85BACK TO THE LANDcancel out his bovine contribution to planetary disaster.
Farmers and ranchers across the country are turning
back the agricultural clock in order to convert the land
they steward into ammunition in the climate fight. In total,
cultivation sends about 8 billion tons of carbon into the
air each year. That’s nearly one-quarter of emissions—
roughly the same as heat and electricity production
combined, and far more than transportation.
Anecdotally, the United States Department of Agriculture
sees a tiny but growing number of silvopasture farms, while
other methods that suck greenhouse gases from the air—
collectively known as carbon farming— are experiencing
greater resurgences. The once- ubiquitous practice of plow-
ing, which chucks soil-bound carbon into the atmosphere
as it churns the ground, has disappeared from 21 percent of
acreage. Cover crops, typically sown in the offseason and left
in fields to decompose, are also rising in popularity.
Such practices have been on the upswing since the 1990s,
even among the large-scale operations that supply the likes
of General Mills and McDonald’s. But for the cash-strapped
midsize farmers who represent the bulk of American grow-
ers, adoption can be a challenge. While these methods can
slash costs (less tillage means less tractor fuel, and richer
soil requires fewer fertilizers), they can also risk yields.
Agronomists are working on a road map to help folks invest
in changes—and to elevate climate-conscious practices to a
place where we can feed the world’s 7.5 billion people.
Finding those answers is vital for the planet. According
to analysis from Rattan Lal, director of Ohio State Uni-
versity’s Carbon Management and Sequestration Center,
farm- based emissions trapping could get us most, if not
all, of the way to the goals of the Paris Agreement. “This
is if somebody at the United Nations turns a switch and
says, ‘Thou shalt do everything perfectly,’” he says. “Even
if we can achieve half, or a third, of what’s possible under
optimal conditions, we will have made a difference.”
×AT CHERRY FARM, A 2,200-ACRE FACILITY
affiliated with the University of North Carolina, not far from
Lanier’s ranch, biologist Tomás Moreno weaves down nar-
row aisles of organically raised cornstalks and stops at an
airtight metal chamber resting atop the soil. Slipping a sy-
ringe through a rubber gasket in the lid, he draws air that’s
percolated up from the ground. This sample is bound for a
USDA lab that will analyze its greenhouse-gas content.
As part of a long-term project kicked off in 2018, Moreno
and his colleagues repeat this process throughout the year
on plots representing more than a dozen cultivation regimes.
“We still have more questions than answers,” Moreno says,
as he shoos a giant black-and-yellow spider. Many of the
methods they track—including varying levels of tillage, cover
crops, and livestock integration—are modern-day analogs of
Neolithic agricultural life. What they find will help determine
how best to replenish the carbon the ground has lost.
Land naturally wants to hang on to carbon. Vegetation (the
more, the better) inhales the element from the sky. Roots ex-
crete some of it into the soil, feeding underground microbes,
which poop and die and aggregate with decomposing flora
and fauna to form humus, a dark, crumbly substance that is
50 to 60 percent carbon. A sponge for nutrients and mois-
ture, the material can remain stable in the soil for millennia.
Early farming scarcely disturbed this cycle. Chickens
tamed by Southeast Asian hunter-gatherers some 10,000
years ago foraged in forests rich with early crops like bananas
and mangoes. Similarly, the Amazon was once a loosely kept
garden of more than a hundred species, including cacao and
pineapple. Parts of the rainforest still hold terra preta— “dark
soil” in Portuguese— a nutrient- filled groundcover.
As societies grew and needed to scale up agricultural
production, carbon-rich landscapes became carbon-
impoverished. Farmers set fire to larger and larger tracts,
the easiest path to clear the ground— but also a huge polluter,
and a gateway to the second climate culprit, the plow.
Some 7,000 years ago, Mesopotamians developed the ard,
a wooden hoe-like implement pulled behind draft animals
to stir the earth in barley and chickpea fields. Sometime
around year zero, it evolved into an iron tool. When John
Deere introduced its ubiquitous tractors in 1918, the
practice entered an exponential growth curve.
The glinting steel of a plow blade holds obvious allure.
Digging uproots weeds that hog nutrients, water, and sun,
and it loosens the ground so tender seedlings can easily grow.SPRING 2020