It’s important for cattle producers to understand the rules that apply to winter manure application. The law limits liquid manure application from Dec. 21 to April 1 if the ground is snow-covered. While there were some changes in the rules this past year, make sure you understand all the details before field applying manure this winter.

State law prohibits producers from applying liquid manure on snow-covered ground after Dec. 21, unless it’s an emergency. Those are producers with confinement (totally roofed) facilities that have 500 or more animal units. Generally, 500 animal units would be 500 steers, immature dairy cows or other cattle; or 357 mature dairy cows. 1,250 finishing hogs; or5,000 nursery pigs.

The law does not apply to manure from open feedlots or dry manure. “However, all livestock and poultry producers, regardless of size or type, need to protect water and prevent pollution as they land apply manure,” said Gene Tinker, coordinator of DNR’s animal feeding operations.

If manure can be injected or incorporated, it can be land applied during the Dec. 21-April 1 time period.

Questions about manure application can be directed to your local DNR field office. Here are field office locations and phone numbers.

Tinker said that if producers and commercial applicators are surface applying manure, they need to observe the separation distances. “The research shows that the later in the season and the closer to spring snowmelt that you apply, the greater the risk that manure-laden runoff will reach a stream,” he said.

The Iowa Manure Management Action Group at Iowa State University also has information about applying manure in the winter.

Source: Iowa Cattlemen's Association