(DES MOINES) Most animal and crop producers know there is greater potential for runoff and nutrient loss following winter manure application. State law, however, sets some dates when producers with confinements can, and can’t, apply liquid manure on snow-covered or frozen ground.
The law does not apply to manure from open feedlots or dry manure, or in the case of emergencies. It does apply to confinement (totally roofed) facilities with liquid manure that have 500 or more animal units. Generally, 500 animal units would be 1,250 finishing hogs; 5,000 nursery pigs; 500 steers, immature dairy cows or other cattle; or 357 mature dairy cows.
The law limits liquid manure application from December 21 to April 1 if the ground is snow-covered. If manure can be properly injected or incorporated, it can be land applied during this time. Snow-covered ground is defined as soil having one inch or more of snow cover or one-half inch or more of ice cover.
Starting February 1, confinement producers with 500 or more animal units will also be limited to emergencies if applying liquid manure on frozen ground. The rules are available online under Chapter 65 of the Iowa Administrative Code/Environmental Protection Commission.
Emergencies are defined by state law as unforeseen circumstances beyond the control of the producer such as natural disaster, unusual weather conditions, or equipment or structural failure.
Producers must call the local DNR field office before they apply to report emergency applications. They can apply manure only to fields identified for emergency application in the manure management plan that have a Phosphorus Index of 2 or less. DNR field specialists may have ideas or suggestions for producers on specific sites or risks.
Field office locations, phone numbers and information are available on the DNR website.