INDIANAPOLIS — Picking the right cover crop can be confusing
for first-time users, but there are questions farmers can ask to find the right
Purdue University agronomy professor Eileen Kladivko offered
her cover crop advice at the Corn Belt Seed Conference in Indianapolis. Kladivko
said the most important question to ask is: “What do you want the cover crop to
“No one cover crop will meet all possible purposes that a
person might have in the field,” she said. “We need to evaluate what you want it
Purposes for cover crops include nitrogen scavenging,
nitrogen production, erosion reduction, soil health improvement, soil moisture
conservation, nutrient recycling, weed control, pest protection and long-term
Once farmers choose the purpose they are trying to achieve,
they can better make management decisions.
“I have a couple suggestions for people who want to know
what to plant,” Kladivko said. “My personal favorite cover crop is an oats and
daikon radish mix for corn.
“As long as beans come out on the early side, they are
excellent nitrogen scavengers, and they both winter-kill. If you’re nervous
about green cover crops for corn, it is an excellent choice because they are
dead before planting.”
She said that cereal rye in a corn-before-soybean system is
a good choice. It can be planted late and still do well, and if the rye gets out
of hand and ties up nitrogen, it won’t affect soybeans.
Good cover crop mixes could include a legume, grass and a
brassica. The legumes provide diversified root systems, and the grasses provide
top growth. Brassicas are used for diversity and as a nitrogen scavenger.
“You also have to consider the current cropping system,
whether it is till or no-till, what time windows are available and what soils
and climates there are,” Kladivko said.
“Sometimes people get discouraged when they try cover crops
for the first or second time and don’t have that much growth. I think there can
be quite a bit of benefits from cover crops even with modest amounts of
The root systems are often more important than the number of
shoots, she said. While top growth is good for forage or weed control, root
systems help improve soils, erosion and water quality.
Kladivko recommended the Midwest Cover Crops Council
website, which includes a cover crop selector tool.
“There’s been a huge surge in interest, as well as adoption
of cover crops,” she said. “Whether you’re selling cover crops or not, corn or
soybean producers have become very interested in cover crops and are asking for
information on it. I think it’s a business opportunity to help service those
growers who have questions.”
As people get excited about cover crops, they should know
that cover crops are part of a system, Kladivko said.
Folks are going to need to adapt their entire system for
growing cover crops. They may need to change nutrient management or tweak the
tillage or no-tillage system.
“They need to do their homework if they are considering
cover crops,” Kladivko said.
“The rationale is to make better use of the resources we
have here in the Midwest that we’re not taking advantage of now. It’s basically
to have something living and growing during the time of the year where we
typically have nothing growing.”
Having a plant photosynthesizing, sequestering carbon,
aiding soil microorganisms, recycling nutrients and building soils can be
beneficial, even if it is not a cash crop.
For more information about the cover crop selector tool,