Fallow field

With flooding and rain, some fields will not be planted this year. Farmers have plans to fight weeds and protect the soil for the 2020 crop.

TAYLORVILLE, Ill. — Purple isn’t a good look when it comes to corn.

Jeff Fraley, a Jerseyville, Illinois, farmer saw purple corn after the Illinois River breached the Nutwood levee district in southwest Illinois in 1993, causing thousands of acres of prevent plant fields. The odd color in some fields came from lack of useable phosphorous for the corn plants.

He wants to avoid off-color corn and will be planting soybeans or cover crops when he can.

“Roots in the ground” is the recommendation of Emily Heaton, Iowa State University Extension agronomist.

“We recommend planting a cover crop as soon as possible — whatever you can get seeds for,” she said.

The soil is a living organism; the microbes need food and air. They can get food from the roots of the cover crops and air from the root channels, Heaton said.

Independent agronomist Karen Corrigan also recommends cover crops in fields that will not be planted this year. They not only help keep the soil productive, they also help control weeds.

“There was a very large seed bank of weeds in 2018,” she said.

For those new to cover crops, she suggests starting small and using a cover crop that winter kills. A mix with oats or radishes and millet might be a good choice. A seed dealer will help customize the mix, she said.

Golden Harvest agronomist Stephanie Porter said if the ground is fallow in 2019, fallow corn syndrome could become an issue when planting corn next year. It can cause corn to be stunted or purple, as farmers like Fraley observed after the 1993 floods.

“The extent of symptoms can depend on management and weather conditions,” said Porter, of Taylorville, Ill. “Some research indicates … you could have a reduced uptake of nutrients such as phosphorus in fields with low phosphorus levels, so don’t skimp on the phosphorus this fall.”

Even weeds could be better than nothing, Porter said.

“The sad part is that weeds on acres that were not planted could be better than leaving the ground fallow, because some weeds do provide VAM (vesicular arbuscular mycorrhizae),” she said.

On the flip side, she said, some cover crops are not hosts for VAM, so if you plant only brassica cover crops such as turnips and radishes, you could still have fallow corn syndrome the following year.

“In our area, we are trying to plant soybeans as long as possible,” said the central Illinois agronomist.

Soybeans are still Joe Zumwalt’s first choice for planting. He farms in the Hunt-Lima Drainage & Levee District in western Illinois, where many aren’t finished planting yet. He said he expects planting will continue through mid-July. Some will be uninsured soybeans, other will be cover crops.

Cover crops can certainly prove valuable in kick-starting soil biology that has been damaged by prolonged flooding, helping suppress weeds and prevent erosion in fields that would otherwise sit idle, said University of Missouri Extension agronomist Rob Myers.

They may also be a source of income if they are hayed or grazed, though some restrictions apply, he said. Cover crops are allowed on fields that have been classified as prevent plant. The USDA had restricted harvesting or grazing those crops until after Nov. 1, but on June 20 changed that date to Sept. 1.

Financial aid is available for planting some cover crops, Myers said, but it also has rules to be followed. A new option this year in Illinois is a pilot project led by the American Farmland Trust making farmers who grow cover crops eligible for a $5/acre discount on crop insurance.

For cover crops planted before the end of July, the best choice is warm-season crops such as sorghum-sudangrass, pearl millet, cowpeas, sunn hemp, sunflowers and buckwheat. After Aug. 1, he recommends switching to a cool-season mix that might include cereal rye, radish, hairy vetch and oats.


Web resources

University of Missouri Extension agronomists and economists have created a “one-stop shop” of online resources for grain farmers coping with flooding and persistent rains at https://bit.ly/2KtdAMa

The Midwest Cover Crop Council put together a cover crop selector tool at http://mccc.msu.edu.

And the Illinois Nutrient Research and Education Council has a guide for first-time cover crop users at https://bit.ly/2RoYpnP.