Ask the Indiana NRCS Expert: Cover Crops

Why plant cover crops?

Why indeed! Why is always the first question I want a farmer to ask and answer as they consider adding cover crops to their system. Once you answer why, then you can get to the nitty gritty questions of “how, what and when.” But without your why, the rest won’t fall into place. Everyone’s why will be different, and it can be as simple as because I have erosion, because I have compaction issues, or it can become more complex like because I want to pass the farm on to the next generation better than when I got it. You’re why may change from season to season but your decision to use cover crops becomes stronger as you see how they can improve your cropping system.

What should you consider before planting cover crops? And do you have any tips for someone trying cover crops for the first time?

There are so many things to consider! Sometimes as I go through the list of considerations it can feel overwhelming to a farmer just staring out with cover crops. My goal in conversations with farmers is to work tirelessly to ensure they have success the first time out of the gates. If their first experience with cover crops is a failure, it is difficult to convince them to try again. That is why going into cover crops with eyes wide open is so important. Here is just a brief list of things to consider:

• What is your current crop?
• What is next year’s planned crop?
• What type of weed pressure does the field have?
• What herbicide have you used? Be aware of residuals and carry over!
• What moisture conditions are you dealing with at cover crop planting and termination?
• What cover crops to plant.
• How to plant the cover crop.
• When to plant the cover crop.

A few other things to think about here are to start small and learn. Expand your acres as your experience and comfort level increase. Lastly, be patient and stick with it. You didn’t stop growing corn the first time you had poor emergence, or a drought affected your yields. Find a way to learn why something didn’t work instead of blaming the cover crop.

Cover crops can help farmers reach a lot of different goals from improving soil health to providing livestock forage. How do you determine which cover crop or cover crop mix to use based on conservation goals?
Once I’ve worked with a farmer to better understand his/her goals and been on site to get a good understanding of site-specific conditions, I start to contemplate the different types of cover crops and how they meet those goals.

• High biomass cover crop species are great for erosion control, building organic matter and controlling weeds.
• Fibrous plant roots do a great job of wrapping around and holding together soil aggregates, especially in the top 12 inches of soil. Grasses and grain crops like oats, cereal rye, annual rye grass and sorghum sudan grass are excellent examples of plants with fibrous roots. These roots help to control erosion, sequester carbon and facilitate nutrient cycling. Fibrous roots are pumping lots of carbon into the soil to feed soil microbes and these microbes are the backbone all of these improvements are built on.
• Deeper tap roots help to address compaction and build organic matter.
• Legumes like clovers and field peas can add nutrients to the soil and lower the carbon to nitrogen ratio of your cover crop biomass.
• If you need to feed livestock, thinking about cover crop palatability and grazing are important to consider.

I like to read about cover crops and their uses in Managing Cover Crops profitably, a book produced by SARE and that has since been adapted to a website called the Midwest Cover Crops Council (MCCC). 

What are the biggest management challenges when planting and terminating cover crops?
The biggest challenge is being aware of and OK with the fact that even with the best plan in place, mother nature can make it difficult or impossible to implement! That is why we always talk about having back-up plans.

One of the things I like to do is to step farmers into cover crops. So, this would mean starting with a cover crop mix, like oats and radish, that will winter kill. It gets the farmer comfortable thinking about the front end of this process — planting the cover crop. He or she can really focus on building skill using a drill or getting familiar with custom seeding work but won’t have to worry a ton about what is going to happen next spring. After that first success, the next step would be to try a cover crop that overwinters, like cereal rye. You’re already familiar with seeding options but now you need to think about how to manage the back end — a living cover crop that needs to be terminated next spring. In this second step, I would advise to terminate early while that cover crop is in the vegetative stage. A third step would be to use cereal rye again but allow it to grow and wait to terminate until right before planting. As you step into using cover crops, there can be management challenges but you’re taking them on in small increments and planning ahead versus trying to figure out a completely new system all at once.

How does NRCS help farmers plant cover crops?

We support farmer by providing guidance for what cover crops to seed as well as how and when to seed with our guidance documents and site-specific planning worksheets. All of this is based on their why, the site conditions and the resource problems that are planned to be addressed.

Of course, our conservation programs are a major way in which we help farmers plant cover crops. This financial assistance is integral to being able to try and adopt new conservation practices, especially management practices like cover crops. This financial assistance helps to mitigate risk while a farmer learns how to fit the practice into their operation. Conservation programs like the Environmental Quality Incentive Program (EQIP) and Conservation Stewardship Program (CSP) are essential conservation programs. But financial assistance void of strong technical assistance is just a paycheck and that is not what our agency is about. Our goal is to provide strong technical assistance in combination with financial assistance. We must be in the field learning with our farmers so as we continue to provide technical assistance it is based on sound science and local in-field knowledge.