Regenerative Agriculture & Cover Crops

Whtie Dutch Clover sharing space with our melon crop.

Year after year we are reminded, and more so in recent years, just how important cover crops are to our farming and ecosystem.  Throughout the season, we’ve made reference to cover crops.  Earlier this year Richard gave us a glimpse into his new strategy of inter-seeding cover crops in the spaces between our raised beds for the purpose of keeping the soil in place should we get hard, fast, pounding rains that have washed our soil off fields in recent years.  We’ve learned some things about this strategy and will be evaluating improvements we can make next year.  Every year we are once again amazed at the benefits cover crops offer. Plants have a powerful ability to hold our fields together and offer many other benefits to our farming and ecosystems.  They have always been a priority at Harmony Valley Farm and we’ve known for a long time that they are beneficial.  Nonetheless, we continue to learn more about these amazing plants and what they can do for all of us.  So, for those of you who have been with our farm for many years, this week’s article is not totally new.  For those who are recently new to our farm, we want to give you an opportunity to gain insight into how we employ cover crops and why they are important.  Not all food is created equal and it’s up to you to make an informed decision as to what type of farming practices you want your food purchases to support. 

In recent years the term “Regenerative Agriculture” has been introduced in the context of finding solutions to mitigate climate change and steer our future in a more positive direction.  We’ve mentioned this term in previous articles, but here’s the specific definition of this term taken from the definition paper available in full text at regenerationinternational.org:

“ ‘Regenerative Agriculture’ describes farming and grazing practices that, among other benefits, reverse climate change by rebuilding soil organic matter and restoring degraded soil biodiversity—resulting in both carbon drawdown and improving the water cycle. 

Specifically, Regenerative Agriculture is a holistic land management practice that leverages the power of photosynthesis in plants to close the carbon cycle, and build soil health, crop resilience and nutrient density.  Regenerative agriculture improves soil health, primarily through the practices that increase soil organic matter.  This not only aids in increasing soil biota diversity and health, but increases biodiversity both above and below the soil surface, while increasing both water holding capacity and sequestering carbon at greater depths, thus drawing down climate-damaging levels of atmospheric CO2, and improving soil structure to reverse civilization –threatening human-caused soil loss.”

The following is an excerpt from a newsletter article Richard wrote in 2017 along with a few updates that he has added (in italics).  While we utilize and plant cover crops throughout the season, we are currently in the height of cover crop planting time as we race to get crops off the fields and plant cover crops so they can put down roots and maximize their growth potential before winter sets in.  This will continue to be a topic we keep at the forefront and it’s an important one for all of us to continue to learn about.  It’s going to take both more farmers adopting these practices as well as consumers who support these practices to drive positive change in our current climate predicament.

Cover Crops 101: Keep It Covered!

By Richard deWilde

A well-established cover crop planting in late fall

We’ve been using cover crops for over 40 years, mainly as a means of enhancing soil quality.  Only recently have we learned that cover crops are an important tool we can use to help mitigate climate change, both by reducing excessive atmospheric carbon as well as their role in making our soils more resilient to erratic weather conditions.  We know that soils with high organic matter hold water better in drought conditions and are able to drain better in times of excess moisture.  There are many benefits to including cover crops in farming systems and, from a farmer’s perspective, I can’t understand why every farmer wouldn’t want to plant them!Cover crops are crops we plant in our fields before and after our vegetable cash crops.  While we plant vegetable crops with the intention of harvesting them for sale, we seldom ever sell a cover crop.  There are other reasons why we plant cover crops.  Our farming system developed from the work of Rudolf Steiner, JI Rodale, and William Albrecht, early advocates of using cover crops in organic systems as a means of keeping the ground covered at all times. In theory, this is a basic principle of nature that allows us to use plants to capture solar energy from the sun to enrich the soil and prevent erosion.  We don’t like to have bare ground over the winter as it is very vulnerable to winter winds, etc and we don’t want to lose our precious topsoil!  Cover crops, in certain locations, also help to filter and purify water to keep our waterways clean, and enhance and encourage biodiversity of soil microorganisms that help us increase the organic matter in our soil as well as hold nutrients in place so they are available for the next vegetable crop that will go in that field.  While this all makes sense in theory, in practice it all comes down to management! 

Side by side cover crops planted one week apart

Many of our long term crew members understand our goals with regards to planting cover crops, but in the heat of the busy late summer and fall harvest season when we need all available hands on deck to harvest, it’s easy to put planting cover crops on the backburner to plant another day when harvest is done.  However, our crew members understand planting cover crops is a priority and work diligently to make sure they get planted as soon as possible.  As soon as we finish harvesting a crop and are done with it for the season, we prepare the ground and plant the cover crop even if it’s just two beds out of the entire field!  Time is of the essence in the fall and our goal is to give the cover crop as many growing days as possible to get established before the temperatures drop and winter sets in.  Cover crops may also be planted into a standing vegetable crop at the time of last cultivation.  This allows us to have a soil-improving cover crop already growing in the shade of a cash crop, ready to take over as soon as the cash crop is done and any remaining portion of the plants are chopped!  We use this method in crops such as asparagus, strawberries and rhubarb.  We have also expanded this practice to include our fall broccoli, cauliflower, cabbage and Brussels sprouts.  All of these already have an established cover of small clovers and grass. In these scenarios, the cover crop not only enhances the soil by increasing organic matter, but the cover crop also helps to compete with weeds and forms a mulch of sorts when the cover crop plant “winter kills.” 

Crimson clover cover crop

We have two main cover crop mixes we plant.  One mix includes plants that will “winter kill.”  Even though we may get some frosty nights and cold temperatures late in the fall, the plants in this mix continue to grow, albeit slowly.  Once the ground freezes solid their growth stops.  This mix includes Japanese millet, oats, field peas, crimson clover and a few other clover varieties. The benefit to planting a cover crop that winter kills is that the plants will not grow again in the spring and we can prepare that ground early in the spring to plant vegetable crops since the cover crop residue will work into the soil very easy without a lot of green crop plant matter to get in the way. 

Richard evaluating biodiversity in this multi-species planting

Our second mix consists of plants that can go dormant during the winter, and then resume growing again in the spring.  We plant this mix in fields that we won’t need to plant very early in the spring.  This allows us to leave the cover crop in the spring so it can grow and we can maximize its benefits.  We usually cut or chop the cover crop just before it goes to seed.  This mix consists of cereal rye, rye grass, mammoth red clover, hairy vetch as well as Alice clover and red clover.  In addition to serving as a sponge to take up available nutrients and hold them in place for next year’s crop, the rye also makes a good mulch that we cut and bale.  We take the bales off of one field and put them on another field to mulch in between beds of vegetable crops such as strawberries, tomatoes and garlic.  The clovers and vetch are able to take nitrogen from the air and fix it in the soil, which means we don’t have to apply fertilizer!  If we have excess rye grass beyond our needs for mulch, we may choose to bale some to use as feed for our cattle and goats through the winter or sometimes we just chop the crop back onto the field and work it into the soil.  This is referred to as a “green manure” crop.

Onions on raised beds with inter-seeded cover crops

We have embraced this practice and are always looking for ways to improve the system.  Over the past few years we’ve increased the diversity of plants in our cover crop mixes.  While it is more complicated to make these mixes, we appreciate the plant diversity and the different beneficial attributes each plant brings to the mix.  Each variety also supports its own unique microbes that interact with the plant at the root level.  We are also learning that there is also a synergy between organisms that multiplies the benefits exponentially.  Little is known about this interaction, but it is believed that the microbes communicate and function as a larger, very complex organism that can move water and nutrients across the field to plants in need.  How cool is that!  We will continue to invest both time and resources into planting cover crops as the benefits of doing so far outweigh any management challenges we may juggle.  Maintaining and improving the health and resilience of our soils is crucial to our ability to continue to produce vegetables with maximum nutrient quality.  We also want to do our part to maintain clean waterways, prevent soil erosion and maximize CO2 capture through our practices to do our part to mitigate climate change. 

Australian peas, with nitrogen capturing nodes on their roots.

As we continue our conversation about the future of our food system and what we want it to be, we feel it is important for you, the eater, to understand the growing system and practices we employ.  Not all food is created equal and it’s up to you to make an informed decision as to what type of farming practices you want your food purchases to support.  There are some conventional, chemical farmers who are trying to improve their soil quality with cover crops and are taking advantage of the assistance and incentives offered by the NRCS (Natural Resources and Conservation Services).  While this is good, it’s hard to make much positive headway when the cash crops being planted require chemical inputs that damage and degrade soil as well as cause other problems to the ecosystem and environment around them. 

We hope you too can appreciate the benefits of cover crops in an organic farming system and will continue to learn along with us as we learn more about their role in our future.  We also hope you will choose to support local producers who prioritize integrating cover crops into their agricultural systems.  We’ll do our part, but we need the support of consumers to turn the tide and shape our food system into the future. 

Closing Note:  If you’re interested in learning more about Regenerative Agriculture and the work being done worldwide to promote these practices, visit www.regenerationinternational.org.