The concept of soil health is all about enriching your soil. Jamie Garzon, the assistant Extension professor and forage educator at UMaine, defines soil health as “the soil’s continued capacity to function as a vital living ecosystem.” Maintaining healthy soil can lead to increased plant growth, quality and yield – and reduce field costs.

Cover crops are a great way to increase soil health, as they reduce the need for added fertilization, reduce the use of herbicides and pesticides, improve nutrient cycling and soil pH and help conserve soil moisture. Cover crops reduce the presence of weeds in the soil, as they compete for resources and inhibit weed growth and germination. Cover crops strengthen the soil structure, keeping it more stable and reducing erosion.

Legumes are commonly used as a cover crop, as they offer a lot of benefits. They support nitrogen-fixation and litter decomposition; regulate greenhouse gas emissions; add diversity; contribute to forage yield and nutritive values; and they are aesthetically pleasing.

There are many varieties of legumes, and it’s important to know which one works best for your farm and your production.

Garzon talked about an experiment UMaine conducted in 2023, comparing a few cool-season forage legume varieties in the Pine Tree State. They looked at three types of red clover (Freedom MR, Medium and FSG 402), three types of white clover (Alice, Ladino and Crusade), and one type of bird’s-foot trefoil (Bull). They began looking at alfalfa as well, but quickly realized it was expensive and not a great option to consider.

In 2024, the research team took four cuts of each variety and measured the yield and quality, height and cover and amount of nitrogen-fixation. The Freedom variety resulted in the highest yield and cover, with “almost 100% of the crop” being covered, explained Garzon.

The Alice variety had a 90% coverage, but didn’t grow as much as Freedom or Bull.

Garzon explained the varieties with a lower yield are preferred because they “are not using that much nutrients.” The Alice variety “was the best [at] controlling weeds” and didn’t compete for nutrients against the cash crop. The Freedom variety fixed the largest amount of nitrogen into the soil.

UMaine plans to continue this experiment for another two years to strengthen their results.

Clovers can be used on Christmas tree farms, as long as they are properly managed. They thrive in well-drained soils with a pH of 5.5 or higher. When mowing the clover, do not cut below four inches. By leaving that height, the plant can continue to recycle nutrients and perform better during the next growth period.

Garzon recommended Christmas tree growers use Dutch white clover, mini white clover or red clover.

Establishing a cover crop system is very beneficial, but needs to be done properly. The cover crop won’t be successful if you choose the wrong species, plant it at the wrong time or improperly manage it. Make sure to do research to give your cover crops the best chance to grow, without stealing nutrients from your cash crops.