A recipe for fighting climate change and feeding the world
Scientists hope this new kind of perennial grain offers a taste of what environmentally friendly farming could look like
“It’s so different from anything I’ve baked with,” says my baking partner, Jenny Starrs.
We’re standing in the tiny kitchen of my D.C. apartment, examining palmfuls of a dark, coarse, rich-scented flour. It’s unfamiliar because it was milled from Kernza, a grain that is fundamentally unlike all other wheat humans grow.
Most commercial crops are annual. They provide only one harvest and must be replanted every year. Growing these foods on an industrial scale usually takes huge amounts of water, fertilizer and energy, making agriculture a major source of carbon and other pollutants. Scientists say this style of farming has imperiled Earth’s soils, destroyed vital habitats and contributed to the dangerous warming of our world.
But Kernza — a domesticated form of wheatgrass developed by scientists at the nonprofit Land Institute — is perennial. A single seed will grow into a plant that provides grain year after year after year. It forms deep roots that store carbon in the soil and prevent erosion. It can be planted alongside other crops to reduce the need for fertilizer and provide habitat for wildlife.
In short, proponents say, it can mimic the way a natural ecosystem works — potentially transforming farming from a cause of environmental degradation into a solution to the planet’s biggest crises.
[Try the recipe: Kernza sourdough]
This summer I traveled to Kansas, where I met the scientists who are trying to make Kernza as hardy and fertile as traditional wheat. I visited the farmers who must figure out how to grow it effectively. And I invited my friend Jenny, the founder of artisan baking company Starrs Sourdough, to help me make a loaf of Kernza bread.
Kernza has a long road from the laboratory to the kitchen table. It will be even harder to transform the farming practices that humans have relied on for most of history. But if the scientists, farmers and processors are successful, perennial foods might one day be available on grocery store shelves — and the bread that Jenny and I are baking could offer a taste of what’s to come.
The first step in Jenny’s bread recipe is making the “levain” — a mix of flour, water and yeast that ferments for a long time, producing lots of air bubbles and tasty lactic acid.
While the microbes chow down, Jenny and I compare the whole Kernza to some wheat kernels she has on hand. The Kernza grains are smaller, and they contain less of the gluten protein that makes traditional wheat good for baking bread.
“Obviously, bread flour is awesome,” Jenny says — after all, humans have been perfecting it for nearly 10,000 years.
At the end of the last ice age, in the fertile river valleys of the Middle East, China and Mexico, people found they could sustain themselves more easily by cultivating crops. Three annual grasses — wheat, rice and corn — became the foundation of human diets and human civilization.
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Freed from the need to rove the landscape in search of food, people settled down and constructed cities. Religions and school calendars were structured around the rhythms of farming: planting seeds, helping them grow, harvesting grains and then tilling the soil to prepare it for the next round of planting. Generations of careful breeding improved crops’ taste and yield, and ever- stronger fertilizers have made farms still more productive. The population boomed.
But the planet has paid the price. The practice of tillage — churning the ground to destroy weeds and facilitate the planting of next year’s crop — has depleted the very earth from which our food is grown. It breaks up clumps of organic matter and exposes them to the sunlight, releasing carbon into the atmosphere. Tilled soil is less able to hold water, causing nutrients and other particles to run off into rivers, lakes and the sea.
Research suggests that the world’s soils are now eroding 100 times faster than new soil can form, and an estimated 33 percent of soil is so degraded that its ability to grow crops is compromised. Meanwhile, monoculture — the strategy of sowing huge fields with a single crop — achieves higher yields but also puts more pressure on soil and increases the risk that plants will succumb to pests or disease.
Many of humanity’s solutions to these problems also create other issues, Land Institute researchers say. Fertilizer can counter soil degradation, but it pollutes waterways and produces nitrous oxide, a potent greenhouse gas. Pesticides might reduce threats from insects, but they destroy other vital species. Cover crops will curb erosion, but they can be difficult to plant and maintain.
And modern farming is hugely carbon intensive. Factoring in fuel for machinery and food transport, methane produced by belching livestock, and the carbon that’s lost when ecosystems are converted to cropland, agriculture accounts for about a quarter of humanity’s annual planet-warming emissions.
Yet farms are also threatened by climate change, which will increase the risk of prolonged droughts and catastrophic floods.
In Kansas, one of the nation’s leading producers of wheat, these problems are on full display. The state loses an estimated 190 million tons of its rich topsoil each year. Climate change has made Kansas summers hotter and drier, but also makes rainstorms more intense. The state’s farmers are among those most at risk of losing crops as a consequence of human-caused warming.
“It’s a disaster,” Tim Crews, the Land Institute’s lead soil ecologist, tells me one damp day in June. Our shoes squelch in the mud as he leads me around the institute’s Salina, Kan., campus. As we talk, the rain is almost certainly destabilizing soil and washing it into surrounding streams.
Crews sweeps his hand out, as if to indicate not only the farm fields across the road but the entire U.S. agricultural system.
“This is the ecosystem that feeds us, and it has just been nuked,” Crews says. “Is this really the best we can do?”
Land Institute scientists disagree about how to describe what they’re proposing. Is it a natural evolution from the past 10,000 years of annual agriculture? Or something more like a midcourse correction?
Rachel Stroer, the Land Institute’s president, calls it a “paradigm shift.”
“Instead of an annual monoculture,” she says, “we’re trying to create a perennial polyculture” — cultivating diverse mixes of long-lived plants.
“We want to create an agricultural system to feed humanity that uses nature as the measure of success.”
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Before people started intensively farming here, Kansas boasted some of the richest soils on Earth. In native prairies, dozens of grass species intermingled with clover, wildflowers, lichens and shrubs, their roots extending as far as 15 feet into the ground. Periodic fires sparked by lightning or set by native people helped clear debris and promote new growth. Insects, birds, prairie dogs and buffalo foraged in the vegetation, while millions of munching microbes buried carbon and other nutrients deep in the earth.
“The ecosystems that built the soils upon which we eat today, and that we have degraded, were perennial and diverse,” Stroer says. “That’s where we get those two characteristics that we’re trying to bring back into agriculture.”
Yet proponents of perennial polyculture have a problem: More than half of all calories consumed by people come from grains, and no one has ever domesticated a grain that lived beyond a year.
That challenge falls to plant biologists such as Lee DeHaan. The son of a Minnesota corn and soy grower, he’d heard family members talk about the Land Institute’s ideas with some skepticism.
“But it captivated me,” he says. “I saw it as solving food for humans, environmental problems and financial security for farmers.”
He began experimenting with a wild grain known as Thinopyrum intermedium, or intermediate wheatgrass. Originally from the steppes of Europe and Asia, it had been brought to North America as forage for cattle, but scientists had a hunch it could also feed people.
In the early 2000s, Land Institute scientists planted their first plots of intermediate wheatgrass. When the plants matured, DeHaan and his colleagues selected the 1,000 top specimens to replant. And when those plants matured, they chose the best among them for further breeding. It was the same process that farmers have been using to domesticate crops for millennia.
To the scientists’ surprise, those early harvests were wildly successful. The new batch of plants had stronger stalks and bigger seeds that didn’t fall out of their husks before they could be harvested.
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“We started to realize we were not that far away from something farmers could actually use,” DeHaan says.
“But the original domestication of crops took hundreds and thousands of years,” he adds. “And with climate change, we don’t have that much time.”
So he turned to tools that were unavailable to his ancient predecessors: gene sequencing, artificial intelligence and advanced supercomputers. Once DeHaan identified the genetic markers associated with the traits he was looking for, he didn’t need to wait for the plants to fully mature before picking the best ones to breed.
After two decades and 11 cycles of this process, the Land Institute has domesticated a form of wheatgrass whose seeds are two to three times bigger than those of its wild ancestor. Under ideal conditions, it can provide as much as 30 percent of the yield of traditional wheat. They call their trademarked creation Kernza — an amalgamation of “kernel” and “Kansas.”
But the plant’s best qualities are below ground. DeHaan shows me a photograph of Kernza’s roots hanging in a Land Institute stairwell — the life-size image is so long, it takes up two stories. In the first four years after planting, Land Institute research suggests, a one-acre plot of Kernza will pull roughly 6.5 tons of carbon dioxide out of the air and into those deep roots.
Kernza can’t completely replace regular wheat — at least, not yet. As Jenny kneads our bread dough, she explains that the weaker gluten proteins in Kernza flour make it harder for loaves to hold their shape. And because Kernza grains are so small, the flour also has proportionally more bran, the hard outer coating of a grain. This isn’t necessarily a bad thing — bran is full of fiber, protein and other nutrients. But it’s not exactly ideal for making angel food cake.
Still, mixed with an equal amount of whole-wheat bread flour, it’s shaping up to make a good-looking loaf. Jenny places the dough inside a cast-iron cooking pot, which will help the bread bake evenly, and slides it into the hot, waiting oven.
Before those grains arrived in my kitchen, they were grown by someone like Brandon Kaufman, a fourth-generation Kansas farmer. Kaufman is one of the co-founders of Sustain-a-Grain, a coalition of growers and buyers working to turn the Land Institute’s vision of perennial polyculture into a marketable reality.
That means more than just planting Kernza. Farmers must also figure out how to cultivate it alongside other species, creating fields that are diverse as well as deep-rooted.
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I visit Kaufman on a sparkling summer morning, driving past endless rows of corn, soy and wheat that blanket central Kansas. The orderly fields belie the tumult facing many small farmers. Net cash income for farms in McPherson County, where Kaufman lives, fell by half between 2012 and 2017, according to the U.S. Department of Agriculture. Buying seeds, fertilizer and equipment can put farmers in the red before a single grain is harvested, and natural disasters — which are growing worse because of climate change — can wipe out a whole year’s work in a single day. The combined debt of all U.S. farmers totals more than $400 billion.
Compared with more-traditional farms, Kaufman’s plots look somewhat scruffy. Tufts of chicory, alfalfa and clover are interspersed with the tall stands of Kernza. Ladybugs dot the greenery, and songbirds twitter in the brush. Kaufman leans down to turn over a dried clump of dung — an offering from the cattle he brings to graze here twice a year. Wriggling in the exposed dirt are several soil-enriching earthworms.
Kaufman’s neighbors would call his fields “dirty.” The mix of crops makes them harder to harvest by machine and less profitable per square foot. His own father, who gave him this land, is skeptical of the whole experiment.
Yet Kaufman says perennial polyculture has been profitable for him. He points out the rich, dark green color of Kernza growing beside patches of alfalfa — a product of the latter plant’s ability to fix nitrogen in the soil. When he brings his cattle to eat the alfalfa, they will spread their waste across the fields and trammel old vegetation into the earth. All this means Kaufman doesn’t have to buy synthetic fertilizers or spend time hauling manure. The ladybugs and birds feed on crop pests, reducing the need for pesticides.
“I don’t need all these inputs and overhead,” Kaufman says. “Diversity is my crop insurance.”
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That’s not to say it’s easy. Kaufman is in a constant battle with weeds, which flourish in his herbicide-free fields. Farm equipment isn’t designed to handle Kernza’s small grains, so harvesting and processing are less efficient. There are scores of kinks to work out in the supply chain connecting farmers to consumers.
But Kaufman thinks about the land he inherited, depleted by a century of intensive farming. He thinks about the state of the planet, battered by climate change and species loss and habitat destruction.
And he thinks about his four children, who he hopes will someday earn their livings from this earth. If his experiments with Kernza are successful, he’ll be able to leave them not just a healthier farm but a healthier world.
“Talk about a legacy,” he says.
Two decades after the Land Institute planted its first field of intermediate wheatgrass, Kernza can be found in the ingredient lists of cereals, baked goods and beers. For now, most of the products are pricey — the flour that Jenny and I are baking with costs more than $11 per pound, for example, compared with less than $1 per pound for regular all-purpose flour.
Meanwhile, DeHaan and colleagues around the world are working on perennializing other crops: soybeans, sorghum, sunflowers for oil. A form of perennial rice developed at Yunnan University in China has been in commercial production since 2018.
“There’s a lot more belief we can achieve what once seemed unachievable,” DeHaan said.
The proof will be in the eating. Jenny pulls our loaf from the oven, filling the kitchen with a tantalizing, yeasty smell.
“I’m excited that there’s movement in the idea of more sustainable agriculture,” she says. “I hope this can prove there’s a market.”
Finally the bread is cool enough to cut into. Jenny takes a bite, tilts her head and chews. “It tastes like —” she trails off, then tries again.
“Texturally, it’s like rye, but a little spongier,” she says. “And it’s almost like it’s got a hint of herby or spicy-ness.”
She grins. “It’s delicious.”
And we both grab another slice.