When Steve Berger’s Wellman, Iowa, operation started no-tilling in the 1970s, they thought no-till was the gold standard.
But then they attended a few conferences and learned they were still losing organic matter in their corn-soybean rotation. No-till, alone, wasn’t enough.
“That’s quite a pill to take when you thought you were doing the best of the best and weren’t quite getting there,” Berger told the audience at the Iowa Cover Crops Conference last month.
So in the past 15 years, they’ve added cover crops, particularly cereal rye, to the operation and consider it to be one of the best management decisions they’ve made.
He knows the same can’t be said for all no-tillers, and has witnessed neighbors struggle with cover crops. But Berger thinks if you focus on the following four keys, you’ll find success with cover crops.
1. Corn Planter Setup
Berger says corn planters need to be set up correctly to plant through cover crops, and he recommends growers attend a planter clinic. He also thinks applying nitrogen (N) with the planter is very helpful to help get early seedlings off to a better start.
2. Manage for Insects
Berger says it’s a minor detail, but cover crops can attract insects and no-tillers need to manage them.
“I’m not saying you have to use insecticides — just know that insects can take a certain percentage of your crop and lead to failure, and then you won’t like cover crops,” he explains.
Probably the most important thing is N, Berger says.
“We need to learn to manage N differently in a no-till, cover-crop operation,” he says. “I’m not saying you put more on, but you just need to manage when and where and how we put it on.”
When soil microbes are busy breaking down no-till residue, they’re using N to break the carbon down, and the corn can suffer from an N deficiency. On his farm, Berger starts applying N — usually ammonium sulfate — in early fall to feed microbes and ensure N isn’t tied up when corn is planted the following spring.
“It’s our job to make sure that corn is never short of N when it’s needed,” Berger says.
“Finally, we’ve got to have patience,” Berger says. “It takes time. The aggregate stability of soil changes slowly. It took hundreds of thousands of years to form soil — we can’t change this over night.”