The arrival of cold weather, snow and ice means Indiana's livestock producers need to remember that applying manure to farm fields during the winter is regulated by the state.

Frozen ground during the winter months can make manure application a more risky endeavor, said Tamilee Nennich, Purdue Extension nutrient management specialist.

"There's potentially an increased risk for nutrient runoff in winter," she said. "Ideally, manure nutrients should be incorporated into the soil to ensure they make contact with the soil, which may not happen if manure is applied on frozen or snow-covered ground."

Because of the runoff risk, the state of Indiana regulates when producers with permits for concentrated animal feeding operations and confined feeding operations can apply nutrients. Manure from CAFOs or CFOs cannot be applied to frozen or snow-covered ground.

The only exception is for emergency situations, such as extreme weather events. Producers facing an emergency must contact the Indiana Department of Environmental Management to seek a temporary exemption before applying manure.

 "I want to remind producers that exceptions are only for emergency situations - not for standard operating purposes," Nennich said.

Another important rule for livestock producers to be aware of is the Indiana Fertilizer Material Use rule, which went into effect in February 2013.

"This rule is very important because it applies to any producers applying manure during winter - not just large operations," Nennich said.

According to the rule, anyone applying manure when the ground is frozen or snow-covered needs to ensure they are applying it:

  • At half or less of the agronomic rate of the planned crop.
  • To ground with less than 2 percent slope.
  • To ground that has at least 40 percent of a cover crop or crop residue.
  • At least 200 feet away from any surface water.

More information about the fertilizer rule can be found at http://www.oisc.purdue.edu/fertilizer/pdf/fert_use_rules_and_faq.pdf.

Nennich encouraged producers who need to apply manure in the winter to apply it using best management practices and when there's good weather.

Producers also need to keep records of manure application, including when it's applied, the field and acreage where it's applied, the source of the manure and how much manure is applied so they can calculate the nitrogen and phosphorus application rates applied to the field. For permitted operations, records are required. And while they aren't mandatory for smaller farms, Nennich said they are still essential.

"Keeping detailed records is really important for operations of any size," she said. "Nutrient management records are the only way producers can prove that they have made every possible effort to protect the environment."

Each year, Purdue Extension publishes the free Nutrient Management Record Keeping Calendar. The 2014 edition will be available in January at various Purdue Extension events or by contacting Nennich at tnennich@purdue.edu.

Questions regarding nutrient management and manure application rules can be directed to the Office of Indiana State Chemist based at Purdue University at 765-494-1492.