Serving Minnesota and Northern Iowa.

Conservation leaders say soil health is in trouble

By Janet Kubat Willette
jkubat@agrinews.com

Date Modified: 06/25/2012 1:56 PM

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For years, farmers said when commodity prices rose they would invest in conservation.

Prices have risen to near historic levels and conservationists are waiting for their phones to start ringing.

Instead, conservation is declining as farmers seek to work every possible acre. Marginal cropland once enrolled in the Conservation Reserve Program is being put back into production without allowances for conservation.

In Steele County, 26,000 acres were enrolled in CRP from 1986 to 1996, said Dan Arndt, district manager of the county Soil and Water Conservation District. That was about 4 percent of the county's cropland.

That number had declined to 10,650 acres as of the end of April, said David Charles, county executive director of the Steele County Farm Service Agency. In the recent signup, 45 offers were made by willing landowners.

"There was more interest than what I thought there'd be," Charles said. USDA announced that 3.9 million acres were accepted on Friday.

A move toward more aggressive tillage has occurred, Arndt said, with less residue left to protect the soil.

"I have not seen the landscape look so black and so exposed as it does this spring," he said.

Farmers tell him they do the aggressive tillage because it increases yields from three to five bushels per acre. Add in rollers and it's a recipe for erosion, ponding and crusting.

Rolling crushes surface soil aggregates, said Extension educator Jodi DeJong-Hughes, who has done research on soybean rolling since 2008. It leads to less water infiltration, more sealing of the soil and more wind erosion. The erosion may be worst this year because soil got so cloddy last fall with the dry weather and required more tillage this spring to bring into planting condition.

More tillage also broke up the soil aggregates into individual particles of soil, which tend to be more mobile, and incorporated more residue, which acts as a blanket on the soil.

As a result of weather conditions and increased tillage, there is very little to protect the soil in the event of heavy rains or high winds. Wind erosion starts at 13 miles per hour wind speed, she said. The topsoil blowing into ditches is the best soil. It's the soil rich in organic matter, phosphorus and nitrogen.

"You want to keep (your soil) where your plants can use it," she said.

Rolling, though, does have benefits, DeJong-Hughes said. It pushes down rocks so combine heads can be set almost to the ground allowing all pods to be harvested. Root ball sickle damage is all but eliminated. It helps with operator fatigue because the operator doesn't have to be constantly vigilant for rocks.

There have also been some reported yield increases. In 2010, one out of seven fields showed a 1.7 bushel increase attributable to rolling.

Rolling may help manage residue for farmers who practice reduced tillage, spurring the breakdown of residue.

Arndt said there are farmers who are doing a good job of managing their soil resources, including those who installed 17 miles of buffer strips in Steele County last year, but he fears the actions of those who refuse to adopt conservation practices will result in more regulation.

"Our soil health, water quality and our wildlife is in trouble," Arndt and Noel Frank, district conservationist in Steele County, wrote in a commentary published in Agri News last week. "If our producers are concerned about this, we would like to help. Good conservation practices and management will pay for themselves."

"Conservation may take more management," adds Tom Coffman, district conservationist of the NRCS in Rice County. "Conservation practices in a field may lead to less efficiency in planting the field. Conservation takes commitment. You need to decide between protecting your soil and being insured against heavy spring rains or gambling every year that you're not going to get hit."

Coffman offers conservation ideas to consider:

• Consider breaking the field into more than one crop in conventional corn-soybean rotations using full-width tillage systems. Having alternating fields of corn and soybeans with different tillage systems will help slow runoff and erosion.

• Consider a third crop in your rotation.

• Consider no-till, strip till or ridge till. Can it be used on some fields? Can it be used half the time, say no tilling soybeans into corn stalks?

• Consider cover crops. Can a cover crop be flown on growing soybeans in August or September? Cover crops are good for soil health and provide nutrients for next year's crop.

• Consider if rolling a field is necessary or if rolling baskets are needed on your field cultivator. This equipment breaks soil clods into single grain particles that are more vulnerable to soil erosion, surface sealing and soil crusting.

"The USDA NRCS and local SWCDs have offices in every county," Coffman writes. "We are willing to walk your farm with you and discuss options. Give us a call."