The key to building soil health is photosynthesis, hands down. All life depends on this beautiful synergy between sunlight, water, plants and microorganisms. Our mission as farmers, as land stewards, is to constantly promote and encourage diverse growth in order to continue this cycle of life. I am excited to tell you about the importance of cover crops and how we utilize them to maximize photosynthesis at Gaining Ground. 

What is a cover crop? 

A cover crop is a specific crop or mix of crops that is planted intentionally to nourish the soil and not to be harvested. To me it symbolizes true reciprocity as it has the ability to give back and replace nutrients from the prior vegetable crop planted.

The act of cover cropping is important as it invests in the long-term health of the soil and allows for us farmers to introduce diverse root systems and biomass instead of growing just a handful of vegetable plant families year after year. These crops can increase biodiversity, offering beneficial organisms a refuge both below and above soil. 

Cover crops prevent and slow the erosion of topsoil. They can also smother weeds and help break up pest and disease cycles. They can even break up compaction over time! Finally, cover crops increase soil organic matter which in turn strengthens the availability of water. The soil’s ability to retain water is increased as well as the ability to drain water when there is an excess as we have seen this year. 

What are the types of cover crops?

In essence any plant on earth can be considered a cover crop, but for the purpose of this writing, I will focus on some staple mixes that we use here at Gaining Ground in the Northeast. 

When deciding what cover crop to use, it is helpful to ask what is your purpose? What are you trying to achieve within your ecosystem both short and long term? Some other questions might include, how much time do you have? Is your soil compacted? What was previously grown on that land? What will you grow after the cover crop? Are there a lot of weeds? How will you terminate them? What are the issues within your soil? 

Here are a couple of cover crop cocktails that we use here at Gaining Ground:

1. Fall Winter Kill Mix: Oats, Field Peas, Bell Beans, Tillage Radish

We seed this mix anytime from late August to September 15th with a mix of the Jang seeder and Earthway seeder (provide links to these so readers know what they are?). We make sure to get good soil contact and to water the seeds for a little bit each day until they germinate. This mix is one that can break up compaction, fix nitrogen, and grow immense biomass and is one that will die with a number of hard frosts in Massachusetts. In the spring it is easily raked off to become a mulch for the pathways and can be directly seeded into with crops such as carrots or arugula. This is a nice beginner cover crop!

2. Fall Winter Mix: Winter Rye and Crimson Clover 

We seed this mix in September and October but not past October 15th in Concord, MA as it needs enough warmth and sunlight to establish well. These special plants will continue to photosynthesize all winter long, which is the ideal scenario for nature. The rye is an amazing biomass producer with roots reaching 4 feet down into the soil, scavenging for nutrients and building relationships with microbes. The clover will fix nitrogen and also offer flowers for pollinators in May. In our no till system we crimp this mix down at the very end of May when the plants are both flowering using a board and rope. We then pull silage tarps over it for about a week to terminate it. It becomes an in-place mulch into which we can transplant winter squash! 

3. Summer Mix: Cow Pea, Sunn Hemp, Sorghum Sudan Grass

This mix is a heat lover and can build soil health due to its immense biomass and nitrogen fixing capacities, taking advantage of full sunlight at the height of the season. We generally grow this mix anytime from early June to Mid August. These crops will die with any sign of frost and will prevent erosion all winter long. In the spring they will be ready to plant with a quick raking. 

I invite you all to look around your neighborhoods for everyday examples of how our ecosystem is laid out. Observe your local plant life, learn about new plants. Get to know their habits, textures, smells, and even tastes. And also, offer gratitude for the work that plants do for us on a daily basis without question. Happy cover crop seeding!