HEALTHIER SOILS “DRAW DOWN” MORE CARBON AND HELP SAVE THE EARTH.
THERE’S SOMETHING SEDUCTIVE about manicured green grass. Collectively, however, the chemicals sprayed on lawns, parks, and golf courses represent an urgent threat to human health, pet health, and the health of our ecosystem. Lawns also use a lot of water, and storm water runs off typical lawns almost as fast as from concrete—in part because lawns usually grow on ground as dead as dirt.
The irony is that our lawns could be a secret weapon in the fight to balance Earth’s climate. We’ll get to this possibility in a moment, but first some background.
Lawns represent America’s largest irrigated crop. According to studies funded by NASA, lawns, parks, and golf courses take up more area than the state of Georgia—so changing our lawns is poten- tially a huge change to our landscape. An average lawn also requires about 200 gallons of water per day. Thus, lawns slurp up a lot of the more than 8 billion gallons of water used for irrigation each day in America. And then there are the chemicals.
In nature, no species exists alone. Healthy ecosystems require a dynamic collaboration of many species exchanging minerals, carbon, and water. When nature encounters a monocrop—such as a typical lawn—it will attempt to restore diversity through weeds, bugs, animals, and fungus: the very things that inspire fury from lawn owners.
“Bombing” a lawn with chemicals to kill pests and weeds is a practice that emerged after WWII, when chemicals that had been designed to kill people were rebranded as antipest, antiweed, and antifungal sprays for farm fields. During the 1950s and 1960s, homemakers were encouraged to spray these toxic chemical in their living rooms, to paint them on interior walls, and, of course, to sprinkle them on their lawns. Today, over 200 peer-reviewed studies link the use of these toxic chemicals to effects including non-Hodgkin’s lymphoma, ADD, lower IQ, and pediatric cancer, to name a few. Studies also show they are bad for our pets.
These chemicals also damage the trillions of microbes that live in healthy soil and bring the nutrients a plant needs to its roots. Much as we now realize that antibiotics kill our gut bacteria and damage our digestion and health, we now know that pesticides lead to dead or dormant soil microbes, which leads to weaker plants above ground, which leads to more weeds and pests, which generally leads to using more chemicals. It’s a self-perpetuating cycle. A similar scenario exists with synthetic nitrogen-based fertilizers, which are also liberally applied to lawns.
Yet the same NASA study also found that lawns do some good things. They control erosion, help to cool localized air (thus combatting the “heat island” effect), and sequester atmospheric carbon. Yes, on the whole, the U.S. grass crop “draws down” carbon—and could draw down much more carbon if our soils were healthier.
Here’s how it works: Plants take in CO2 and “respire” oxygen back to the atmosphere. About 60 percent of the carbon in the CO2 that plants “breathe in” will eventually be released back to the atmosphere. But as much as 40 percent of the carbon that plants take in can travel down the roots and get carried ever further down into the soil by microbes. The more “alive” the soil, the more carbon it can hold.
So now is the time to transform your monoculture lawn into a healthier and more resilient “multispecies” lawn that will need no toxic chemicals, no synthetic fertilizers, and little if any irrigation. It involves planting a mix of species, adding worms, fungi, natural compost, and fish emulsion, and letting your grass grow long. Your lawn will become a better carbon sink and might actually become a good thing for the planet.