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Winter Manure Application Rules Kick in Monday Dec 21

  • 12/10/2015 8:50:00 AM
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DES MOINES – Early snowfall in much of northern Iowa may affect animal producers with confinement (totally roofed) facilities when limits on applying liquid manure on snow-covered ground start Dec. 21.

The statewide rules kick in then, because runoff and nutrient loss is more likely when manure can’t be injected into the soil or incorporated into a field.

Starting Dec. 21, confinement facilities with 500 or more animal units cannot apply liquid manure on ground covered with an inch or more of snow or one-half inch of ice. Generally, 500 animal units is equal to 1,250 finishing hogs; 5,000 nursery pigs; 500 steers, immature dairy cows or other cattle; or 357 mature dairy cows.

Except in emergencies, state law limits liquid manure application from Dec. 21 to April 1 on snow-covered ground unless manure can be properly injected or incorporated. Producers must call the local DNR field office to report emergency applications before they apply.

Starting Feb. 1, liquid manure application on frozen ground is restricted. 

While the law affects confinements with liquid manure, open feedlots and poultry producers can help keep manure in place by using common sense and choosing application areas far from a stream, on flat land with little snow cover.

All producers must follow setbacks from certain buildings and environmentally sensitive areas.

Find more information on separation distances and manure application at Look for recommendations from the Iowa Manure Management Action Group on applying manure in winter at