Roots of Ages
Originally published in the November 2012 issue of Empirical
In the beginning, there was no soil. But there was rock.
And weathering and gravity made the rock into particles, and bacteria, plants, worms, and legged things pitched in to make soil. And it was good enough to farm. But, lo, the crops that raised civilizations were annuals.
Soil-building vegetation was mostly perennials. And after harvest of annuals the soil was naked, and it blew and washed away. And what was left was not so good to farm. Farmers brought the soil gifts of legumes and manure, and eventually of anhydrous ammonia. This fed the grains that fed civilized humanity. The new fertilizer fed it so well that humanity owed near half of its life to a product of burning fuels that took even longer to form than soil. But the grains remained annuals.
And the soil still blew and washed away, and farmers moved to lesser and even more vulnerable land. Some in science saw humanity headed downstream with the soil. And a few finally asked, “Can’t farming work more like the natural vegetation that forms soil, but still feed us?” And they studied and decided it could.
And they began breeding plants to achieve perennial grains, and testing how these might grow in species mixtures, like prairie. They knew this would take much longer than six days or even six years. But after much fundraising and educating and painstaking field and lab work, they coaxed more and bigger seed from perennial plants once wild, and they bred tame annual plants to behave more like perennials. And they saw this could be really good.
There is the first chapter in what could be called a genesis of natural systems agriculture. Or, of synthesizing evolutionary biology, ecology, modern genetics, and farming. The work that I have tried to sketch in a fun way has become a serious endeavor, if still marginally funded, at several organizations around the world, including in Australia, China, Canada, and the United States.
The oldest current player–though the Soviets tried first, only without modern genetic know-how–and the central player is The Land Institute, near Salina, Kansas, which has six PhD-level researchers plus technicians developing perennial wheat, sorghum, and sunflower, and domesticating the perennial intermediate wheatgrass and a protein-rich, nitrogen-fixing prairie legume called Illinois bundleflower. Wheatgrass, for which the institute has a trade name, Kernza, might be a commercially viable grain in another decade.
The nonprofit has through the recession continued to increase its budget, to $2.3 million, and collaborates with the researchers elsewhere. Its wheatgrass and other crops will essentially be public domain. These plants won’t require farmers to buy and plant seed every year. With less tillage, they will take less money for fuel and machinery.
And in working more like a natural system, mixtures of perennials should need less of the other high farm expenses, fertilizer and pesticide. About half of The Land Institute’s funding comes from foundations, half from individuals, and a sliver from the USDA. These crops do not yet interest agriculture corporations.
Wes Jackson, who grew up on a farm near Topeka, Kansas, and earned a doctorate in genetics before he quit a tenured university position and founded the institute in 1976 at age 40, recently has pushed for investment much bigger and broader.
He examines the danger of population growing while farmland degrades and the crutch of fossil fuel declines. He studies the advances over the past decade by his researchers and others toward a solution in perennial grains. And he sees convergence for a decisive, historic moment. Two years ago he, along with farmer/writers Fred Kirschenmann and Wendell Berry, proposed a 50-year federal farm bill, to look far beyond the traditional five-year bills and solidly support work that will take decades.
Now the institute proposes a 30-year effort enlisting more than 160 scientists on five continents. The $1.64 billion cost divided over the years would be 24 times the institute’s own current spending. But in total it would cover four months of the old federal ethanol subsidies.
Another comparison: the three-decade proposal is less than one tenth of the $18.7 billion annual budget for NASA. Jackson has said we are of a culture that keeps looking to the stars, thinking it beneath us to look at the soil. We don’t appreciate the material that supports all of our dreams, and the biological creativity without which we cannot be, let alone be scientists and artists. Jack Eddy wrote in an essay called “A Fragile Seam of Dark Blue Light,” Earth is where “a thin blanket of air, a thinner film of water, and the thinnest veneer of soil combine to support a web of life of wondrous diversity in continuous change.”
Change to that thinnest veneer since humans became farmers 10,000 years ago, and a change accelerating with increase of population and machinery, includes growing even thinner. In “Earth,” geologists Edward Tarbuck and Frederick Lutgens say erosion is a fate of almost all soils. But pre-human flow of sediment to the sea is estimated at just over nine billion metric tons per year, they say, and now the loss is about 24 billion. Gauging wind erosion is harder. But in the 1930s Dust Bowl, a perfect bomb of drought and farming, the Plains’ rich soil palled Washington’s sky en route to Atlantic grave. To build an inch of soil takes from half a decade to more than a millennium. Global averages have been calculated at 150 to 450 years.
Meanwhile, Australian scientist Joe A. Friend writes in an essay called “Achieving Soil Sustainability,” in many parts of the world an inch of soil disappears every one to 10 years. He says that a majority of world soils are being mined faster than they can be regenerated.
Tarbuck and Lutgens see this net loss on more than a third of world croplands. Friend says of soils, “They are intrinsically nonrenewable and may become completely unusable within a few generations.”
Agricultural civilization’s band of instigators 400 generations ago didn’t foresee this. And when they perceived an advantage to planting seeds, they favored those of annuals. As Land Institute scientists and John P. Reganold of Washington-State University detail in Scientific American, the earliest domesticates, emmer-wheat and barley, caught the Neolithic eye with large seeds. Further favor came to individual plants with traits such as high yield and easy threshing–it was their seed that people replanted. Replanting with annuals comes every year. So the first farmers unwittingly applied evolutionary selective pressure to quickly domesticate these choice annuals. Some perennial plants might also have big seeds. But they did not need to be replanted. Through no real fault of their own, they did not benefit from the same selection and fast improvement.
Now most of our food comes directly or indirectly, as animal feed, from cereal grains, legumes, and oilseed crops, all of them annuals. Wheat, rice, corn, soybean, and sunflower seed transport and store easily, and pack protein and calories. They occupy about 80 percent of agricultural land.
But annuals have relatively shallow roots, most of them in the top foot of soil, and live only until harvest. Perennial roots commonly tunnel down more than six feet. Unlike annuals, perennials must invest in building enough underground tissue to survive the winter. But that tissue can improve the ability of annual seed to spring into above-ground growth by weeks. Photosynthesis earlier and after harvest lets perennials build both seed and resilient infrastructure.
In a century-long study of soil erosion, timothy grass, a perennial hay crop, proved more than 50 times more effective in maintaining topsoil than did annual crops. Scientists have documented a five-fold reduction in water loss and a 35-fold reduction in nitrate loss from soil planted with alfalfa and mixed perennial grasses as compared with soil under corn and soybeans. Perennials sequester carbon, the main ingredient of soil organic matter, by 50 percent or more than do annually cropped fields.
Jackson saw that Kansas’s tall-grass prairies were highly productive year after year even while they built and maintained rich soils, with no fertilizers, pesticides, or herbicides, and with what rain they relinquished running clear instead of muddy.
He foresaw agriculture working this way, with both conservation of the system and production for our food.
This change is radical–going to the root–and trying to achieve perennial grains has had critics. They say that to match the seed yield of annual grains, perennials would have to give up the carbon that makes winter-hardy underground tissue. That assumes that the amount of carbon available to a plant is fixed, so what goes to making seeds comes at the expense of structures like roots. But plants are flexible. They can change both the total size of their carbon “pies” and how the pie slices are allocated. A wild perennial in its highly competitive prairie or forest might make only small amounts of seed. But farming’s law and order relieves plants from competition.
The same seed can become a bigger plant. And over years breeders can select for plants that produce less of something like competitive stem height, and redirect the carbon to make more seed. Thus Green Revolution scientists dwarfed plants and doubled grain yields. (They also used more fertilizer.) Perennials have a longer growing season than annuals and already can make more above-ground growth. In a University of Illinois side-by-side study, unfertilized, perennial Miscanthus outproduced fertilized corn by half again, with one-fourth the energy input. Land Institute researcher Lee DeHaan has doubled wheatgrass seed size and yield and not made winter weaklings.
Achieving perennial grains demands much human work and will take decades. But perennials have shown their potential. Like other agricultural scientists, the developers of perennial crops both directly domesticate wild plants, selecting the best from within one species, and breed annual crop plants with wild relatives. In direct domestication researchers get straight to increasing the frequency of genes for desirable traits, such as easy separation of seed from husk, seed that doesn’t fall before harvest, large seed, taste, strong stems, and high seed yield. In this way, Native Americans turned wild sunflowers with small heads and seeds into the familiar large-headed and large-seeded sunflower.
Land Institute scientists are domesticating intermediate wheatgrass, Maximilian sunflower, and Illinois bundleflower. Recently joining in the work with wheatgrass is the University of Minnesota. On the hybridization track, The Land Institute breeds annual crop wheat, sunflower, and sorghum to wild relatives, aiming to combine good crop traits with perenniality, along with perennials’ resistance to pests and disease. Washington State also works on perennial wheat, and researchers at three other US institutions are interested in making corn perennial. Food Crops Research Institute in Kunming, China, is developing perennial upland rice hybrids.
Of the 13 most widely grown grain and oilseed crops, 10 are capable of hybridization with perennial relatives, Land Institute researcher Stan Cox said. This all has come through traditional plant breeding, without insertion of foreign DNA. No solitary gene can switch a plant to perennial.
Cross-fertilizing plants of different species, often of different genus, is tricky genetic business, with many sterile failures. But through lab work and crossing back to fertile parents comes success. Triticale, a hybrid of wheat and rye, was born this way a few decades ago. Cox now has hundreds of perennial sorghum plants.
So here is a possible second chapter to the story of nature and agriculture.
Just as they learned to save eagles and redwoods, people came to champion soil, so lowly for so long, but so vast, rich, and mysterious, and often so fragile, its loss the loss of Greece, Carthage, and Rome, its continued endangerment also endangerment of those eagles, redwoods, and people.
They learned to see how in the natural economy perennials build principal. They saw how other life made do, wildly, on interest, and how the great plow-up that was farming spent down the principal. They saw this through art and science bought with those riches. And through that science and art, they saw a way to preservation. And in the end, there was soil.
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