David Montgomery is a geologist and university professor who spent six months last year visiting farms in this country and abroad as part of a book he’s writing about conservation agriculture. The book builds on a reoccurring theme in Montgomery’s work — the importance of soil, and not just to agriculture but to society and human health.
Montgomery, author of the highly acclaimed book “Dirt: The Erosion of Civilization,” believes much of the current debate about agricultural practices in this country and the rest of the world is misplaced. Instead of debating the merits of high tech versus low tech or organic versus conventional agriculture, he asks us to focus on soil ecology and soil health as a way to sustain both crop yields and the soils where they grow.
The way to do that, he says, is with conservation agriculture. The Food and Agriculture Organization (FAO) defines conservation agriculture broadly, listing its three basic principles: little or no tillage, permanent ground cover, and diverse crop rotations.
“These principles really do work to restore the soil in intensive production agriculture,” Montgomery told a Natural Resources Conservation Service (NRCS) webinar audience in April. “And they’re scalable — from small-scale subsistence farms in Africa right up to big operations in the U.S.
Montgomery is a professor of Earth and Space Science at the University of Washington who specializes in geomorphology, which focuses on the earth’s topography and how it changes over time. The John D. and Catherine T. MacArthur Foundation awarded him a $500,000 “genius” grant in 2008 for his work. His best-known book, “Dirt,” examines the relation between healthy soils and healthy civilizations from the ancient Greeks to the Dust Bowl to the present day. He notes that Syria and Libya, two countries with some of the world’s most degraded soils, are also among today’s most unstable societies.
Scientists have long cited deforestation for our soil problems, but Montgomery, who made 1,402 measures of agricultural and geological erosion rates for his book, cites the plow rather than the forester’s axe for the loss. He found that the soils in many agricultural lands have eroded at the same rate as soils in the Himalaya and Andean mountain ranges, areas where geological erosion is among the highest in the world. As a consequence, the world lost a third of all its cropland to soil degradation in the 50 years following World War II.
“Agricultural soil loss is not because we farm, but it arises from how we farm,” he said. “We have access to agricultural practices that will not result in long-term losses of soil.”
The problem, he added, is that most farmers don’t use those practices.
But Montgomery is optimistic after spending time with farmers who have adopted the basic principles of conservation agriculture, even if the manner of adoption differed in each case.
“The farmers I visited used different techniques on their farms. They’re all very different, but they have greatly reduced their reliance on chemicals,” he said. “None of them — with the one exception of the Rodale Institute — were organic producers, but all of those places increased their yields and decreased their inputs and thereby made their farms more profitable.”
Montgomery also shared information he gathered for another book, “The Hidden Half of Nature,” which he co-wrote with his wife, Ann Bikle, about the “unseen half” of nature, where cells and microbes do the dirty work of protecting the plant and replenishing the soil in a place biologists know as the rhizosphere. The book also explores, from both a personal and scientific angle, how healthy soils and healthy plants make for healthy people, and how unhealthy soils are not good for crops or human health.
Montgomery described conservation agriculture not as a silver bullet for what ails agriculture but as more of a secret weapon.
“There are side benefits to restoring the soil,” he said. “It can help us feed the world in a post cheap-oil environment. It helps sequester carbon in the soil and it helps us conserve bio-diversity on that quarter of the continents that are agricultural lands.”