Perennial Cover Crops and Wide-Row Corn

April 22, 2022

85% of the southern MN landscape is corn or soybean mono-crops. There is literally nothing else growing on this land and that’s a big problem! Here’s why:

Soil is a living system. Each plant species produces unique root exudates, sugary substances that feed life in the soil. When the landscape was native prairie and savanna there were hundreds of species on every acre, cool season, warm season, grasses, legumes, forbes, perennial, biennial, all of these and more! The corn and soy that now dominate the landscape are warm season annual plants and they only produce significant amounts of root exudate for a few short months of the year. The microbial communities and all life that rises from this foundation is literally starving to death! 

Contrast this to the natural ecological systems. Here there’s a blend of warm season and cool season so life is always happening! Surprisingly, even when the soil is nearly frozen! And let’s not forget the animals. There were once literally millions of bison and a full entourage of birds, mammals, and more intricately connected to the land. Trampling, manure distribution, and the gentle tugging on grasses are just a sampling of the beautifully orchestrated functions that maintained a thriving and abundant landscape.

Today, the majority of the animals are domesticated livestock and spend their entire lives in buildings, disconnected from the landscape. Corn and soy are fed to brought to them as feed and the severely depleted soil food web no longer functions. Our lakes and rivers are filling with sediment because the biology that holds the soil together, in aggregates, is greatly diminished. 

We can do much better and our on-farm research will help us inform ourselves and others on how we might do so.

Growing a corn crop, normal for our region, but doing so in a way that fully integrates greater biodiversity is what we will examine. The rows of corn will be spaced apart at double the normal distance to allow more sunlight to reach the lower levels. Since the corn plant is a life form that can readily adapt to different conditions it will collect sunlight through lower leaves (that would normally be in the shade) and respond by producing bigger or sometimes multiple ears. If the right genetic variety of corn is chosen and using careful management the overall yield of grain can even match the normal row arrangement.

The major benefit of more sunlight (energy) collected between the rows is allowing additional plants to utilize that energy. Remember the root exudate thing I mentioned? These plants not only product forage, which I’ll get to shortly, but are also feeding microorganism and providing habitat for a diversity of life including beneficial insects and pollinators.

Supporting the soil food web creates stable soil aggregates. As a result, rain that falls leaves as runoff rather than soaking in, infiltrating soil pore space, and drawing in life-giving oxygen as it moves through the soil profile. And, as a benefit to farmers, plant nutrients are cycled and made available, reducing the need for fertilizer inputs. As a side note, fertilizer prices are currently at record highs!

There’s a long list of other benefits that I won’t detail right now but I hope you’re beginning to see that when nature’s patterns are used as a guide to follow and learn from good things tend to happen!

The perennial cover crops we’ll attempt to grow will provide another resource we intend to explore. To bring back the animal component to an agricultural system working more like a healthy ecological system, we’ll be adding turkeys to the field!

The turkeys will be introduced once the corn is big enough to not be damaged and we will carefully manage them by moving them along to another area before their impact becomes a detriment instead of a benefit. We expect the turkeys to scratch around as the forage about eating the cover crop, insects, and perhaps “weeds” that spring up. They’ll certainly take advantage of the shade and protection offered by the corn and their manure provide the kind of nourishment that helps plants to thrive!

The title of the study:

Evaluating Soil Health and Farm profitability with Perennials and Poultry in Corn Production Systems

Look for more blog posts about this exciting project as plans are put into action! And, remember to reserve your turkey for Thanksgiving!

Scott Haase
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