By Don Donovan
If you’re ready to take your next step on the journey to improved soil health, consider using a cocktail mix of cover crop species. I believe that’s important once you’ve become accustomed to no-tilling and to incorporating cover crops into your crop operation.
One of the key principles to building soil health and regenerating soil is to “improve biodiversity.” Most of the Corn Belt’s crop farming consists of monoculture systems — a summer annual cereal grain known as corn, and a summer annual broadleaf legume know as soybeans — and this is generally only for about half the year. The rest of the time, nothing is growing.
There are no monocultures in a native situation. The reason we have weeds in a cornfield is because Mother Nature is trying to develop a nonmonoculture environment. Given that it will be difficult for most farmers to diversify their cash cropping systems, I recommend farmers use cover crop mixes to add diversity.
The primary goal is improving diversity of soil organisms within the soil. This is managed through the diversity of plants above the ground. If you’re experienced with simple cover crop mixes, it may be time to include some more diverse mixes into your soil health journey.
Diversity means a variety of types of plants — cool-season grasses, cool-season broadleaves, warm-season grasses and warm-season broadleaf species. Diversity means cereal grains, grasses, legumes, brassicas and nonlegume broadleaf species. Diversity means time of planting. Diversity means changing your mix from year to year. Diversity means changing the time of the year if you’re using cattle to improve your soil health.
Maximizing your diversity and your investment takes careful planning. It’s important to plant mixes on a date that works for each species in the mix. This can really narrow your planting date window and is most likely to work after early-harvested crops such as wheat or silage, or even in prevented planting fields.
You could also seed various species at multiple times of the year. For example, an early July planting would allow a mix of sorghum-sudan, buckwheat, crimson clover and cowpeas. Many of these will be dormant by fall or winter, so another seeding in mid-August of winter cereal rye and brassicas such as rape, turnip and radish will provide additional diversity and resource protection.
Diversity both above the soil and below the soil is one of the keys of improved soil health. Take that step on your journey. Diversify today! Contact your local Natural Resources Conservation Service office for advice on species, seeding dates, rates and management recommendations for mixes as you continue your journey to soil health.
Donovan is a district conservationist with the NRCS. He writes from Parke County, Ind., on behalf of the Indiana Conservation Partnership.