Cover Cropping on the Farm
by Ivana Zivkovic
Conventional farming methods can be destructive and have long-lasting consequences on the natural environment. The vegetables we grow inherently steal nutrients away from the soil they’re grown in and subsequently pack these nutrients into their fruits, leaves, stems, and roots. Here at Forts Ferry Farm, we want to produce the most nutrient-dense vegetables naturally possible, but in order to do so, we must acknowledge the vegetables’ dependency on the health and vitality of our soil, and take steps to ensure its well being for years to come.
Vegetable plant cells use the nutrients provided by the soil to create vitamins and other complex molecules that our bodies can absorb. When we harvest any vegetable, we are taking with it small quantities of over 17 essential nutrients that make plants and consequently our bodies healthy. While there is an abundance of nutrients in the world’s soil and atmosphere, plants cannot access the nutrients without the relationships formed by soil, beneficial soil life, and plant roots.
Cover cropping is one of the critical steps we take to give back to the land we rely so much upon. In this journal entry, we’ve collected some notes about the use of cover crops here at the farm and describe some of the processes we take to care for the land we grow on.
What is a cover crop:
A marvelous thing! It is intentionally planted vegetation used to build soil, reduce soil compaction, and give land a break from vegetable production/extraction on farms and home gardens alike.
Cover crops:
Increase aeration, organic matter, and nutrient availability
Aid in the creation of stable soil aggregates
Welcome in life (bugs, toads, and fungi)
Break up disease cycles in plants
(by increasing the diversity of bacteria able to cope with incoming pathogens)Provide a break in tillage for the land
Decrease chances of erosion, especially over the winter months
There are hundreds of cover crops that make nutrients available with the help of living creatures in the soil. Plants and creatures in the rhizosphere work to metabolize and transform nutrients, making them available to vegetables that we enjoy.
If we didn’t plant cover crops, our soil would be bare in the winter and subject to several types of erosion. In the spring, as the snow melts, we would find the field to be sunken and compacted. Streams would run down natural slopes and deposit sand and silt elsewhere. As the season progressed, we would find the land unable to retain water after a heavy rain, leaving stunted vegetables in puddles of standing water and the soil greatly unbalanced.
Erosion can happen on small farms and to an even greater extent in conventional agriculture. According to SARE, rapid loss of topsoil happens rather early — as much as 20% of the topsoil can be lost, displaced, and degraded within the first 5 years of crop production. It is an important time to advocate for soil health, as it is truly the foundation for life as we know it.
“George Washington Carver” 1942 by Betsy Graves Reyneau.
Much of this knowledge is thanks to George Washington Carver, who invented crop rotation and principles of multi-purpose cover cropping as part of a self-reliant and deep care for the soil. He has made it possible for many farmers and gardeners to break reliance on chemical industries and realize that much of what is needed in farming is inherent in the land.
A timeline of cover crops we used this year
Including a list of seeding windows that worked well for us in Zone 5B
A Look at Ray’s Crazy Summer Mix
A diverse mix of Cowpea, 2 types of Sorghum Sudan Grass, Daikon Radish, Pearl Millet, Peredovik Sunflower, and T-Raptor Brassica. (LEARN MORE)
Cover crops are meant to be planted together! We often plant 1-2 types of vegetable per bed (a micro-mono culture!). Diversifying an agricultural field is extremely important.
It ensures that:
Plants have resilience during drought, flood, and variable weather
A diversity of soil beneficial bacteria are being supported
The ground is covered if certain cover crops fail
Several aspects of soil aeration and nutrient cycling are being encouraged
The crops in this mix worked together to create a network of relationships and support systems. Here’s how it went for us:
How it went:
A flock of starlings came out to visit our first planting and ate all of the sunflower seeds. The brassicas came in and flowered quickly. This field was prone to flooding in the past and we could see the compaction because of height variation in the sudan grass.
The orchard cover crop was similar; there weren’t too many sunflowers present and the sandy, quick draining soil made it hard for certain crops to grow. It was a very dry summer. Sorghum sudan grass, cow pea, and flowering brassica were prominent.
Our post-garlic seeding turned out to be our best stand. With daikons over 24 inches long and an even spread of sunflowers. The greens were lush on all crops whereas some of the other stands developed alternaria leaf spot.
In all scenarios, the ground was completely covered and the land benefited from the long season of coverage. The daikons will die back in the cold winter, leaving a food source for many soil creatures that will continue to aerate the soil.
There is a lot of responsibility involved when land is opened up for agricultural production. Cover cropping is something anyone can do at any scale of growing. If you’re looking to cover your garden over winter, peas and oats will be an easy go-to. For summer cover, versatile mixes are available from seed sources below and it’s always fun to throw in some flowers.
It can take 5 to 10 years to see major changes in the soil, but we’ve already begun to see improvement in soil health at Forts Ferry Farm because of cover cropping.
Successful farming depends on a multitude of factors, some controllable and some not. Some of these factors include drought, soil health, timing, seasonal changes, pests, labor, land history, fungus, erosion, and on and on. Cover cropping is one aspect of a larger effort to promote healthy growing environments for our crop production. As with most things here at this farm, we are always experimenting and using the information we gather every year to educate ourselves and make better decisions for both the land and our operation!
Interesting Side Notes:
If we are losing 2% organic matter (top layer of soil) annually on a 1 acre piece of land, we are losing 1200lbs of organic matter per year (Courtens 2010)!
Quorum Quenching & Sensing-- Cover cropping increases diversity of bacteria in soil. When enough of one bacteria are present, they communicate with each other and with plants, triggering genes in plants. Beneficial and pathogenic bacteria both have this ability, but often beneficial bacteria can help plants change growth patterns (root extension, symbiotic relationship formation, gene signaling) to avoid pathogens. Bacteria and plants collectively decide how interactions will go down through population and genetic responses.
All plants sequester carbon so covering land is directly minimizing your impact on the climate. Bare soil produces heat and water vapor which directly contribute to global warming.
Cover Crop Seed Sources:
Johnny’s Seeds
Fedco
Highmowing
Lakeview Organics
Ernst Conservation Seed
Additional Resources:
Click HERE for a super helpful resource for remediating soils with plenty of information about what different plants do as cover crops.
Cover Crops can be expensive. Click HERE for an extensive (248 pages!) document from SARE about the functions of different cover crops. If that’s too long HERE is a list of all of the charts and tables from the handbook.
Resource for calculating cover crop mixes from Penn State (LEARN MORE).