Why Should I Plant Cover Crops?

Do you have a favorite tool that goes everywhere with you? Maybe you keep it in your pocket, or in your pickup, or perhaps it has a place of honor in your kitchen where it's readily accessible.

Our favorite tools generally have more than one use. The Swiss Army knife is one such tool that many people keep close by at all times. The usefulness of this tool comes in handy in a variety of situations, and to leave the house without it would make many people feel unprepared.

Similar to the Swiss Army knife, cover crops have many uses. Going without cover crops leaves farmers who use them feeling exposed and less prepared for all the curveballs farming or ranching can throw at them. Once you get used to having a specific tool in your pocket, you don't ever want to go without it. In the same way, once you get used to the benefits of using cover crops, you likely won't be able to picture yourself going back.

But why try cover crops in the first place? Maybe you're not seeing any erosion on your fields. Maybe you don't have problems dealing with herbicide-resistant weeds. Perhaps you already have wonderfully dark and crumbly soil that readily filters moisture after a heavy rain, but retains that water holding capacity so your crops are drought resistant. There may be one or two of you out there who have this all figured out, but for the rest of us, we need a tool to help us in these situations.

Cover crops are a beautiful tool to have in our toolbox because of their versatility and ability to address multiple problems at the same time. Recall the six principles of soil health: know your context, keep the soil covered, maximize diversity, minimize disturbance, keep a living root in the soil, and integrate livestock. When we consider each of these principles, cover crops can help us implement each one of them in accordance with our unique context. Cover crops keep the soil covered and a living root in the ground. With over 100 different cover crop species, the possibilities to add diversity are endless. If you're trying to minimize disturbance, either chemical or physical, cover crops offer solutions for both compaction breaking and weed suppression. In addition, livestock can utilize cover crops for forage all throughout the year in various forms. If you're interested in implementing the six principles of soil health, cover crops are an excellent place to start.

The Many Benefits of Cover Crops

Reducing Erosion

Reducing erosion might be the number one reason why people start using cover crops in the first place. Nobody wants to see precious topsoil blow or wash away every year. Farmers inherently know their topsoil is their most valuable asset. Without it, we aren't able to farm successfully.

Living roots and full soil coverage helps to physically protect soil from wind and water. Also, cover crops house beneficial soil microbes which create a glue-like substance called glomalin that helps hold soil together, further preventing erosion. Starting with a cover crop to help reduce erosion opens the door of opportunity to witness even more of the benefits of cover crops.

Improving Infiltration

When your neighbor asks, "How much rain did you get?" can you honestly say, "All of it"? Most soils in the United States today do not have the same water holding capacity they did 200 years ago. All too often, a big rain storm drops a plethora of water on an area, and only a few weeks later the plants are drying up and the soil looks like a parched desert. This isn't how healthy soil should function. A lack of organic matter, soil structure, and soil microbes contributes to the loss of this function. Adding a cover crop to your rotation is a catalyst for increased microbial activity, improved soil structure, and increasing organic matter. Many farmers across the US experience a decrease in soil erosion when they start using no-till practices. After a while of just no-till, however, the ground can become compacted and impenetrable. Cover crops help break compaction and create more pore space in the soil profile, allowing water and air to infiltrate and feed the system.

Suppressing Weeds

There's an old saying that goes, "If you keep doing what you're doing, you'll keep getting what you're getting." This statement is especially true when it comes to dealing with herbicide-resistant weeds. If we continue to try to fight weed pressure with higher quantities or more lethal forms of herbicide, we're going to keep making the problem worse. As an alternative, cover crops provide a solution to combat these weeds. On Providence Farms, Green Cover co-founder Brian Berns uses cereal rye to almost eliminate marestail as a problem weed. Indiana regenerative farmer Rick Clark shoots for 6,000-8,000 pounds per acre of biomass to help with weed suppression during the growing season. This thick mat of cover crop creates a mulch that the weeds cannot grow through.

Nutrient Cycling

When people think of nutrient cycling with cover crops, nitrogen fixation usually comes to mind first. Normally, we think of nitrogen fixation occurring on legume plants with specific rhizobia bacteria, but many other microorganisms can also fix nitrogen. A healthy system contains a balance of thousands of microbial species to cycle the nutrients it needs. Impressively, a single crop of hairy vetch can fix up to 200 pounds per acre in the right conditions. Keep in mind, however, that too much nitrogen can cause problems with soil health. A cover crop with a good balance of grasses, legumes, brassicas, and broadleaves can fix 60-120 pounds per acre of nitrogen.

Cover crops also help cycle other essential nutrients, including boron, zinc, copper, and manganese. The more biologically active your soil is, the more nutrients become available to your plants, so ramping up biological systems with cover crops helps you grow healthier crops with fewer synthetic inputs.

Grazing Opportunity

Cover crops make high-quality forage for all classes of livestock and can be strategically planted to provide forage when you need it most. Grazing allows livestock to utilize cover crop biomass and return nutrients back to the system, building soil quickly and encouraging biological activity. Integrating livestock with cover crops demonstrates the wisdom of working with natural systems—animals deposit nutrients, stimulate plant growth through grazing, and inoculate the soil with beneficial microbes.

Mixes vs. Monos

While a cover crop can be planted as a diverse mix or as a single species monoculture, we see the most benefit coming from strategically diverse mixes. When you match your cover crop species to your goals, a mix of 5-8 species from 5-8 different plant families really starts to unlock the potential of the soil and, by extension, the potential in your crops. Considering ways to add a diverse cover like this to your rotation will kickstart your progress towards soil health.

Matching Species to Your Goals

Here are some common goals and recommended cover crop species to get you started:

• Nitrogen fixation: Hairy vetch, clovers, field peas
• Compaction breaking: Daikon radish, tillage radish, forage radish
• Weed suppression: Cereal rye, wheat, barley
• Biomass production: Sorghum-sudangrass, pearl millet, cereal rye
• Forage quality: Brassicas (turnips, rape), clovers, small grains

Just Start!

The dominant corn-bean rotation is not the most ideal situation for using cover crops due to late harvest windows, but it can still be done! Get started with a rye-based cover crop mix planted after corn, ideally as early as possible. This mix can sequester and store any carry over nitrogen ahead of the next soybean crop. After your soybeans, a mix of winter barley, hairy vetch and winter clover can work well prior to the next corn crop.

If you really want to ramp up your soil health and reduce inputs, adding another cash crop such as wheat is very beneficial. Adding a small grain will open up lots of opportunities for more diversity to plant after harvest. The cover crop can be planted in July or August, with a diverse mix of cool and warm season species from a variety of different plant families. Even on a three year rotation, this will make a significant difference in the biology of the soil.

Taking it a step further, some farmers opt to take a regenerative year and only plant cover crops to be grazed. This is the single most effective thing you can do to change your soil for the better. This approach reflects good stewardship—building soil rather than mining it, leaving the land better than we found it for future generations.

Whatever your context, start with your "why." What problems are you trying to solve? What goals do you want to achieve? Once you've identified your objectives, it's time to select the cover crop species that will work best for your operation. Like that trusted Swiss Army knife in your pocket, cover crops become an indispensable tool once you experience their benefits. The question isn't whether you can afford to use cover crops—it's whether you can afford not to.

What the Experts Say About Soil Health Principles

Keep the Soil Covered

"Soil cover is your insurance policy against climate variability. It keeps the soil cool, moist, and alive no matter what the weather throws at you." —Dr. Kris Nichols

"Keeping the soil covered is like putting armor on your land—it protects against the elements and builds resilience from the ground up." —Rick Clark

Maximize Life and Diversity

"Diversity above ground drives diversity below ground. The more species you plant, the more life you support—it's like hosting a party for your soil microbes." —Gabe Brown

"Diversity is the engine of resilience. The more players you have in your ecosystem—plants, bugs, microbes—the better your farm can handle whatever nature throws at it." —Dr. Jonathan Lundgren

Minimize Disturbances

"Disturbance burns up the soil's savings account—its carbon and organic matter. If you minimize tillage and chemicals, you're making deposits instead of withdrawals." —Dr. Jill Clapperton

Living Roots as Often as Possible

"If you don't have living roots, your soil is on life support—it's barely hanging on. Keep those roots growing, and you're giving your soil a constant supply of energy to stay alive." —Ray Archuleta

"The presence of living roots is the most important factor in soil health. They feed the microbes that build soil structure and store carbon—without them, the soil ecosystem collapses." —Dr. Christine Jones

Proper Integration of Livestock

"Livestock are the most powerful tool we have to regenerate soils, but only if we use them to mimic nature. Proper grazing management can turn degraded land into a thriving ecosystem." —Allan Savory

Context, Context, Context

"Context is king in soil health. What works in one place can fail in another if you don't account for the climate, the soil, the culture, and the farmer's reality." —Ray Archuleta