Author:| Published: April 14, 2017
Most of us don’t think much about soil, let alone its health. But as Earth Day approaches, it’s time to recommend some skin care for Mother Nature. Restoring soil fertility is one of humanity’s best options for making progress on three daunting challenges: Feeding everyone, weathering climate change and conserving biodiversity.
Widespread mechanization and adoption of chemical fertilizers and pesticides revolutionized agriculture. But it took a hidden toll on the soil. Farmers around the world have already degraded and abandoned one-third of the world’s cropland. In the United States, our soils have already lost about half of the organic matter content that helped make them fertile.
What is at stake if we don’t reverse this trend? Impoverished trouble spots like Syria, Libya and Iraq are among the societies living with a legacy of degraded soil. And if the world keeps losing productive farmland, it will only make it harder to feed a growing global population.
But it is possible to restore soil fertility, as I learned traveling the world to meet farmers who had adopted regenerative practices on large commercial and small subsistence farms while researching my new book, Growing A Revolution: Bringing Our Soil Back to Life. From Pennsylvania to the Dakotas and from Africa to Latin America, I saw compelling evidence of how a new way of farming can restore health to the soil, and do so remarkably fast.
These farmers adopted practices that cultivate beneficial soil life. They stopped plowing and minimized ground disturbance. They planted cover crops, especially legumes, as well as commercial crops. And they didn’t just plant the same thing over and over again. Instead they planted a greater diversity of crops in more complex rotations. Combining these techniques cultivates a diversity of beneficial microbial and soil life that enhances nutrient cycling, increases soil organic matter, and improves soil structure and thereby reduces erosive runoff.
Farmers who implemented all three techniques began regenerating fertile soil and after several years ended up with more money in their pocket. Crop yields and soil organic matter increased while their fuel, fertilizer, and pesticide use fell. Their fields consistently had more pollinators — butterflies and bees — than neighboring conventional farms. Using less insecticide and retaining native plants around their fields translated into more predatory species that managed insect pests.
Innovative ranchers likewise showed me methods that left their soil better off. Cows on their farms grazed the way buffalo once did, concentrating in a small area for a short period followed by a long recovery time. This pattern stimulates plants to push sugary substances out of their roots. And this feeds soil life that in return provides the plants with things like growth-promoting hormones and mineral nutrients. Letting cows graze also builds soil organic matter by dispersing manure across the land, rather than concentrating it in feedlot sewage lagoons.