Cover Crop Know-How

Five Troubleshooting Tips for Cover Crops This Fall

Emily Unglesbee
By  Emily Unglesbee , DTN Staff Reporter
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This summer and fall, Illinois farmer Chase Brown has been busy selling and spreading cover crop seed, which has been growing in popularity in his region. (DTN photo by Pamela Smith)

ROCKVILLE, Md. (DTN) -- When Chase Brown started selling cover crop seed eight years ago, he saw it as a small side-gig to supplement his farming operation near Decatur, Illinois.

Now, like many farmers, he's happy to discover it is a growing industry worth investing in.

"I started selling cover crops in 2012 for extra vacation and beer money," he admitted. "But it has blown into a substantial business. It has gone from guys throwing some cover seed out each year, mostly for government programs, to really thinking about it and planning. They've seen the benefits and attitudes are changing."

This year, cover crop seed demand for Brown Seed Sales was off the charts. "This year, a switch just flipped," he said. A lot of factors might be at play: The stagnant spring and early summer commodity prices pushed growers to trim chemical costs, an August derecho flattened some Corn Belt fields, and in the midst of a growing herbicide-resistant weed epidemic, dicamba herbicides were abruptly pulled off the market in June.

But the result is the same, Brown said. A lot of people are seeding cover crops for the first time -- and sometimes running headlong into a steep learning curve.

With help from cover-crop veterans, seed sellers and scientists, we've rounded up the top five troubleshooting tips to keep in mind for first-timers -- or even second- and third-timers.


One of the most common mistakes farmers make when approaching cover crops is thinking of it as a one-time, single-season decision, Brown noted. Even if you choose a cover crop that dies over the winter, springtime will bring residue and nutrient management considerations.

"You have to wrap your head around managing it throughout the whole year," he explained.

On the planting side, cover crops sown earlier in the fall will give you more cover -- and more benefits -- in the fall season, said Joel Gruver, a soil scientist and agronomist at Western Illinois University. But certain winter grain covers, such as cereal rye, can get established as late as Thanksgiving, and still produce spring growth and its ensuing benefits, such as weed suppression and erosion control.

So don't be discouraged if fall harvest plans push your seeding window back -- but do be prepared, Gruver said.

"The later you go into the fall, the less growth you will have in the fall, so a higher seeding rate can compensate for that to some extent," he said.

Time is usually a fall cover cropper's greatest challenge, Gruver said. "Try to stack activities," he advised. "Spread seed while you're spreading fertilizer or incorporate seed while you're chopping residues. Look at normal field operations and find ways to kill multiple birds with one stone."

Never plant a cover crop without a plan for how you will terminate it, Brown added.

Some cover crops will die over the winter, but winter small grains, such as cereal rye, survive and grow in the spring. Termination options range from herbicide applications to roller-crimpers, and the timing of that termination can determine how much weed control or nutrient supplementation you get back from your investment. And of course, the weather may be your ultimate decision-maker.

"You need a plan A, a plan B, plan C and maybe even a plan D," Brown said. "Every year is different."

See more on spring termination considerations here:….


"Start small," Brown said. "Don't try to do your whole farm the first year."

Look for trouble acres that most need the benefits cover crops supply, Gruver added. "Target fields where you have erosion problems, weed suppression needs or nutrient scavenging concerns."

Farmers have dozens of species and mixes to consider. Keep the following year in mind; whatever you grow in the fall and spring has to work with your spring row crop, Brown cautioned.

On a corn-soybean operation, seeding cereal rye in the fall after corn and before soybeans is a tried-and-true cover crop plan, Gruver said. But it can't be reversed easily -- seeding cereal rye before corn requires very careful termination management to avoid tying up nitrogen in the soil when corn needs it in the spring.

Fortunately for those getting started this year, the Midwest Cover Crop Council has recently updated a tool aimed at helping farmers untangle their options and find what covers are best for their operation and needs. Their "Cover Crop Decision Tool" considers location, agronomic needs, current and future cash crop, field drainage and more. Then it supplies a list of potential cover crops, ranked by type and best fit, with details on each cover's management and biology.

See it here:….


Cover crop seed sources vary widely, from certified seed from established companies to a neighbor's silo full of leftover wheat.

Buyer beware, Brown cautioned.

"You can get on Facebook Marketplace or Craigslist and find some pretty darn cheap rye," he said. "But the problem is that germination is a big deal for rye. As humid as it is in Illinois, if they didn't know how to cool it down and store it, you could have some pretty poor germ." Rodent and insect damage can also take a toll on seed quality.

Overall, keep in mind that there are different processes for harvesting crops for grain versus seed, which is handled and stored more carefully to protect viability and germination of the seed, Gruver agreed.

"You don't always have to get expensive, certified seed, but you should try to get seed from someone who handled it with the intent of it being used for seed," he said.

Seed companies should list the results of the most recent germination tests on the seed tag, said Patrick Reed, vice president of sales for LaCrosse Seed in Wisconsin. But if you don't have that -- or you want to verify what you do have -- consider running your own germination tests, Gruver said.

"Count out seeds and put them in a moist paper towel and it will only take a couple days to see how many germinate," he said.


Herbicide carryover can be a major problem for cover croppers, especially those who didn't plan on planting covers but were forced into it by prevented planting or crop losses.

In dry growing years, without the rain needed to activate and incorporate herbicides on the soil's surface, lingering chemicals can hurt the emergence of legumes and brassicas such as clovers or radishes, Gruver said.

"It's becoming an even bigger concern as we fight more herbicide-resistant weeds," Brown noted. "You can't layer in two or three different residuals on soybeans in a dry growing year and then expect some of these more sensitive cover crops to do all right a month later."

Cereal grains, especially cereal rye, tend to be more resilient, and of course, seeding them later in the fall can also protect them from exposure to leftover herbicide residues.

Many universities have done research on which corn and soybean herbicides affect which cover crops the most.

See a roundup of University of Missouri research here:….

See a guide from the University of Minnesota here:….


In general, the earlier you decide on a cover crop strategy and order seed, the better, Gruver noted.

Fortunately, for latecomers this fall, cover crop seed supplies look good for now, LaCrosse's Reed said.

The early summer pinch on radish seed, driven by high usage from prevented planting acres last year, has mostly resolved itself, thanks to harvest underway in the Pacific Northwest. "We also saw a lot of carryover seed coming into the summer and fall, because last year, we had such a delayed harvest and a lot of people weren't able to plant covers they had planned on," Reed said.

But keep in mind that seed companies cannot always turn around an order on tight notice, especially this year, he added. The pandemic's strain on the nation's transportation industry hasn't left agriculture untouched.

"Freight across agriculture is higher right now, and it's harder to find trucks," Reed explained. "So give your retailers some time. Even just giving them a few days or a week before planting helps the whole channel out, and growers can get better quality, options and pricing that way."

To add to the year's challenges, a lot of cover crop seed is grown in the Pacific Northwest, where wildfires have been causing chaos and destruction for the past two weeks.

"So not only is it more difficult for these suppliers to ship to the Midwest this year, but now the seed and storage facilities are in danger in some cases, too," Reed said.

See more on cover crop production from the Midwest Cover Crop Council here:….

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Emily Unglesbee