Perennial Cover Crops

Is perennial ground cover a good alternative to annual cover crops?

- By John Dietz

A big reward potential is attracting research dollars to a new cover crop management variation in several Midwest states.

Continuous cropping with corn and soybeans is standard practice in the Midwest, but only about 7% of Midwest farms use cover crops, according to the University of Illinois.

Cover crop adoption is slow, and it faces challenges. Real or perceived risks may discourage adoption. These include:

• Seed, planting, and termination costs

• Fitting fall planting and spring termination into a management schedule

• Potential for lower crop yields

However, scientists and the USDA see significant long-term benefits. Success with cover crops can address concerns such as soil erosion, nutrient management, and weed suppression. Managed with no-till, corn stover can be harvested for biofuel and additional revenue.

The Perennial Option

Work on a perennial cover cropping option goes back to the early 2000s at Iowa State University (ISU), led by Ken Moore, professor of agronomy. Moore and his team focused on developing perennial ground cover (PGCs) species and management practices that avoid competition with the grain crop.

Today, PGC is an emerging option for protecting Midwest soil and water resources. In PGC systems, a ground cover is planted once but provides benefits over multiple years, ideally at a lower cost and time commitment than annual cover crops.

In short, a PGC approach could end annual seeding and termination expenses while keeping or increasing benefits for the land and the grower.

A 2024 study concludes that if adopted by large-scale Midwest corn and soybean systems, a PGC system using Kentucky bluegrass could boost net average returns by $83 per acre at the end of the second year.