Written with Paul Van Mele

In the opening scenes of the film, “Living Soil,� we see the Dust Bowl: the devastated farmland of the 1930s in the southern plains of the USA. Thirty to fifty years of plowing had destroyed the soil, and in times of drought, it drifted like snow.

As the rest of this one-hour film shows, there is now some room for optimism. Nebraska farmer Keith Berns starts by telling us that most people don’t understand the soil, not even farmers. But this is changing as more and more farmers, large and small, organic and conventional, begin to pay attention to soil health, and to the beneficial microbes that add fertility to the soil. Plants produce carbon, and exchange it with fungi and bacteria for nutrients.

Mimo Davis and Miranda Duschack have a one-acre city farm in Saint Louis, Missouri. The plot used to be covered in houses, and it was a jumble of brick and clay when the urban farmers took it over. They trucked in soil, but it was of poor fertility, so they rebuilt it with compost, and cover crops, like daikon radishes. Now they are successful farmer-florists—growing flowers without pesticides so that when customers bury their noses in the bouquet, it will be as healthy as can be.

A few scientists also appear in the film. Kristin Veum, USDA soil scientist, says that soil organisms are important because they build the soil back up. Most people know that legumes fix nitrogen, but few know that it’s the microbes in association with the plants’ roots that actually fix the nitrogen from the air.

Indiana farmer Dan DeSutter explains that mulch is important not just to retain moisture, but also to keep the soil cool in the summer. This helps the living organisms in the soil to stay more active. Just like people, good microbes prefer a temperature of 20 to 25 degrees Celsius. When it gets either too hot or too cold, the micro-organisms become less active. Cover crops are also important, explains DeSutter, “Nature abhors a mono-crop.� DeSutter plants cover crops with a mix of three to 13 different plants and this not only improves the soil, but keeps his cash crops healthier.

Nebraska’s Keith Berns plants a commercial sunflower crop in a mulch of triticale straw, with a cover crop of Austrian winter pea, cowpeas, buckwheat, flax, squash and other plants growing beneath the sunflowers. This diversity then adds 15 or 20 bushels per acre of yield (1 to 1.35 tons per hectare) to the following maize crop. Three rotations per year (triticale, sunflower and maize), with cover crops, build the soil up, while a simple maize – soy bean rotation depletes it.

Adding carbon to the soil is crucial, says DeSutter, because carbon is the basis of life in the soil. In Indiana, half of this soil carbon has been lost in just 150 to 200 years of farming, and only 50 years of intensive agriculture. No-till farming reduces fertilizer and herbicide costs, increases yield and the soil improves: a win-win-win. This also reduces pollution from agrochemical runoff.

As Keith Berns explains, the Holy Grail of soil health has been no-till without herbicides. It’s difficult to do, because you have to kill the cover crop to plant your next crop. One option is to flatten the cover crop with rollers, and another solution is to graze livestock on the cover crop, although he admits that it’s “really hard� to get this combination just right.

USDA soil health expert Barry Fisher, says “Never have I seen among farmers such a broad quest for knowledge as I’m seeing now.� The farmers are willing to share their best-kept secrets with each other, which you wouldn’t see in many other businesses.

Many of these farmers are experimenting largely on their own, but a little State support can make a huge difference. In the 1990s in Maryland, the Chesapeake Bay had an outbreak of Pfiesteria, a disease that was killing the shellfish. Scientists traced the problem to phosphorous, from chemical fertilizer runoff. Maryland’s State Government began to subsidize and promote cover crops, which farmers widely adopted. After 20 years, as Chesapeake Bay waterman James “Ooker� Eskridge explains, the bay is doing better. The sea grass is coming back. The blue crab population is doing well, the oysters are back and the bay looks healthier than it has in years.

Innovative farmers, who network and encourage each other, are revolutionizing American farming. As of 2017, US farmers had adopted cover crops and other soil health measures on at least 17 million acres (6.9 million hectares), a dramatic increase over ten years earlier, but still less than 10% of the country’s farmland. Fortunately, triggered by increased consumer awareness, these beneficial practices are catching on, which is important, because healthier soil removes carbon from the atmosphere, reduces agrochemical use, retains moisture to produce a crop in dry years, and grows more food. The way forward is clear. Measures like targeted subsidies to help farmers buy seed of cover crops have been instrumental to help spread agroecological practices. Experimenting farmers must be supported with more public research and with policies that promote healthy practices like mulching, compost, crop rotation and cover crops.

Watch the film

Living Soil directed by Chelsea Wright, Soil Health Institute

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