Cover crops are important for the success of a modern farm or ranch. They can be seen as a drag on an ag budget, but cover crops actually add to the overall farm or ranch return on investment (ROI).

How is that possible? By definition, a cover crop is added to a crop rotation with the plan of not harvesting. So, why is that seed planted and nurtured?

The benefits of cover crops are both immediate and long-term. Many cover crops are highly effective at weed suppression. Legumes fix atmospheric nitrogen into the soil. Cover crop residue is food for beneficial microbes who increase soil nutrient cycling. Having covers always helps with soil erosion, from both wind and water.

Cover crops can be planted before or after crops; in fall and in spring. Warm season cover crops are best for early spring planting or in the fall anticipating winter kill. The cover residue acts as armor for your soil all winter. Winter covers get some growth in the fall but their real benefit is the rapid spring growth, outcompeting weeds. They can also be planted with cash crops. You don’t have to choose one way to plant covers. In fact, intercropping is one way to retain soil moisture and suppress weeds, increasing your long-term profits.

Intercropping cover crops with cash crops has numerous benefits. It creates a hospitable environment for beneficial soil organisms, retains soil moisture between row crops, and creates a symbiosis between soil organisms and plants. When you intercrop cover crops and cash crops, you create a greater ROI.

The key is choosing cover crops whose residue benefits the planned crops and that do well after the crops you’ve harvested.

The right crop – at the right time – for the right purpose…

…will give you benefits you may not have considered before in your ROI.

What Does ROI Mean with Cover Crops?

In the ag industry, ROI is usually associated with crop yields. But that’s not the only metric used by farmers and ranchers to determine the profitability of their operations. The quality of the multiple soil functions is considered when looking at long-term profits.

There are numerous ways to look at ROI. True ROI takes into account the condition of the fields, the climate and weather, and your satisfaction as an ag producer.

The financial ROI is profit. But true ROI takes into consideration your quality of life, the improvement of soil health, and the impact of your farm on the community and world. These are factors every farmer thinks about daily but aren’t usually added to the ROI.

Cover crops increase true ROI in two ways: they help create improvements in soil health and they give you more time for quality-of-life activities with your family. (1)

When you make fewer passes through the field to take down weeds, add fertilizers, and spray for pests you have more time for family. Cover crops, as part of your crop plan, decrease both human and farm ecosystem stress factors. Climate change is raising havoc with most farm plans but cover crops can future-proof your farm or ranch.

How do you go about getting the right cover crop mix in with your cash crop rotation so everyone’s happy? Start with a soil test, not just the macronutrients NPK but soil pH, microorganisms, micronutrients, and soil structure. Each cover crop species is adapted for specific soil health benefits.

Let’s look at best practices for cover crops and planting timelines for optimum ecosystem health.

Winter Cover Crops and Planting Timelines

Why plant winter cover crops?

In most parts of the United States, the tops freeze, and annual covers are winter-killed. That dead and decaying organic matter is food for beneficial organisms all winter long. That residue is a nutrient insurance policy for your operation. It’s erosion control for the freeze and thaw cycles that leave bare soil vulnerable.

Cool season cover crops that are perennials may go dormant but they don’t die. They give you needed plant growth for weed suppression in the spring. Depending on your soil type those perennial covers may be just the vegetation you need to plant your next cash crop into. 

“Planting green” can give you a jump-start on the next season. Clay soil will be less prone to compaction and sand particles will have a bit more organic matter incorporated. Both soil types benefit from additional cover crop plant roots.

How late can you plant winter cover crops? That depends on the part of the country you’re in, the amount of rainfall you anticipate, and your first frost date. It also depends on the cash crop you’re growing and its harvest date. There’s a good-sized window for most winter cover crops, typically from September through the end of October.

These are the winter cover crops we recommend for the Great Plains and the Midwest. We also recommend you use a cover crop mix for optimum soil health. The seeding rates are averages and every operation needs a custom mix and rate.

Annual cover crop species include:

• Forage oats: Best for late summer planting. Plant oats, and their quick growth will give you weed suppression, erosion control, and nutrient scavenging. The seeds can be drilled, broadcasted, or aerially applied at a seeding rate of 30-100 lbs/acre. A low rate if used as part of a cover crop mix.
• Turnips: Considered an annual but may overwinter. That’s good and bad. Good because they scavenge nutrients, especially good at nitrogen retention, and at spring termination those nutrients are available for your cash crop. Bad because they’re sometimes hard to kill in the spring. To avoid chemical termination you may need to use a combination of mowing and roller crimping. And you can always turn your cattle out in the spring to graze turnip greens. They’re highly nutritious.

• Radishes (daikon); A brassica and good at nutrient scavenging and weed suppression. They rarely survive the winter but their decaying roots are food for beneficial soil microbes. Unlike 95 percent of all plant species, brassicas have not evolved with mycorrhizal fungi. It’s best to plant any brassica, including kale, cabbage, turnips, or rapeseed with a mix that includes grasses so beneficial mycorrhizal fungi become a strong part of your soil food web.

Radishes can be planted at a seeding rate of 10 – 15 lbs/acre. It all depends on whether it’s part of a cover crop mix or used as a stand-alone to decrease soil compaction. The long tap roots break up clay soils for better soil structure and cash crop root penetration.

Perennial cover crop species include:

• Winter Rye: The most hardy of all the cereal grains. Rye is not ryegrass, it’s a grain. It can be planted as early as July if you’ve harvested and need to cover your bare soil. It can also be planted and still make it as late as November, assuming the soil isn’t frozen. 

It has all around benefits: sequesters nutrients, is a weed control, helps break up compacted soil, and is armor on your fields to stop soil erosion. And it fixes nitrogen! The planting rate depends on whether it’s part of a mix or a stand alone cover. Cover crop mixes are almost always more profitable. In a mix winter rye should be planted at around 40 lbs/acre.

• Crimson Clover: This is one of the most beautiful cover crops you can plant. It’s also a legume, so it fixes atmospheric nitrogen. It’s also extremely hardy. Plant it into corn stubble as early as possible at about 15-18 lb/acre. It can be planted into many row crops and will put on substantial growth in the fall. It blooms in spring and is a valuable crop for pollinators.

• Hairy Vetch: A great legume for nitrogen fixation. It overwinters and is an armor over your soil all winter. In the spring it grows quickly to outcompete weeds, protect soil from water erosion, and creates good soil tilth. We recommend drilling vetch 15-20 lbs.acre at 1-1 ½.in (depending on soil moisture content).

• Annual Ryegrass: Not the same thing as rye! Can create immediate soil structure improvements. The root system is huge and breaks up hardpan and scavenges residual nutrients. But beware: It can get out of hand in a field that’s wet in the spring, don’t plant ryegrass in a field that you always have to wait to get onto.It should be planted at 15-25 lbs/acre and only ¼ to ½ inch (depending on soil moisture).

There are many more cover crop species. They’ll give you the greatest ROI if you treat them like a cash crop. After all, they’re doing a lot of your work for you and need a bit of nurture to thrive. You’ll breathe easy knowing your soil is staying in place during that winter gale. And those freeze and thaws aren’t destroying soil structure. As the soil mIcroorganisms go through their life cycles all winter they’re creating soil fertility, so less fertilizer will be needed in the spring.

Speaking of spring, there are cover crops to plant before your cash crops that benefit your fields in the short and long term.

Spring Cover Crops Before Cash Crops

Many of the winter cover crops that overwintered will be beneficial come spring. Fields that are difficult to get into early will have less problems. That’s when using a blend is valuable. You get late fall growth, some winter kill, and then early spring growth. Your overwintered cover crops take advantage of spring rains.

A fast-growing spring cover crop can add green manure to a field. This is especially valuable for sandy soils that have a large pore structure. Those covers also make it easier to get into a clay soil field because their roots improve soil structure.

Many cover crops bring in beneficial predatory insects, so your overall pest populations are significantly decreased. They are a major part of an integrated pest management (IPM) plan and decrease the amount of pesticides needed.

You get benefits underground with covers because the more diverse your plant population the more diverse your soil microorganisms. When there are a lot of beneficial microbes in the plant root rhizosphere there’s very little real estate for pathogens. 

Mycorrhizal fungi, beneficial bacteria, nematodes, and protozoa populations are increased when they have a diverse food supply. The root exudates from the different plant species attract different microbes.

Here are some of the warm season cover crops we recommend. There’s no “one size fits all” ROI formula for farms and ranches. Give us a call and we can guide you in developing an effective intercropping system.

• Pearl Millet: May suppress soil-borne disease and increase soil organic matter. It’s also good mixed with forage legumes like cowpea or sunn hemp. The seeding rate is 30-40 lb/acre if broadcast.

• Buckwheat: A fast growing annual that brings pollinators. It’s very good in a strip intercropping with soybeans or other plants that need pollination. It is a good weed control. The seeding rate is 55-65 lbs/acre if the seed is drilled, more if it’s broadcasted.

• Cowpeas: A fast-growing legume with a deep tap root. Cowpeas have been grown for a long time in the south. In the Midwest and Great Plains they are a good summer cover crop. They are heat and drought tolerant and adapted to many soil types. The seeding rate is 30-90 lbs/acre and should be drilled to a depth of 1-2 inches for good soil contact.

• Sudan Grass: This grass releases chemicals that reduce populations of nematodes, something to consider if you have a root-knot nematode problem. It smothers weeds, adds organic matter, and is extremely beneficial for compacted or worn out soils. It can even handle heat and drought. It winter kills so leave the residue as a mulch, your soil organisms will be happy. The seeding rate is 20-60 lbs/acre. 

• Sunn Hemp: Fixes nitrogen, suppresses nematodes, and wins the battle against weeds. It’s a legume so doesn’t need any nitrogen fertilizer. But it does need a rhizobium inoculant if you’ve been using pesticides in your fields. You won’t have the bacteria that create symbioses with the Sunn Hemp plant roots. 

• Sunflower: It’s pretty, attracts pollinators, inexpensive, and well adapted to a variety of soils. Sunflowers are almost always found as part of a cover crop mix. Its deep taproot mines nutrients deep in the soil while also breaking up compaction.

These are some of the cover crops that are valuable for multiple ecosystem functions. You don’t have to choose between cash crops and cover crops. Interplanting them increases your ROI and your True ROI.

Summer Cover Crops for Intercropping with Cash Crops

Intercropping is one of the easiest ways to achieve true ROI. Whether you have an orchard, or vineyard, or grow row crops, interplanting cover crops improves crop performance. A study done in Idaho (2), the SARE, defines intercropping as

“…mixed cropping, companion planting, relay cropping, interseeding, overseeding, underseeding, smother cropping, planting polycultures, and using living mulch…”(3)

That’s a lot of words to say “planting two crops together.”

Intercropping has so many benefits. When you’re planting two non-competing crops, you get better resource management. Light, water, and nutrients are all used more efficiently when you have more than one crop using them. There is also a pest management benefit to covers in close proximity to cash crops.

An active soil food web benefits the cash crop and often improves yield, one aspect of ROI. The weed suppression function of cover crops is significant when intercropping. No farmer wants a lot of weed seeds in his wheat or soybean weight. Choosing low-growing covers suppresses weeds, improves soil moisture retention, and gives you a nice forage late into the season. (depending on the covers you choose).

Many studies have been done on intercropping multiple cover crop species with corn, soybeans, wheat, and cotton in the United States.

The Cover Crop Learning Curve

Adding cover crops to your cash crop rotation requires planning. The United States Department of Agriculture puts out many informational publications. We suggest you start small because there is a learning curve. 

It’s easier to plan for one cover crop but studies have shown that a mix of species creates a better ROI. The cover crop seeds will be more expensive than, for example, cereal rye alone, but the net profit from a mix of cover crop species is greater. It’s not always about yield alone.(4)

The USDA recommends cover crops and conservation tillage for both row crops and specialty crops. It is a change in mindset to plant crops you’re not going to harvest. And it does seem like those planting would drag down your ROI. But as the study by the Georgia Extension Service shows, sometimes ag can be counterintuitive.

The vast majority of agricultural operations don’t use cover crops but their production is subject to drastic climate variability. Do we have normal years anymore? One drought year or flood and your ROI is seriously impacted.

Remember true ROI? Cover crops increase true ROI in 2 ways: they help create improvements in soil health and they give you more time for quality-of-life activities with your family.

If your farm is seriously impacted, does that mean an off-farm job? Less time with family and more stress. Ag stress isn’t just about drought stress or salt stress. It’s also about worry and sleepless nights wondering about your farm’s future.

Cover crops help to future-proof your agribusiness. The USDA offers incentives to use cover crops. The Farm Service Agency oversees the USDA Cover Crop Subsidy program. Is it time to figure out the investment cost of cover crops vs erosion of topsoil and added farm inputs? The rate of return isn’t always about productivity, but it’s always about profit.

You decide how you’re going to define profit, only use financial ROI as your metric or look at the bigger picture. What do you want as your true ROI? 

We’re here to help you transition to a more profitable farm or ranch. 

1. https://www.agweb.com/news/crops/corn/do-cover-crops-pay-evaluate-your-roi-these-two-ways
2. https://www.idahofb.org/news-room/posts/ui-researcher-boosts-corn-silage-yields-by-interplanting-cover-crops/
3. https://www.sare.org/publications/crop-rotation-on-organic-farms/Guidelines-for-Intercropping/
4. https://site.extension.uga.edu/colquittag/2023/10/which-is-more-profitable-for-producers-single-species-or-multi-species-cover-crops/