Another showdown looms over Iowa’s regulations governing farmers’ ability to spread manure on frozen or snow-covered fields.

Livestock interests are pushing legislation that would effectively lift the winter ban on applying manure, said Wayne Gieselman, the state’s environmental protection chief.

State environmental regulators vow to fight to retain the ban on spreading manure in the winter because they say the practice can lead to dangerous ammonia levels in streams.

Eldon McAfee, a lawyer for livestock interests, contends the new legislation is needed. He said a proposed rule drafted by Iowa’s Department of Natural Resources would force some farmers to add expensive manure storage without much warning.

House File 2324 and Senate File 2229 would exempt those farms from requirements that they install more manure storage to comply with last year’s law. That would allow the controversial manure applications.

The current law generally bans application of manure between Dec. 21 and April 1 each year.