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CHAPTER 1
WHERE DID ALL THE CARBON GO?
Plot 87 of the Waterman Agricultural and Natural Resources Laboratory at Ohio State University used to be part of a farm. Pioneers chopped it out of the dense central Ohio forest in the 1800s. They raised corn, wheat, and oats for the horses; rye for making whiskey; flax, which they mixed with wool to make linsey-woolsey clothes for the men; apples, perhaps even a variety carried to Ohio by John "Johnny Appleseed" Chapman; and probably a dozen more crops. It was enough to feed themselves amply from the rich soil below, have some to share with neighbors, even sell to the occasional stranger. They picked arrowheads and stone beads from the soil, wondering about the ancient native peoples who had also flourished in the valley's great fecundity.
The Watermans were the last to plow this land, and when the city and suburbs of Columbus closed in on their farm they decided to give it up to the university. Now only a few dozen acres remain, encircled by swaths of forest, which are in turn surrounded by the new urban canyons. Two unlike groups of moving objects, the nearby traffic and the hundreds of birds that swoop and survey the fields, make a cacophonous backdrop.
These acres have been preserved from the bulldozers so that a handful of soil scientists can pursue experiments. On a cold, wet morning of a spring that had been cold and wet for weeks, Rattan Lal drove me there to see what, if anything, was growing. He was afraid that it would be too early for their test crops to have popped the sodden crust of soil.
But as he stepped from the university truck and navigated the puddles on the dirt road, he smiled and pointed. "There is something growing!" In Plot 87, rows of new corn--like wavering lines of tiny green feathers--stretched toward the blocky city skyline.
Lal is the director of the university's Carbon Management and Sequestration Center (C-MASC), which attracts researchers from around the world. The experiments surrounding us were those of his students. He has been at this work for 50 years. A tall, graceful man with white hair and large gray- rimmed glasses, he doesn't dig in the dirt anymore.
Even so, whoever planted this particular field relied on two of the methods for enriching the soil and preventing erosion that Lal came to appreciate early in his career and has preached the use of for years. No-till agriculture, for one. I grew up in an agricultural valley in California and love the rhythm of plowing, the graceful lines incised on the land, the opening up of all that bountiful and mysterious earth. I especially love it in Ohio, which was still my home when I visited Lal in 2012, where you can drive down back roads and see Amish farmers plowing with their teams of giant, furry-hoofed horses. But plowing actually damages the soil structure and exposes soil carbon--the crumbly blackness that generations of farmers have recognized as a feature of the best, richest soil--to the air, where it combines with oxygen and floats away as carbon dioxide. So this field was planted using a machine that punched slits in the soil through the roots and debris of last year's crop and dropped in seeds. It was a field without furrows.
The second difference: While the thousands of acres I passed on my way down from Cleveland rolled along the sides of the road like bolts of neat brown corduroy, Plot 87 was littered with bits of dry leaves and cornstalks. Instead of burning the residue from last year's crop or letting someone haul it away for their pigs or sending it off to an ethanol plant that previous fall, the residue had been chopped up and spread over the land. Left there on the ground, the residue reduced erosion. It kept the soil temperature cooler during the summer. It provided food for worms and other creatures that aerate and enrich the soil, and thus help make it more porous and absorbent.
Lal leaned down and tapped a long, slender finger on a layer of half-rotted corn stalks, the swirling om tattoo on the top of his hand a faint blue in the weak sun. He pushed the crop residue aside to examine the soil. "See how the ground underneath has no cracks?" he said. "When it's covered, the residue protects it from the hot sun and it doesn't dry out so much. And here"--he poked his finger into a loose mound of soil--"here, you see where organisms have been eating the residue. This is their waste product, which makes the soil richer and loosens the soil. An earthworm can drag a leaf down more than three feet into the soil."
His gaze switched from the micro to the macro. "When you look across the field, you see that there is no water on the surface," he said. "This soil absorbs moisture. The water doesn't run off or make puddles."
I recalled seeing the pools of water from last night's rain on the fields along the highway on my drive south. This field was like a huge brown sponge, with all that water lying beneath our gaze, suspended in the land's pores.
It was what I couldn't see that had drawn me to meet with Lal, and that was the carbon content of the soil. Lal became a soil scientist mindful of the world's poorest farmers--he grew up among them, first on the Pakistan side of Punjab and then, after partition, on the Indian side--thinking only of helping them raise better crops and save their soil from washing away. Along the way, he realized that when the soil lost its life-giving carbon through plowing and poor land management, its disappearance into the air wasn't just a blow to the millions of poor farmers or an inconvenience to the thousands of corporate farmers in the developed world, it was adding substantially to the threat overhanging the entire planet: the load of greenhouse gases in the atmosphere. In fact, up until the 1950s most of the excess carbon dioxide in the air resulted from the ways humans used their land and forests.
So even though he doesn't dig in the dirt anymore, Lal stays busy. He spends much of his time traveling to conferences around the world, talking about the connection between soil carbon and global warming. The message: We need to do everything we can to stop losing historic soil carbon, and we also need to do everything we can to build and retain more carbon in the soil. He also takes this message to the National Climate Assessment and Development Advisory Committee (NCADAC), where he is the only soil scientist. Other soil scientists know about the connection between soil carbon and global warming, but they have not been aggressive about taking this message outside their field or explaining the importance of their work.
"Even I am bad about this," said Lal, who was the president of the Soil Science Society of America (SSSA) in the early 1990s. He grinned. "The other day I was explaining something to a group and I said, 'It isn't rocket science.' I thought about this later. I should have said instead that 'It isn't soil science'!"
Even though Plot 87 is a far cry from his family's 2-acre farm in India, it brings back memories. How his father plowed the fields with a team of bullocks, and then he and his father leveled the fields by sitting on a board, which the bullocks dragged over the ground. How they separated out the wheat seeds by drying the wheat in the sun and then nudging the bullocks to drag it over the ground. How they cleaned the seeds by throwing them up in the air and letting the wind whisk away the dirt and chaff.
They lived in a village of mud-brick houses, with no electricity or even roads. All the men wore beards because no one owned razors and there wasn't a nearby barber. One came to town monthly and trimmed hair and beards in exchange for a share of the wheat and rice crops. Every family had a cow for milk, which they converted to yogurt, a staple of their diet. When a cow died--all good Hindus, they'd never think of killing one for its meat-- the butcher arrived to convert the hide into shoes. "They were so stiff and painful for the first few days!" Lal said. "We always got blisters. Sometimes we just carried the shoes around in our hands."
They had enough to eat on the farm, just barely, but starvation was rampant in the cities. Farmers just didn't produce enough to feed the population. Looking back with a scientist's eye, Lal sees that low, dwindling productivity was inherent in their centuries-old methods. It was not only the plowing that was a problem. The greater concern was that the villagers took from the land and never gave anything back--something he now calls "extractive farming." They gathered crop residue from the fields and took it away to burn in their stoves or to sell at the market. They gathered the bullocks' dung, dried it, and burned that, too. Leaving both in the fields would have enriched the soil but further impoverished the farmers. "The residue and the dung were precious, and we carried them away," Lal says. "No one leaves them on the ground there, even now. They're still precious to a poor farmer."
When he was 7 years old, a peddler bicycled through the village offering tattoos for two pennies. Lal doesn't remember where he got the two pennies, but he had the peddler tattoo his hand with the symbol for om, a Sanskrit word meaning the sound of creation. As he looked at the small black welt, he felt that this wasn't enough for the mighty sum of two pennies. The peddler obliged him by tattooing his initials--RL for "Rattan Lal"--on his upper arm. The boy couldn't read English, so the letters meant nothing to him.
But he knew om. His grandfather was a Hindu priest, and the boy knew 40 yoga poses and how to recite the mantras that went with them. The family intended him to follow his grandfather into the priesthood, but the youthful Lal knew more than his mantras--he was also good at math. Finally, the family decided to send him to university in Delhi. He was wandering the halls one day and struck up a conversation with a young man crouched next to a doorway. He was a peon--it was an actual paying job, to run someone else's lowly errands--and Lal asked him if he could help him find a job as a peon, too. Just then, a jeep emblazoned with the name OHIO STATE UNIVERSITY pulled up outside the building. "Americans are here?" Lal asked.
The peon nodded. "And they give scholarships."
A few years later, Lal arrived at Ohio State on scholarship with an $8 traveling stipend from the Indian government--a sum he found lavish until he discovered that a night's housing cost more than that. He found himself a place to stay by following the sound of applause down a university corridor and peering in to see a roomful of international students. Some were wearing the turban of his native Punjab, and they invited him to stay with them until he got on his feet. After that, there were more scholarships and awards and mentors, enough to assure his brilliant future. "I am very lucky," Lal says. "The stars aligned for me."
Years passed before he tripped over the first big hurdle in his career. After he finished his PhD in soil science, he was hired by the International Institute of Tropical Agriculture in Nigeria, 1 of 15 research centers funded by the Rockefeller Foundation. There, he spent 13 years trying to develop sustainable alternatives to the kind of farming practiced by Nigerians and many other Africans.
Unlike the farmers in his Indian village who worked the same fields for years, the Africans practiced what's called "shifting" or "slash and burn" agriculture. They cleared plots in the forests with a machete, then burned the wood to provide nutrients for the soil. They raised corn, yams, and casaba on their plots until the land simply gave out. That tended to happen in just a few years, since the soil in many parts of Africa is very old and very shallow, with often just a foot of good soil above the rocky subsoil. In the parlance of agriculturalists, the rooting depth is low. After the plot was exhausted of nutrients, they'd leave it fallow for 15 or 20 years to recover. But as the population grew, they were running out of virgin forest to turn into farmland and were surrounded by old, unproductive plots. Lal's job was to help them restore fertility to the soil.
Lal began clearing areas for his test plots. His first effort was close to an utter failure. He plowed the land after completely clearing it--even pulled out tree stumps, which the local farmers didn't do--and built terraces to control water runoff. He planted maize, cowpeas, and rice, and everything seemed well. But the night before his board of directors was to view his work, 4 inches of rain fell in 2 hours. All his plots save one washed away, leaving behind gaping gullies in the soil. The one plot that survived had been heavily mulched with crop residue.
He asked his board of directors to postpone its visit, but he learned from the failure. He realized that disturbing the soil by plowing made it susceptible to erosion. Plowing also destroyed the structure of the soil-- the internal architecture of sand and silt and clay created over the decades by earthworms and other organisms that allowed air, water, and nutrients to circulate. He decided to disturb the soil as little as possible when he prepared his next plots. He cleared some land by hand, some with a machine that cut the forest at ground level, and some that killed the vegetation with chemicals, leaving the roots intact. He sowed some plots with cover crops, which are typically grown not to eat or sell but to enrich and protect the soil during fallow periods. And he mulched some crops heavily, wanting to demonstrate how the chopped-up crop residue would protect the plots from being washed away by the rain and protect the precious carbon-rich topsoil.
