Environmental Horticulture and Design
Each January, the Ecological Farming Association hosts the largest gathering of progressive farmers, policy makers, activists, and educators in the western United States. For four days at Asilomar on California’s central coast, farmers and scientists discussed farming practices and their impact on the environment. The conference mission is to nurture safe, healthy, just, and ecologically sustainable farms, food systems, and communities.
The 2018 EcoFarm conference went beyond their usual discussions of healthy soil and nutritious crops. This year, conference attendees deliberated regenerative agriculture and carbon farming. Those practices can increase soil carbon and soil organic matter by tenfold. The results are dramatically enhanced fertility and increased crop production.
The benefits of regenerative agriculture and carbon farming reach far beyond the farm. Carbon farming captures substantial amounts of atmospheric carbon dioxide and incorporates that carbon into the soil food web. Reducing atmospheric carbon could be as simple as modifying farming practices.
Soil Food Web
Soil that is rich with organic material holds more water and contains a wide range of nutrients within the soil food web. Earthworms, beetles, grubs, small crustaceans, bacteria, and fungi form an intricate tapestry of life within the surface. Carbon and minerals from those myriad soil organisms cycle into nutrients for the next generation.
Symbiotic fungi have a unique role in soil biology. Threads of fungal mycelium form extensive interconnecting networks below the surface. Sometimes called the wood-wide web, mycelium channel water and nutrients directly into plant roots. A mycelial network can extend the reach of plant roots by an astonishing ten to one hundred times.
Above ground, chlorophyll in plants utilize carbon dioxide from the air, water from the soil, and energy from the sun to synthesize the simple sugar glucose. Glucose molecules then combine into more complex carbohydrates that feed herbivores and omnivores, including humans. Ultimately, all life on the planet depends on photosynthesis.
Fungi live below ground and do not have chlorophyll. They cannot photosynthesize the building blocks of carbohydrates. In nature’s most fundamental example of symbiosis, plant roots feed carbohydrates to the mycelium in exchange for water and nutrients.
Regenerative Agriculture for Crop Productivity
Conventional farming practices can destroy soil biology, leaving soil devoid of nearly all beneficial organisms. The soil becomes a pale tan or yellowish tan color, acting as little more than a physical substrate anchoring plants in place. Constant applications of water and fertilizer are needed for plants to survive.
Synthetic fertilizers and pesticides are deadly to soil biology. Earthworms vanish. Microbial life decreases, and the soil food web can almost completely disappear.
Each time a field is tilled, the mycelial network is ripped into fragments, unable to channel water or nutrients into plant roots. Tilling also damages soil aggregates. According to the USDA National Resources Conservation Service:
The space between the aggregates provide pore space for retention and exchange of air and water.
Fungal mycelial growth binds soil particles together more effectively than smaller organisms, such as bacteria.
Aggregate stability declines rapidly in soil planted to a clean-tilled crop.
After years of tillage, topsoil is reduced to a powder with hardpan below. Deeper tilling simply creates a deeper hardpan.
Regenerative agriculture and carbon farming focus on rebuilding soil organic material. Eco-Farm’s no-till and low-till famers discussed practices for disturbing the soil as little as possible. Their soil is always covered with market crops, cover crops, or mulch. Soil biology is protected from baking summer sun. Consistent moisture and cooler temperatures favor proliferation of soil biology.
Farmers and scientists reported dramatic improvements in just a few seasons. Costs for soil amendments are minimal. Water use is substantially less. Weed problems nearly disappear. Soil roots are kept nearer the optimum 70° temperature. Crop productivity increases two to three times over conventionally managed fields.
Regenerative Agriculture for Carbon Capture
In conventionally farmed soils, carbon content can drop to less than 1%. Around the globe, carbon from the soil food web has been released into the atmosphere.
Using regenerative agriculture practices, both soil carbon and soil organic material can increase by an order of magnitude. The most important steps toward regenerative agriculture can save farmers both time and money.
No-till or low till practices. Cover crops or mulch are left in place from season to season. New seeds or plants are placed with minimal disturbance.
No synthetic chemicals. The soil food web will provide all or nearly all nutrients that are needed by the crop. If additional nutrients are needed, modest additions of compost, compost tea, and calcium are generally sufficient. Worm compost is an exceptional source of fertility and beneficial biology.
Research on Regenerative Agriculture
David C. Johnson, Ph.D. of New Mexico State University was an EcoFarm keynote speaker. His experimental farm plots were treated with a fungal-dominated compost. The results were impressive. According to Dr. Johnson:
Once you improve your soils to the point they have a higher carbon content and a better soil microbial structure, then, if you can grow twice the amount of food on half the amount of land, you can reduce the amount of land you farm, and in doing this, you can cut your water usage. Agriculture currently uses about 80 percent of our freshwater resources.
Dr. Johnson is quick to smile when discussing his research. His biological processes capture ten times more carbon that any other carbon sequestration method currently being studied.
It will change the way we approach agriculture. And, my waste product from reducing atmospheric CO2 concentrations is food. Can you beat that?
In a short video (https://vimeo.com/237134837), Dr. Johnson introduces the potential for carbon farming to revolutionize agriculture and reduce atmospheric carbon dioxide.