Making the Best Ground Better

After 47 years in the fields of Central Iowa, farmer Kevin Holl is still finding ways to improve fields that already have some of the best corn-growing soil in the world. Here’s how he does it.

By Jamie Cole | Photos By Jamie Cole

The wind turbines on and near Kevin Holl’s Conrad, Iowa, farm are spinning today. It’s an ideal day for power generation, but not great for farming. There is a dust devil or two on the roads between Holl’s fields, but the short, greening cereal rye among the corn stubble is holding the soil fast.

Holl is quick to point out that much of the soil in Central Iowa is Muscatine, “which is the 95 to 100% corn suitability rating,” he says. The lowest CSR in any of his fields is 80%, he adds. Good thing for Holl; part of his ideal corn-growing acreage is in commercial corn, but part is in seed corn and seed soybeans for Corteva, an important and demanding crop that will wind up in commercial bags next season.

When asked if any of his fields are in Grundy County, famous for corn production, he reminds us his farm is one county over, but the question sets him up for that rarest of things: a conservation joke.

“On a day like today,” he laughs, “we get some of their soil blowing over here anyway.”

A little laugh at the weather shouldn’t imply, though, that soil conservation is anything less than a serious matter. To Holl, it’s been a years-long project inspired by an experienced farmer’s wisdom and observance of trends, an innovator’s sense of the leading edge, and a steward’s sense of of responsibility.

It does help that, farming-wise, Holl has seen it all. After growing up on his family land, he farmed his first acreage in 1975, learning to manage fields and finances. His part of the farm managed to survive the farm crisis in the 1980s while neighbors and even family members didn’t fare as well.

He remembers a drought that affected 17 Iowa counties in 1977, and rains in 1993 that stole yields to the tune of “50 to 60 bushels an acre,” he says.

But he also says those memorable weather events seemed like the outliers, until recently. “It’s just been more extreme events over the years. And I don’t see it letting up,” he says. Holl and his fields were in the path of the infamous August 2020 derecho. “We’ve had corn go down before,” says Holl, “but nothing like that.”

For Holl, weather trends first spurred a change to conservation tillage, an important step in improving corn ground that already had the best soil. “We have mostly ‘C’ slope,” says Holl, which describes the grade of hilly land that is classified as “highly erodible.” His conservation humor aside, Holl has seen enough of his soil literally blowing—or washing—away. “The erosion, and these heavy rains we’ve been getting for the last decade, and just seeing that soil down a ditch… it bothered. And I needed to save that soil.” Another bother was wheel tracks from equipment in his fields that were symptomatic of compaction that had to be abated.

So another change in practice came about from a simple field demo. “I was in a guy’s field; he had been using cover crops,” says Holl. “Nobody really knew about them at the time. We took a spade out there, and I tried it; you hardly had to push down on that spade. And it was a rolling piece of ground, and no erosion whatsoever,” he says.

Holl could literally see the benefit, and envisioned the practice on his own simliar land. Today, he’s mostly drilling in cereal rye—“Seed-to-soil contact, just like with corn and soybeans, is really important in getting something to grow,” he says—at a rate of about a bag per acre, depending on the time of year he gets it down. “Maybe a little more per acre if it’s later in the year,” he says. Cereal rye costs about $15 a bag on average, and then there’s the cost and time to plant. NRCS offers some cost-share based on location and specific practices, and some producers might find that cost-share will pay for all or most of the cost.


Putting the pencil to return per acre can be tough, but Holl says the benefits stack up. “It’s not a one-year deal,” he says. The National Cover Crop Survey, released in 2020, gathered responses from 1,172 farmers from all over the U.S. While some farmers have been slow to try cover crops like rye for worry of yield drag—rye was thought to tie up N in spring making it less available to the corn crop—yield gain was consistent in the survey, in corn and beans. Almost half of corn growers reported lower fertilizer costs.

DOWNLOAD the 2019-20 cover crop survey for more results:

Keeping nutrients where they’re supposed to be is crucial for any crop, but particularly for seed corn. “The seed company was worried about stratification of the fertilizers,” says Holl. “Cover crops seem to have taken care of that,” he says, because the practice has improved absorption. By the same token, he’s seeing less standing water in the fields, meaning he can get in to work them faster after a rain. Holl could actually see this benefit; short-term water infiltration tests backed it up with data. “That alone should make folks want to jump in on this,” he says.

Longer-term field tests on infiltration, along with evaporation, amount of organic matter, weed and pest pressure, runoff, and other environmental factors believed to be improved by cover crop use will eventually help develop software that farmers and NRCS personnel can use to guide decisions and better determine ROI.

But Holl isn’t waiting around. He has become such a believer that he even employs his conservation practices on leased land. “I treat it like my own,” he says. And he’ll use his experience as a practitioner and his work with his county’s soil commission—which he’s done for 15 years now—to influence others. It might be a tough sell, for the time being. Unlike conservation tillage, cover crops add steps to the growing season rather than eliminating them, along with more time and (maybe) money, two things most farmers agree are in too short supply.

But on a windy day in Iowa, Holl can face a stiff, soil-free breeze and smile when he says, “My advice? It won’t happen overnight. But keep at it.” And keep your dirt and nutrients at home, where they belong.

WATCH BELOW: Kevin Holl is a long-time Fendt fan. Check out his 1955 F12 Fendt Diesel.