid and dry manure, a 200-foot setback is required when surface applying near most environmentally sensitive areas such as wells, sinkholes and water sources. Finally, high quality water resources need additional protection and have an 800-foot setback for surface application.
- Confinements, check your construction permit to see if your facility claimed points on the Master Matrix for injecting or incorporating manure. If covered by item 26e on the Master Matrix (footnote c), your operation must have a written waiver from a DNR field office before surface applying.
- Open feedlots, if you have a similar nutrient management plan under a federal NPDES permit or NRCS plan, check it to make sure it allows for surface application.
“Due to the weather last year, many producers are still facing manure management challenges early this year,” Lambert said. “One option is to surface apply just enough to get by until the weather breaks after April 1 and manure storage can be emptied.”
To prevent surface application runoff during freeze/thaw cycles, Lambert suggests picking the most appropriate fields:
- Flat or gently sloping
- Far from a stream or other water source
- Less vulnerable areas away from environmentally sensitive areas like wells, sinkholes or ag drainage wells.
And, remember to plug those tile intakes.
Find out more from a 2016 DNR news release or check out the latest Iowa Manure Management Action Group’s (IMMAG) update for 10 things to consider when winter manure application is necessary.