By DOUG SCHMITZ
Iowa Correspondent

ATLANTIC, Iowa — A new rule imposed by the Iowa Department of Natural Resources (IDNR) and the Iowa Environmental Protection Commission (IEPC) that would mandate tight restrictions on how winter manure could be applied to frozen- or snow-covered ground surfaces has state farmers scrambling to adjust their fertilizer plans.

“Applying manure on frozen or snow-covered ground is risky business because the manure thaws on top of the ground and runs off before the ground thaws, and it can soak in,” said Dan Olson, environmental specialist in the IDNR’s Atlantic field office.

“Producers need to know that they may be setting themselves up for a problem, and (need to) carefully evaluate the risk that the manure could reach a stream or underground tile inlet before they apply.”

Signed into law on May 27 by Gov. Chet Culver, Senate File 432 prohibits the surface application of liquid manure on snow-covered ground from Dec. 21-April 1, and on frozen ground from Feb. 1-April 1, except in emergencies.

While the bill does not restrict winter application of dry, solid or bedded manure, it does specifically apply to liquid manure originating from confined animal feeding operations (CAFOs) where the IDNR would require producers to submit manure management plans.

“For the most part, the law will affect confinement producers with hog operations housing 1,250 or more finishers and dairy operations with 350 or more dairy cows,” said Gene Tinker, IDNR coordinator of animal feeding operations.

During the process of enforcing the bill, which went into effect July 1, the IDNR claimed there was an increased potential for runoff due to snowmelt or rainfall in winter and early spring because water wouldn’t be able to infiltrate soils that were frozen or snow-covered.
“Surface application of manure under these conditions can lead to lost nutrients, degraded water quality and possible penalties,” said Claire Hruby, a geologist with the IDNR’s animal feeding operation program. “The risk of runoff is higher for liquid manure. However, runoff from fields where solid manure is applied can also contain dissolved nitrogen and phosphorus.”

In turn, to reduce the potential impact of runoff on Iowa’s water resources, Hruby said the IDNR decided to draft rules that would prohibit surface application of manure on frozen or snow-covered ground under certain conditions.

“Surface application would be prohibited when the risk of runoff is highest, such as late winter just prior to snowmelt, on steeply sloping ground and in areas near tile intakes,” she added. “Current rules prohibit surface application of manure near streams, wells and other designated areas.”

Moreover, farms subject to the proposed rule may have to modify manure application practices or increase the amount of manure storage to comply with the rule, which would also require producers to develop maps showing areas where surface application would be restricted when the ground is frozen or snow-covered, the IDNR added.

Conversely, Karen Grimes of the IDNR Communications Bureau said the department didn’t recommend that Iowa farmers cut fertilizer applications drastically.

“What the IDNR did was model six ‘what-if’ scenarios to see if reducing human waste or cropland fertilizer usage in the Des Moines River’s watershed could reduce the amount of nitrate reaching the Des Moines Water Works to acceptable levels – approximately a one-third reduction,” she said.

“The result of the modeling showed that we face an immense challenge in meeting that goal. It clearly showed that no one action would reach a federally set, health-based goal for drinking water coming into Des Moines.”

In March, more than 700 members of the Iowa Cattlemen’s Assoc. (ICA) met with the IDNR to discuss the then-proposed measure, saying the bill would update an antiquated section of the Iowa Code which stated CAFOs only handled liquid manure.
Planning ahead for winter, the ICA and the Iowa Pork Producers Assoc. (IPPA) drafted their own legislation to address what they said were the IDNR’s heavy regulations.

“During winter months, cattle producers use considerable amounts of bedding materials such as cornstalks and straw, which have to be removed from pens and buildings, particularly following snow events,” said Kent Pruismann, a Rock Valley producer and ICA president.

“This dirty bedding needs to be applied to farmland and adds organic matter as well as nutrients that can be used by crops. The bill does restrict the application of liquid manure to frozen and snow-covered ground,” he added, “and proves that a choice does not have to be made between livestock production and environmental protection.”

Asked whether the IDNR should have the unlimited power to permanently enforce the new manure law, Jim Fawcett, Iowa State University field agronomist in Iowa City, said he thought it would be better to promote the use of appropriate amounts of nitrogen in a manner that reduces losses rather than make an across-the-board cut in rates.

“Hopefully, there will be new technology in the future that will help reduce nitrogen losses,” he said.

“Nitrogen losses not only are bad for the environment but are bad for the farmer’s wallet as well.”