Building Organic Matter, Storing Carbon, Combating Drought
[This article was previously published in the spring issue of The Cultivator, Cornucopia’s quarterly newsletter.]
by Marie Burcham, JD, Farm and Food Policy Analyst &
Jennifer Hayden, Ph.D, Communications and Development Director at The Cornucopia Institute
Many of the soils in the U.S. are depleted— unproductive, eroded, lacking microbial life, high in salts, and unable to retain water. This depletion has both global and local consequences that regenerative agriculture seeks to remediate.
Regenerative agriculture is not a new idea, but it is gaining steam as awareness of climate change, drought, and food security issues become more universal and pressing.
A principle goal of regenerative agriculture is to improve the land by building healthy soil, benefitting ecosystems and humanity.
One service healthy soil provides is the ability to retain water. When rain falls on depleted soil, it washes away substrate and precipitates down into the water table quickly, actions that leach the soil of nutrients and contribute to erosion and flooding.
In contrast, a healthy soil mat absorbs and stores water, combats the effects of drought, and keeps the microbiome vibrant.
Another major benefit of healthy soil is the ability to store carbon. In fact, carbon sequestration in soil is a practical way to reduce the primary atmospheric greenhouse gas, carbon dioxide (CO2), that contributes to climate change.
Due to the destruction of native grasslands, wetlands, and forests— often to make way for the soil-depleting practices of conventional agriculture—the United States has seen a precipitous drop in the amount of carbon stored in such natural carbon sinks. The key to soil carbon sequestration is supporting the soil microbiome (i.e., soil life).
Through photosynthesis, plants naturally take CO2 in from the atmosphere and convert it into the carbohydrates they need to grow. Plants send some of this carbohydrate energy down through their root systems to feed microbial soil life.
Plants act as carbon pumps, bringing the CO2 down into the soil, where it is “fixed” by soil life in a process that builds organic matter. A large fraction of organic matter is comprised of stored carbon.
Common agricultural practices destroy organic matter. Chemicals, tillage (plowing), and fallow fields all lead to the destruction of soil life, soil structure, and soil carbon.
Regenerative agricultural practices replenish depleted soils and create a system that supports soil life.
These practices include reducing or eliminating tillage (no-till) and pesticide use, planting fields year-round (cover crops), leaving plant residue on fields after harvest, adding compost, and utilizing diverse rotations and agroforestry techniques that combine crops, forestry, and livestock into one system.
Livestock raised on pasture can also aid soil regeneration and carbon sequestration when managed in ways intended to meet these goals. These management strategies seek to mimic the grazing patterns of wild herds.
Trampled grass and animal waste help build up organic matter across pastureland, serving as a valuable carbon sink. Intensive grazing practices, sometimes called “mob grazing,” rotate high densities of animals among fenced parcels of pasture.
Many of these practices are essential to organic farming— in fact, organic farmers are the vanguard of regenerative agriculture.
A contingent of conventional farmers do use no-till practices, which are regenerative, but their continued heavy use of synthetic pesticides in monocrop systems hampers soil regeneration.
Regenerative agricultural practices can reduce atmospheric CO2, while increasing resilience to both floods and drought. As an added benefit, soils built up by regenerative practices also retain their productivity without the need for synthetic fertilizers, because these soils have a rich biome that retains its mineral components.
Organic agriculture, when practiced according to the original intent of the movement, is wholly aligned with regenerative agriculture. At the heart of both is the goal of supporting soil health, which leads to long-term sustainability.
When we support organic farms that practice regenerative agriculture, we are supporting the rehabilitation of our most important shared resource: Planet Earth.