Written by Pam Sherman
75 billion tons of dead, eroding soil from industrial agriculture flow into the ocean every year and more blows away, up to 100 times faster than it can be replaced.
Arid and semi-arid regions (like ours), where a half billion people live worldwide, are becoming deserts, according to a recent U.N. report linking soil degradation to climate change. Deserts exacerbate the climate crisis; IPCC Scientist Louis Verchot estimates roughly half of U.S. agricultural soils and a third of the forests are degraded.
But land can be both a source and a sink for CO2. This vicious cycle can be flipped into a virtuous one through regenerative agriculture if applied widely enough. Regenerative agriculture can also provide resilience in the face of climate extremes. How does it work? The better we understand, the more savvy and powerful we can be with every single dollar we trade for food or fashion (and much more.)
Soil health is the heart of regenerative agriculture. Improving soil health is key to long-term, sustainable agricultural production. Imagine you are a new regenerative farmer or gardener. You’d start focusing on these basic soil health practices:
Keeping the soil covered.
In our semi-arid climate this is crucial. On a hot day, the air temperature might be in the nineties, while bare soil 2” down could be 138F or more. Soil microbes, like humans, have a hard time working in these conditions. On a windy day, we can see the soil blowing off bare land, reminding many of the Dust Bowl. On a rainy day, the soil erodes downstream. To cover crop soil, mulch is good. Lots. But even better is:
Keeping Living Plants in the Soil at All Times
From sunshine and CO2 from air, living plants grow carbon-based leaves, stems, roots. They create delicious carbon-based food for their microbial partners as well, sending it through their roots. This energizes the microbes to go forage nutrients from pebbles, rocks, soil organic matter (plant or animal tissue in various stages of breakdown). They ingest many nutrients for their own use, but bring many more back to share with their plants.
The plants do not have the ability themselves to get these nutrients straight from the pebbles and organic matter. This buddy system means better health and immunity to disease and pests for crops and microbes together. Keeping cover crops in the ground all winter keeps the soil nurtured year-round.
Well-nourished bacteria and fungi also build humus, the part of soil that can retain carbon in a stable form for a long time. Advocate Graham Sait and others say “humus saves the world.”
Keeping a diversity of plants in the soil at all times.
Biodiversity is another key to a healthy agricultural ecosystem, which itself depends on the natural ecosystem. Native and crop pollinators need a wide range of native and locally adapted flowers, bushes and trees. Some flowers harbor predators which eat crop pests. The more biodiversity above ground, the more microbial biodiversity below. The more diversity, the more synergies and redundancies, the more stable and resilient the system.
Reducing or Eliminating Tillage
Tilling rips up the fungal mycelia, the thread-like growing ends of the fungi which scout for and transport nutrients and water back to the fungi and plants. This means too many bacteria and too few fungi in the soil. In our semi-arid area, we need all the fungi we can get: fungi are “carbon keepers!”
Animals with hooves, such as cows, sheep and goats, can restore soil health in ways that humans and machines have not been able to replicate. Grasslands are historically huge carbon sinks, yet are now among the most degraded ecosystems on earth. Managed holistically to mimic the way big animals interacted with grasslands over the millenia, they can restore degraded and desertified landscapes over a wide area.
How does it work? Their hoofs break the sealed, capped, mostly bare, poor soil. Their hoof prints are tiny basins which catch and hold precious water. In these hoof-basins you’ll also find manure, which acts as fertilizer, and some seeds either from the manure or planted by the farmer. When animals are moved soon to a fresh area, grasses and other plants can re-cover.
Animals also help in regenerative crop farming by eating down the cover crops in spring, readying the fields for planting. And many farmers and gardeners are grateful for decomposed manure to enrich crop fields and beds. Some prize worms as land-restorers, but not on the scale that cows, goats, sheep can achieve in the West.
Hold off on the chemical fertilizers and biocides: pesticides, fungicides, herbicides
They kill the plants’ partners, the microbes, who build the soil sponge we depend on to hold water during a flood so it doesn’t take off downstream, and which retains water for feeding thirsty plants during prolonged droughts.
Regular applications of synthetic fertilizers made with fossil fuels can supply some major nutrients to the plant; however, that makes the plant dependent on industry. The plant makes less food for microbes, which means healthy soil-building suffers. The plant also misses out on other essential nutrients that diverse, healthy microbes would have provided.
As a holistic farm manager, you’d take into account the land around your farm, your garden, forests, wildlife, birds, insects, streams and ponds, your watershed, the river into which it drains, the ocean, and your neighbors.
You’d ask yourself: is the land getting healthier every year? Am I working in a way that my relationships are also flourishing? Am I on track towards security for my family and community, a nourishing life for land and people?
Soil health is the heart of regenerative agriculture, a regenerative life. Let’s support producers who are working toward it. And restaurants, cafeterias in schools, hospitals, senior living centers, corporations, prisons and other organizations that support them.
Bio: Pam Sherman has been growing food with family for over 25 years. She writes on regen food growing locally and nationally and serves 350 CO on the Regen Ag and Local Food Systems Committee