Cover Crops
grasses, legumes, and brassicas planted to prevent erosion and improve soil health.
Farmer Spotlight
See how cover crops are benefiting Central Iowa farmer, Jeremy Gustafson. He has embraced a management mindset as a business strategy, too. He also sees an opportunity to leave a lasting legacy for future generations. He’s building that legacy on regenerative agriculture practices that will protect and improve his farm ground.
Benefits of Cover Crops
1. Improved Soil Health -> Yield Increases
Soil health is the ability of soil to function as a living ecosystem, which plants need to thrive! Soil health decreases when farms repeat the same crops, increase compaction of the soil, and don’t provide the right environment for microbes, worms, and other soil creatures to survive. Cover crops are one antidote! They increase soil organic matter, capture nutrients, and encourage life beneath the ground.
2. Erosion Prevention
Cover crops keep living roots in the soil and hold it in place, protecting your land investment for generations to come. ISU estimates Iowa loses 5.1 tons of soil per acre every year. For a 100 acre farm over 10 years, that’s 5,100 tons! (That’s the weight of the SpaceX Starship, a Navy frigate, 125 fully loaded semis, or 1,176 F-450 Super Duty trucks). Every ton of soil lost is money lost from your land investment.
3. Weed Suppression
Cover crops compete with weeds for growth. The residue can also block sunlight from weed seeds. Some cover crop species even produce chemicals that reduce weed seed germination. And over time, cover crops change microbes in the soil, making it a less homey place for weeds to live in. If weed suppression is your goal, it’s important to pick the right species, seeding, and termination strategies.
4. Improving The Nitrogen Cycle
Cover crops trap soil nitrate that would otherwise be washed away. Legumes produce and fix nitrogen. Unlocking this trapped nitrogen for the cash crop comes down to utilizing best management practices by the farmer. Cover crops also hold soil in place, which prevents phosphorus moving with sediment.
5. Potential to Reduce Inputs
If you’re improving soil health, fixing nitrogen, and suppressing weeds with cover crops, it makes sense that cover crops can eventually help you reduce fertilizer and herbicide costs. Depending on how you apply those inputs, you’re also reducing field passes, therefore reducing diesel and labor costs.
6. Flood and Drought Resiliency
Healthy soil has aggregates – the building blocks of soil. Aggregates and the roots of crops provide a place for water to infiltrate and be stored. During hot days, cover crop canopies also reduce heat underneath, good for soil health and for reducing evaporation.
7. Improved Water Quality
Cover crops improve water quality by reducing soil erosion. Eroding soil usually carries phosphorus with it downstream.
Cost Share Hub
Detangling cost share programs
There are millions of dollars and dozens of programs available to pay farmers for cover crops, wetlands, prairie, and more. With our tools, it doesn’t have to be confusing or overwhelming! We created a hub to learn about cost sharing and a web tool at costsharecompare.com to filter and compare cover crop programs.
Step 1: Getting Started
Determine goals, needs, and risk level
This is the most important step! Click through to see how your goals, needs, and risk level can impact your decision making process for seed, timing, and method.
Goals
What is Your goal?
1. Improved Soil Health
A multi-species is great for this, but often have to be planted early in the fall.
2. Breaking up Compaction
Brassicas are great for breaking through compaction, but not the only option.
3. Erosion Prevention
This goal usually leads to a grass species that have fibrous roots.
RiskS
What is your risk comfort?
1. Low risk
You may want start with a winter-kill cover crop like oats. It eliminates the risk of knowing when to terminate. But you don’t get the full spring coverage.
2. Medium risk
Another way to mitigate risk is to plant only one field or one portion of a field to test it out.
3. High risk
You could use a termination method and timing that allows the cover crop to grow taller for maximum organic matter. This gives you the most benefit.
Needs
Consider these topics
1.Your cash crop
Corn is known to be a bit more sensitive and doesn’t play well with rye (at least for beginners). This impacts species selection.
2. Equipment you have
If you have access to a coop interseeder or aerial broadcast, you can plant cover crops earlier, expanding your seed options.
3. Time and money
Some seed/application methods are more expensive. To save time, a winter kill species doesn’t have to be terminated (but you lose weeks of erosion protection).
Check out Iowa Soybean Association research on how cover crops impacted compaction in 2024.
Step 2: Select your species
Grasses
- Have fibrous roots that scavenge excess nitrates and fight soil erosion
- Winter kill: Oats
- Winter hardy: Triticale, cereal rye, wheat
Brassicas
- Have tuberous roots that break through compaction layers and scavenge deep nutrients
- Winter kill: Turnips, mustards, kale
- Winter hardy: Winter camelina
Legumes
- Has low C:N ratios and fix organic N with inoculated seed
- Winter hardy: harry vetch, red clover
Iowa’s most popular
- Cereal Rye: helps suppress weeds, scavenge for nutrients, reduce compaction; is easy to establish in fall
- Winter wheat: Can also be a livestock grazing supplement
- Oats: A lower risk cover crop because it kills over winter
Download NRCS fact sheets about cover crop species benefits, traits, and guidance for planting.
Step 3: Pick a Seeding Method
Drilling after harvest
- Drilling promotes uniform seeding depth and adequate seed to soil contact. However, it’s limited to later fall after crops are out.
Drilling before harvest
- This method is limited to farmers who have access to high clearance interseeders, but is one of the best methods since cover can be planted and established early
Broadcast
- This requires a higher seeding rate. It may be best for species with smaller seeds.
Aerial
- Aerial planting can be done by drone or plane and is done in late summer when cash crops begin to drop leaves. Its benefit is shifting labor to summer. The drawback is that application can be expensive and uneven.
Step 4: Pick your termination strategy
You’ll want to consider what method and timing is best for you.
Method:
- Herbicides – Low cost, easy to use, and covers many acres quickly
- Mowing, chopping, or roller crimping – Provides a mat of biomass for weed control, but you may need to manage residue
Timing:
- 10-14 days before planting – reduces impact on cash crop stand establishment, but reduces beneficial biomass; if cold, herbicide effectiveness declines
- After planting – Allows more time for biomass accumulation to suppress weeds and improve soil health, but can be risky if termination is delayed due to cold or rainy weather or cover crop gets too big.
Download Iowa Soybean Association’s “Advances in Cover Crop Management” to learn more about best practices to increase your cover crop’s ROI!
More Resources
Here are more helpful resources on prairie strips: