RENVILLE, Minn. — Saving your soil. Those three words appear to be the driving force behind the adoption of minimum tillage and cover crops. For most farmers, saving your soil is a no-brainer. Everyone talks a good game; however, putting it in action is another matter.
But not so for Dean Schroeder, a Renville County, Minnesota farmer. He’s been practicing strip till/no till for 15 years and now plants cover crops for the past five years. Why?
“I just didn’t like our soil loss when we were in conventional tillage,” commented Schroeder. “Strong winds we’d see soil whipping; after rains soil washing into the creeks … that bothered me and we said there’s got to be a better way.”
Schroeder admits his conscious got to him. There were also some potential cost savings because of fewer trips across the field. “So less fuel and lots less hours on the tractor.” He started with a chisel plow in corn stalks. “We haven’t moldboard plowed for about 40 years. In our corn/soybean rotation, we plant soybeans between last year’s corn rows without any tillage before planting. Been doing that for about 15 years.”
Now Schroeder is into strip tillage with a Nifty-Reaper strip till shank machine. Hitched behind, a Montag Air Cart with double tanks permits both phosphorus and potassium applications. This system also lets him variable rate each fertilizer separately. His fields are soil sampled in two-and-a-half-acre grids. Schroeder prefers a shank machine which requires a bit more horsepower, but it will work 6 inches into the soil profile versus a ‘coulter’ machine that works only 3 to 4 inches deep. He also indicated there are now several brands of strip till equipment in the market. The Nifty Reaper is made by Niffty Ag Inc. of Galesburg, Illinois. A Minnesota-made machine is the Soil Warrior, manufactured in Faribault.
So why is soil health now common conservation with farmers into minimum tillage?
For Schroeder, soil health really wasn’t an issue those first years of strip till. “But the last 6 to 7 years we’ve seeing the advantage of building soil health too. Our crops can handle stress conditions better — be that fungus diseases or weeds or even moisture, too much or too little. We’re now five years with cover crops. The more we do cover crops, the more I see that’s an important piece of the puzzle.”
The decision to utilize cover crops raises a number of question such as: What kind of cover crop? Multiple species or just a couple? When to seed your cover crops? Do they work in corn too? Can you harvest soybeans and then seed cover crop? Does aerial seeding into corn work?
“The first year we just used a single species, like a radish,” said Schroeder. “But we’ve since learned you want multiple species — both for what they do above ground to minimize wind and water erosion and also how much scavenging of nutrients deeper into the soil profile. It’s been a learning curve which keeps it interesting; but also shows more benefits to be gained. This mixture in this field has 12 different species. This provides even more varieties of root structure … some will gather up nitrogen; some will gather phosphorous for next year’s crop.
“Yes, it’s a never-ending learning process which is part of the fun and rewards. Every year I go to the national no-till conference which involves about a thousand or more no-tillers from across America. Networking with different farmers is always a good source of information. I’m not inventing the wheel. I like to copy from other farmers who are already making it work.”
Instrumental in Schroeder’s learning curve has been Holly Hatlewick, who is the district administrator for the Renville County Soil and Water Conservation District. “Her knowledge and how she teaches the farming community is tremendous.”
A good example of Hatlewick’s work is the Reduced Tillage and Cover Crop Field Day which took place on Sept. 14. Attended by 64 farmers, farm lenders, conservation technicians and media reps, the event included an update by David Mettler on cover crop test plots by the Southern Minnesota Sugar Beet Co-op. Before loading buses for a tour, Hatlewick shared this soil health teaser: ”The idea is to mimic Mother Nature,” she said. And another teaser: “a teaspoon of soil contains more living organisms than the world’s population.”
Renville County is rich with innovative and diversified farmers. Usually number-one in the state in corn production, the county is also among the top four or five in soybean production. Renville County farmers also grow sweet corn, field peas and edible beans. All of this production is spread across nearly 600,000 acres of cropland.
The Sept. 14 field day included stops at six farms which incorporate a variety of cover crops and cropping systems. Schroeder’s farm was the last stop. A handout received by tour participants read, “Fall 2017 no-till drilled winter wheat, followed by a broadcast frost seeding of Mammoth red clover. Harvested wheat on July 26, 2018, sprayed Gramoxone, then no-till drilled cover crop on July 28, 2018. Prior to 2017, the field has been continuous strip-till/no-till for 15 years. Field will be no-till corn in 2019. His cover crop mix: 3 lbs. each of sunflowers, buckwheat, cow peas and pea TS750; 4 lbs. Pieper Sudan grass; 7 lbs. kayle; 7 lbs. purple top prune; 1 lb. berseem” plus a few more listed on the handout.
Back at Schroeder’s farm, I asked Hatlewick if Schroeder was a good student? She smiled, “Dean is awesome to work with because he wants to try new things. Also, he’s willing to share with me what he’s got going on; plus he seems to thrive on doing innovative things.
“When I got to Renville County in November, 2014, I quickly learned he was already knowledgeable, so it’s been both a good teaching and a good learning experience for me. Sharing what we each know is special when your mission is to upgrade conservation and soil health.”
But why 12 different species of cover crop? Hatlewick responded, “I think he’s right on the money! With the diverse mix, you have even more things working for you. You’ve got species that are scavenging nitrogen. You’ve got a couple legumes building nitrogen. You’ve got broad leaves harvesting energy from the sun. You’ve got grasses that will be tall and narrow to protect your soils from wind erosion. So mixes are really important. We always try to get growers to do at least a three to four-species mix of cover crops. But I think 12 are awesome because you’ve got your soil working that much harder.”
A big help to Schroeder’s operation is the guy who sells cover crop seed. “He gives me recommendations on what he thinks would work,” Schroeder said. “He also suggests the pounds per acre of total seed and the pounds for each of the 12 species. Then we tweak it from there.”
As Schroeder inspects the abundant cover crop in his field, he likes what he sees. “This is about what I expected it could be,” he stated. “You never know the first time you plant such a mixture. Hopefully the turkey manure gets spread next week.”
Schroeder seeds 32,000 plants per acre on corn in 30-inch rows. He thinks today’s hybrids have enough flex so you can do with a lesser population and still achieve strong yields.
Schroeder admitted it is difficult to determine how much better his yields are with his techniques, but is confident of an additional 10-15 bushels per acre of corn.
Added Hatlewick, “With the good cover crop mix and this reduced tillage, you’ve rebuilt the soil structure considerably. You’ve got the sponge activity in your soils, so moisture absorption is that much better.” However, Schroeder noted, a 5-inch downpour did produce some drowned-out spots.
Hatlewick explained when you have good aggregate stability in your soil with irregularity and lots of open spore spaces, it actually acts like a sponge and can handle these bigger rainfalls. “It basically expands like your kitchen sponge and the plants draw up the moisture as needed. Where you don’t have that structure is where you end up with compacted, almost concrete conditions, because all those soil particles pack together.”
Hatlewick also reminded that when a raindrop hits the earth at 20 miles per hour, it can move soil particles up to 5 feet horizontally and 5 feet vertically. “All this movement is taking soil nutrients along too.”
Hatlewick added incorporating cover crops into a farming operation is a trial-and-error process. “You’ve got to make a plan,” she said, “then be willing to throw that plan out the window and come up with Plan B. Sometimes adapting on the fly and making decisions on the go is a good bail-out procedure. And it’s important to think also if this decision today goes backward next year, am I prepared to adjust. In a nut shell, it’s long-term planning rather than short-term planning.”
Schroeder used 28 percent nitrogen applied when corn is anywhere from 6 inches to maybe 2 feet in height. A Val-Mar air seeder is part of this N bar so he can “air blow” his cover crop at the same time — thus saving another trip. Cover crops in standing corn means fewer species that will tolerate the shading of the corn. If seeding cover crops into standing corn, think in terms of hybrids that aren’t so tall. Also, upright leaves that droop will shade much of the soil beneath them.
Summed up Hatlewick, “We just love to talk about how much ‘life’ is now in Dean’s soils. With this mixture he has really helped manage the livestock beneath the surface of his fields. Root activity of these cover crops is often 27 inches and deeper. When you crumble his soil, you almost sense it’s alive. it’s moving with living organisms, microbes and fungi and bacteria. I call that your ‘beneficial livestock’ beneath the soil surface. In Dean’s soils, you can see the streaks and lines where the earthworms are carrying his top soil down further into the profile. He’s actually building top soil at a very rapid rate. USDA says it takes 500 to 1,000 years to grow an inch of top soil. I’m certain Dean has grown more than an inch of top soil in the last 15 years since he got into reduced tillage and cover crops too.”
Said Schroeder, “Our goal is to leave the soil better than we found it.”