David Huggins on the Global Soil Crisis
“No one has ever advanced a scientific reason for plowing.” – Edward Faulkner, Plowman’s Folly (1943)
Soil is crucial to sustaining life on our planet, feeding everything from microbes to elephants. Unfortunately, the world’s soil is being reduced to a thin dark line. Tillage and erosion are the root causes of agricultural soil loss and land degradation, creating one of the most serious environmental problems worldwide.
Tillage, the turning of soil by hand, animal or machine, leaves the soil vulnerable to wind and water erosion. It also scars soil in such a way that the soil’s ability to provide nutrients and sustain productivity is greatly diminished. The resulting soil-loss crisis threatens not only food production but many ecosystem services that provide clean water and air as well as biodiversity, thereby helping to maintain the overall health of the planet.
At the same time, with millions of new mouths to feed each year, increasing demands for bioenergy production, and mitigation of climate change through soil carbon sequestration, the demands on the world’s soil have never been greater. “The expectations of agriculture to address multiple concerns are broader now than they have ever been,” said David Huggins, USDA-ARS soil scientist and no-till researcher at a recent CSS seminar.
“The Green Revolution was directed at production of sufficient food and fiber to meet basic human needs,” explained Huggins. “Unfortunately, it wasn’t coupled with another revolution of sustainable agricultural practices.” Sustainable production methods, aimed at achieving a combination of economic, environmental and social objectives, are slowly evolving but, Huggins said, we still have a long ways to go.
In David Montgomery’s book, Dirt: The Erosion of Civilizations, the University of Washington geologist points to no-till as one of the solutions, if not the solution, to control soil erosion throughout the world. As leading researchers in no-till agriculture, the editors of Scientific American asked Huggins and WSU sustainability expert John Reganold to co-author a balanced overview of no-till. Their article was published in the July 2008 issue and is currently available online.
Huggins defined “no-till” as simply planting directly into the undisturbed residue of a previous crop. No-till drills are used to cut narrow grooves into the soil into which seeds are planted. This planting method causes minimal soil disturbance, Huggins said, thereby decreasing soil erosion, conserving water, reducing runoff, and moderating soil temperature. No-till also increases soil organic matter which improves soil structure, sequesters soil carbon, and enhances biodiversity.
Despite the simple definition of no-till, in practice it represents a radical departure from tillage-based farming and is a complex and evolving agricultural system. “Many of the tried and true tillage-based management options are lost when adopting a no-till system. Every aspect of farming has to change and adjust in order to develop and implement a viable no-till system,” said Huggins. “From my own perspective, today’s research should not support excuses for tillage, rather it should develop and promote farming strategies that give us more reasons not to till.”
–Deb Marsh
Dept. of Crop and Soil Sciences