Cover Crop Concerns

11:33AM Jul 15, 2019
Farm Journal Pulse: Are you planting cover crops this year?
Farm Journal Pulse: Are you planting cover crops this year?
( Lindsey Benne )

Whether you’re intent on using cover crops for weed suppression on prevented plant acres or want more traditional benefits (to prevent erosion, improve water-holding capacity and reduce fertilizer use), your No. 1 challenge this season is likely the same: seed availability.

“Our seed industry is facing unprecedented challenges due to short hay stocks, winter kill and now prevented plant acres,” says Scott Wohltman, cover crop lead for La Crosse Seed.

Tight Supply

Many of the commonly used small grain cover crops, such as rye, wheat, barley and oats, are nearly sold out. The same is true for many annual forage grasses, such as forage ryegrasses, and warm-season grasses, such as forage sorghums and sorghum sudangrass, Wohltman notes.

“Outside of waiting for better availability or seeding a traditional non-grain cover crop, like clovers and brassicas, farmers across the country are currently extremely limited in their choices,” he adds.

What Constitutes a Cover

USDA’s Risk Management Agency (RMA) has a “broad definition” for cover crops used for crop insurance purposes, notes Richard Flournoy, deputy administrator of product management for RMA.

“It’s generally many things, any crop that can be planted for erosion control, soil improvement or any other type of conservation practice,” he told “AgriTalk” host Chip Flory.

Additionally, Flournoy says an “ag expert” can deem a crop eligible by determining the prospective crop meets all the cover crop definitions.  

That means even soybeans or corn can be considered a cover crop, but bear in mind you can’t harvest the crops for grain.

“Corn is deep-rooted and by the end of the growing season can produce significant residue even when planted in July,” says Joe Lauer, Extension agronomist at the University of Wisconsin-Madison. “The first thing you must do is talk to your crop insurance agent and make no decisions without their input.”

Set Your Goals

As you evaluate growing a cover crop, identify your priorities first, advises Anna Morrow, program manager for the Midwest Cover Crops Council. A big one for farmers this year is weed suppression on prevented plant acres.

“If you have heavy pressure from difficult weeds, such as waterhemp, Palmer amaranth and marestail, it may benefit you to plant a grass cover crop, so you can control those weeds with a broadleaf herbicide,” she says.

For farmers willing to wait until a new round of cover crop seed is available, the options and supply will be a little bit better. “New crop oats will be ready by late July, but new-crop rye will not be ready until mid-August at the earliest,” Wohltman says.

If summer annual seed availability is low, Morrow adds you might consider controlling weeds until August with herbicides and then plant a cool season species or mix.

Even with new cover-crop seed coming on the market, Wohltman says to expect supplies to be tight.

“Talk with your trusted adviser as soon as possible — the earlier you turn in your order, the earlier you’re going to get your name in the queue,” he says.

As for price, Wohltman says you can expect to pay between $18 and $25 per acre for seed, depending on which cover crop you choose.


3 Management Tips for Success

When selecting a cover crop for this season:

Evaluate your herbicide program. Consider the potential impact of any herbicide you applied this past spring in anticipation of a cash crop. Refer to herbicide labels for details on potential carryover. Brassica and legume cover crops can be especially sensitive to residual herbicides.

Plant clean seed. Make sure your seed is clean so you don’t introduce any new weed species. Check the seed tag for the germination rate, which can influence planting populations. “If you have good, clean seed with a lower germination rate, there’s nothing necessarily wrong with the seed, but you’ll want to plant it at a higher rate,” says Anna Morrow, program manager for the Midwest Cover Crops Council. “This is especially true for bin-run seed. At the very least, do your own germ tests, if there‘s not time to send off a sample.”

Remove top growth. If you plant a cover now, you could get a considerable amount of tillering prior to winter, and you might want to remove some of the top growth before cold weather sets in. “Think about how much growth you’re comfortable with prior to winter because if that crop gets away from you, it could be a bigger issue to manage next spring,” says Scott Wohltman, cover crop lead for La Crosse Seed.


For details on when corn can be used as a cover crop as well as other information on growing cover crops, visit www.AgWeb.com/cover-crop-concerns