Dry conditions and warm weather provided an early harvest and manure application season. But here are a few reminders, if winter application is still necessary.

Confinements with liquid manure--restrictions start Dec. 21

Runoff into our streams is more likely to occur during winter manure application. State law limits liquid manure application for confinement operations (roofed facilities) with more than 500 animal units.  Restrictions on applying manure to snow-covered ground began Dec. 21 and continue until April 1. Liquid manure cannot be applied to fields covered with 1 inch of snow or 0.5 inches of ice, except in an emergency.

Starting Feb. 1, applying liquid manure on frozen ground is also restricted until April 1. Call the local DNR field office prior to any emergency application. Be sure to update your manure management plan records.

Other limits may apply if you took credit for injection or incorporation as part of a construction permit application using the Master Matrix.

Winter land application of liquid manure from confinements is allowed when producers can inject or incorporate manure on the same date, and when the ground is not frozen or snow-covered.

Rules for all producers

While limits on winter land application do not apply to open feedlots, dry manure and small confinement producers, all producers must prevent water quality violations. Often they can help protect water quality by using common sense, and choosing application areas far from a stream on flat land with little snow cover.

All surface land application must follow setbacks from buildings and environmentally sensitive areas. Look for more information on winter application rules on DNR’s animal feeding operations webpages. When winter application is necessary, find 10 more tips for safe application in the Iowa Manure Management Action Group’s November 2019 newsletter.