Saving the Soil

Article from Newton Daily News | By Mike Mendenhall

PRAIRIE CITY -- In the warehouse at Heartland Co-op in Prairie City, Seed Specialist Steve Uhe opened a large vine sack on a wooden pallet. He cupped his hands and scooped cereal rye seed out of the bag.

“There are more and more people using it,” he said. “As in any farming endeavor there are the early adapters and the people that sit back. But I know every farmer is talking about it.”

Uhe said Heartland Coop customers and Jasper County farmers in general seem to be part of the early adopters in Iowa. Cover crop has been used in the eastern part of the U.S. for over a decade. It has been shown to stop soil erosion and act as a filter, catching farm runoff before it silts into nearby waterways.

Cover crops like cereal rye began to trend in Iowa four to five years ago when water quality and soil pH levels began to pose a problem for farmers and city water treatment plants alike.

“We were having real heavy rains and people were having erosion issues,” Uhe said. “So people were investigating ways to really slow that down."

On top of erosion control, Uhe said farmers have seen additional benefits to cover crops in the area of weed control – suppressing winter annuals. Cover crops have also helped soil structure in Iowa farm fields, building organic matter and trapping nutrients into the soil over the winter months when fields would normally see a loss of nutrient content.

Uhe said cover crops sequester nitrogen — a key nutrient in corn production— hold the fertilizer and release it into the soil as the cover crop breaks down in the spring. As cash crop is harvested, there is nothing to retain that moisture and nutrient causing farm runoff and degrading local water quality. The cover crop holds that nutrient, keeping it for the next season’s cash crop.

“The nice thing is the corn comes along a few months later and the nitrogen is there for it to use,” he said.

Some research has shown that cover crops can also help breakup the dry, thick layer of soil below the soil called the hardpan. This dry layer of subsurface soil can be caused by increased acidity in the earth. Uhe said if a farmer plants a rye, turnip or radish for three to five years, the added cover crop can reduce that pH level by allowing water down into the hardpan and increase cash crop yield.

At a conference in Des Moines, Uhe has spoken with farmers from Illinois and Indiana who have planted cover crops for 10-12 years who claim to experienced 20-25 bushel per acre increases in cash crop yield as a direct result.

Gordon Wassenaar is a corn and soybean farmer south of Prairie City. This fall will be his fourth season using cover crops. Last year he planted 1,200 acres of cereal rye following the fall harvest. He said he did not invest in the crops increased yield, but as a long-term investment to stop soil erosion on his land.