Cover Crop FAQ

Why plant Cover Crops? Cover crops have been around for a long time. Here are some reasons to plant them:

• Prevent Erosion: Dense root systems hold soil in place, significantly reducing wind and water erosion.
• Improve Soil Health: Cover crops can increase soil organic matter, which improves soil structure, aeration, and water retention. For each 1% increase in organic matter, soil can hold approximately 25,000 more gallons of water per acre.
• Boost Nutrient Availability: Legume cover crops like clover and vetch can 'fix' atmospheric nitrogen, adding between 40 to 200 pounds of nitrogen per acre to the soil for the next crop.
• Increase Cash Crop Yields: Over time, improved soil health and nutrient cycling can lead to more resilient crops and higher, more stable yields.
• Suppress Weeds and Pests: A thick stand of cover crops can outcompete weeds for light and resources, and some varieties can disrupt the life cycles of pests and diseases.

What types of seed do you plant? The types of cover crop seeds varies dramatically by both region of the country and when you are planting. We strongly suggest you consult your local soil and water team or you university extension office for suggestions on what type of seeds work best in your area. Some farmers will plant one type of seed while others use “cocktail” mixtures of seeds. 

While consulting your local extension office is always recommended, here's a general breakdown of common types:

• Grasses (e.g., Cereal Rye, Annual Ryegrass): Excellent for scavenging leftover nutrients, preventing erosion, and building soil organic matter with their extensive root systems.
• Legumes (e.g., Crimson Clover, Hairy Vetch, Winter Peas): Known for fixing atmospheric nitrogen, which can reduce fertilizer needs for the following cash crop.
• Brassicas (e.g., Radishes, Turnips): Great for breaking up compacted soil with their deep taproots and scavenging nutrients from deep in the soil profile. Many farmers use 'cocktail' mixes that combine species from different categories to achieve multiple benefits simultaneously.

When do you plant cover crops? Again, the answer varies by region. Some of the most popular times to plant cover crops are after harvest using seeders mounted on some type of tillage equipment or harvesting equipment, inter-seeding cover crops into standing crops from June to August and at the time of planting cash crops. A lot depends on the type of seed and the equipment you are using.

How do you terminate your cover crop prior to the next planting season? 

Termination is a critical step to ensure the cover crop doesn't compete with your cash crop. The best method depends on your cover crop species, equipment, and farming system (e.g., conventional, no-till, organic).

• Winter Kill: Some species, like oats or radishes in colder climates, will naturally die off over the winter.
• Tillage: Plowing or disking the cover crop into the soil is a traditional method, but it can negate some of the soil health benefits.
• Roller-Crimping: A roller-crimper is used to flatten the cover crop, forming a thick mulch that suppresses weeds. This is a popular method in no-till systems.
• Herbicides: Spraying is a common and effective method, but requires careful selection of herbicides and proper timing.
• Planting Green: Some farmers plant their cash crop directly into the living cover crop and terminate it shortly after. This advanced technique can maximize soil health benefits but requires careful management.

What is the effect of herbicides on cover crops? Read the label on your herbicide to determine the residual holdover for the type of seeds you are planning to plant. You can access additional information from the suppliers of your herbicide and seed or your local university extension office.