40 Chances

by Howard G. Buffett

  Worms are powerful allies in the Brown Revolution. Here a Mexican farmer shows me soil he was improving with a revolving worm bank, a program we funded to help farmers become “soil nutritionists.” It’s a simple, low-tech approach that can improve soil quality almost everywhere. Photo: Howard G. Buffett

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  I. HWB uses different techniques on our Nebraska farm than I use on my fields in Illinois. I have fields whose soils have roughly 2 percent organic matter, while others nearby have 4 percent—that means I need to use different amounts of fertilizer on each. Other variables include slope, drainage, soil compaction, pH levels, and available nutrients.

  Story 21

  For Yields to Go Up, We Have to Look Down

  As I thumbed the machete blade with a flourish, I felt like one of those stage magicians who invites his smiling assistant into a box and then pretends to slice her into three pieces.

  I was on a field visit in the Nampula Province of Mozambique. We were with a group from the international relief and development organization CARE, taking a tour of the Mogovolas District, where local farmers utilized what is arguably the simplest technology to improve soil quality available to many farmers in Africa. It’s sometimes called a zai hole, or planting basin. There are different variations, but these farmers were using individual basin-shaped holes about two feet across with sloping sides. Someone in our group who was not a farmer asked what could possibly be so helpful about digging a hole in this field of otherwise rock-hard dirt.

  I asked if anyone had a machete. A young farmer watching us grabbed one and handed it to me. I checked the blade and placed the tip in the hardpan (compacted, almost cement-like soil) between two basins. I pushed. Nothing happened. I put both hands on the machete handle and leaned all my weight on it. It penetrated maybe a half inch. Then I took two steps and put the tip a couple of inches from the base of a maize plant growing in the middle of the basin. I took two fingers and placed them on the top end of the machete. It slid easily into the earth all the way to the handle.

  A subsistence farmer in Mozambique uses a zai pit to improve poor soil conditions. Zai pits work best where there is an abundance of labor and the opportunity to collect large amounts of organic material. Photo: Howard G. Buffett

  I’m no magician, but these planting basins really do perform a little bit of magic: they turn dirt into soil.

  Most of us take for granted the ground on which we walk. We even use expressions such as “dirt cheap” or “treating him like dirt” to suggest contempt and disrespect. Dirt is just the accumulation of what’s on the ground. Dirt is the equivalent of inert Play-Doh that we push around to create a base or foundation for other things we consider much more valuable: buildings, roads, canals, tunnels, walls.

  Soil, on the other hand, is a treasure. It is any farmer’s most valuable working capital. Soil fertility has the single largest impact on production capacity.

  The difference between dirt and soil is that soil is alive: home to millions of diverse microbial organisms. The best soil for planting is soft and crumbly loam—a combination of sand, silt, and clay—and its surface is rich in organic matter, including decayed plant material and nutrients. The best soil has structural integrity, or tilth: neither so sticky with clay that roots can’t penetrate it, nor so sandy that it can’t hold nutrients and moisture. It is full of minerals that work their way up from the bedrock below. (Credit earthworms with a big assist.) Soil, like any biological system, is complicated. On just one of my fields in Illinois, there are four different class I (the best for agriculture) soil types of the A and B hydrologic groups: Flanagan, Catlin, Wingate, and Elburn silt loams. The hydrologic groups separate soil types by how water tends to infiltrate. To maximize productivity, I use a different seeding rate, or number of seeds planted per acre, for each soil type.

  The soil in those Mozambique basins was no Flanagan silt loam. But in comparison to the surrounding rock-hard dirt, its looser structure and higher organic content were a huge improvement. After digging the pits, these farmers put in manure mixed with earth and plant seeds on top of that. That attracts termites, which dig tunnels in the soil, transporting nutrients from deeper layers to the top and aerating the mixture. Because of the bowl design, the basins collect and concentrate water around the plant roots, and they also trap blowing sand and other plant debris. The farmers also collect banana peels, peanut shell mulch, and other organic matter to keep “feeding” the organisms that decompose the material and improve the texture of the soil. It’s like a mini–compost heap, and the practice increases yields, particularly during periods when water is scarce. Finally, the farmers plant legumes or nitrogen-fixing trees between the basins. The approach is used widely in dry West African countries such as Mali and Burkina Faso, where farmers have refined the technique and started teaching it to others working in difficult soil conditions. It has been spreading east to countries such as Kenya as well.

  Basins are not the answer to feeding Africa. They can be labor intensive and need tending. But they are a clever, practical approach that requires no expensive tools or inputs. Locals told me that in the test plots in Mozambique, maize yields had tripled. The concept is a way to focus smallholder farmers’ attention (and that of donors and government officials as well!) on soil quality.

  SOIL AS A TOOL

  Soil is the most important tool we have to feed a fast-growing world in coming decades, and I am referring to all soils everywhere. To meet the demands of the world’s population growing from seven billion to nine billion by 2050, all farmers, large and small, must maximize their productivity in a sustainable way. It’s not optional. While I sometimes feel a little lonely as such an outspoken advocate about global soil issues, I am far from alone. Jeremy Grantham, cofounder and chief investment strategist of Grantham, Mayo, Van Otterloo & Co., manages one of the world’s largest investment funds, with assets in excess of $100 billion. He has said that soil degradation is one of the greatest threats facing humanity today.1 In 2008 the FAO reported that land degradation is increasing in severity and extent in many parts of the world, with more than 20 percent of all cultivated areas, 30 percent of forests, and 10 percent of grasslands undergoing degradation. Further, the FAO estimated that 1.5 billion people—today a fifth of the world’s population—depend directly on land that is being degraded.2

  The challenge is clear: we have to conserve and improve the soil we have, and we need to turn dirt into soil wherever people need to grow food. That’s true in America’s breadbasket, it’s true in the tropics, and it’s true in the dry, hardscrabble, weathered soils that cover much of sub-Saharan Africa.

  In the larger context of battling hunger, valuing soil belongs in the “hard lessons learned” category. This is in part because the importance of taking care of the soil growing our food seems to be a lesson that human beings have to keep learning. I’m not sure why. What many people throughout history have assumed is our most abundant resource is actually a thin skin. It takes five hundred or more years for an inch of soil to form when bedrock crumbles and earthworms and microorganisms refine it into black loam and transport it to the surface.

  And yet entire civilizations have died out or had to pick up and move because they destroyed or depleted their soils through over-farming, deforestation, and other practices that waste topsoil much faster than it forms. The Mayans, the Aztecs, the Vikings, and the Easter Islanders all devastated their agricultural productivity by failing to protect and nourish their soils. One of the earth’s current flashpoints for what I call agronomic bankruptcy is Ethiopia. Like those in much of Africa, Ethiopia’s soils are considered “old” and weathered, yet the population has tripled in the last fifty years. As a result, on top of an infertile base, farmers have deforested and overgrazed cropland, depleting productivity. Soil acidity, salinity, and drainage problems—as well as the inherently low availability of the essential plant nutrient phosphorus—mean that large areas of its soils are literally dead, devoid of biological a
ctivity. They have reverted to dirt. Tossing fertilizer on dead soils would be about as productive as putting an oxygen mask on a cadaver.

  The United States is blessed with some of the richest farmland on Earth, but we too have abused it. In the 1930s on the Great Plains, US farmers ripped away drought-hardy prairie grasses to make way for their crops. When dry weather killed the crops, there was nothing to hold down the soil against the wind. US politicians began to wake up to the danger when dust storms deposited dirt from the Great Plains on roofs in Washington, DC.

  One of the most disheartening sights I confront in winter as I drive around my fields in central Illinois are the small hills on some of my neighbors’ farms that lie fallow during the cold months. Their level fields’ topsoil is almost black and several feet deep. But these neighbors are old school. They still finish off a harvest season by disking and chisel plowing: turning over that year’s upper layer of soil, burying that year’s crop stubble. They think this aerates the soil, helps it hold moisture better, and brings nutrients to the surface. As you drive around, their fields look clean and neat: just acres of empty earth.

  But those small hills tell a different story. Invariably, the color of the soil is lighter at the top of the hills than it is on the flat land below. That’s because tilling land on a slope causes topsoil to wash downward as soon as the rains come. There is nothing to hold it in place. And plowed flat lands also lose soil to blowing winds or to runoff when the fields flood from rains or snowmelt. According to one study, one hundred years after Iowa was settled, half the state’s topsoil was lost.3

  In contrast, I practice what is called conservation farming. Next to plowed fields, mine are downright messy looking. I don’t remove the stalks of corn or wheat stubble after I harvest. I even plant annual rye or radishes and other noncrop plant species in between the harvested rows of corn. All winter, as the rains come and the snow builds up, those so-called cover crops help me hang on to my topsoil. And in some cases, they help my soil retain, or “fix,” nitrogen so that I can apply less fertilizer for the next crop I grow. In the spring, when it’s time to plant, I put seeds directly into the soil, never disturbing the dirt other than a thin strip where the planter opens up a slot to drop in the seed.

  No-till farming systems always maintain cover on the soil. By planting directly into the previous crop residue or cover crops, this process builds healthy soil, sequesters carbon, reduces soil erosion, and cuts the use of fossil fuels. Photo: Howard W. Buffett

  This approach falls under the category of “no-till” farming techniques. It’s about an entire system of farming that uses cover crops, minimal till techniques, better nutrient management, and crop rotations. This is not “organic” farming. I do use genetically modified seeds that resist pests and are able to tolerate herbicides such as Roundup, and I do use nitrogen-based fertilizer. While I am convinced that soil-focused techniques are essential to our future, I don’t believe that organic methods can produce the yields our planet needs to feed us all. And so I have settled on an approach that I feel is practical but also sustainable. I’m sorry to say that the United States has been slower to adopt conservation farming than countries such as Argentina and Brazil, where yields are just as good using these more soil-protective techniques.

  Argentina’s and Brazil’s tropical climates create a unique issue for their soils: the warm, moist climate means organic matter decomposes faster. When farmers in the tropics slash and burn rain forest to try to plant food crops, as they did for many years, they get a few years of production at best before they deplete the soil of nutrients. Once that happens and they move on, they leave an ugly scar of empty ground behind them—ground that once nourished plants that contributed to the planet in many other ways, from housing animal and plant species, to producing oxygen, to sequestering carbon. In recent years, these countries have adopted much better soil nourishment and management techniques, and their farmers have experienced significant productivity gains in the process.

  Farmers in many parts of Africa also practice a form of slash and burn. They find space on their tribal land for growing crops by using a machete to clear away the bush so that sunlight can reach through to the ground. After the harvest is gathered, the leftover stalks and leaves are burned to clear the field for another planting season. After two or three years, the exposed soil is so exhausted that yields plummet. Traditionally, farmers would then move on to hack out another plot and leave the depleted ground alone for several years so that it could recuperate. One of the problems in a place such as Malawi is that the population density is so high and the land available for agriculture so limited that fields cannot be left fallow to rejuvenate.

  Farmers in Africa clear land for agriculture by cutting and burning brush, wasting valuable material that could build soil health. Photo: Howard G. Buffett

  EVEN A POOR FARMER CAN MAKE SOIL RICHER

  The first time I really understood the impact of slash-and-burn fields in Africa was from a rickety airplane as I photographed zebras and wildebeest migrating across the plains of the Masai Mara National Reserve near Kenya’s border with Tanzania. After the shoot, the pilot said he wanted to show me something. His plane circled higher and higher to gain enough altitude to get over a towering escarpment. On top of it sat a forest. The pilot pointed down to where farmers were burning down trees to make room to grow corn. Local people were encroaching on the forest because they needed fertile soil. Later I learned that the rate of deforestation is often highest in the world’s hungriest countries, which continues today. Togo and Nigeria had the highest rates of deforestation out of sixty-five nations, according to a 2011 study of deforestation rates between 2005 and 2010. Togo lost an average of 5.75 percent of its forests annually, and Nigeria posted a 4 percent rate.4

  Much of sub-Saharan Africa’s struggles are due to its having the most weathered and degraded soils in the world. Africa is an ancient plateau and the continent is worn out geologically. And as we’ve discussed, much of Africa lies outside the fertility belt of climate and ideal soils hardwired to produce the cereal grains that feed the world. Only a small portion of Africa’s soils are fertile to start with, but then slash-and-burn techniques degrade those even more.

  At our foundation’s Ukulima facility in the Limpopo region of South Africa, the best ground has just a few inches of topsoil, if that. We have a number of projects underway that focus on soils. But one of them, spearheaded by scientists from the Florida-based nonprofit Educational Concerns for Hunger Organization (ECHO), features a series of over five thousand zai basins. ECHO is trying to determine how to coax even more productivity out of this technique.

  “This soil is like beach sand. The water just goes right through it,” says ECHO scientist Brandon Lingbeek, toeing the dry ground. He explains that he and his research partner have been planting legumes such as cowpeas, pigeon peas, and lablab in between the zai holes planted with sorghum, a grain grown widely throughout Africa, as it’s more drought tolerant than corn. The technique is called intercropping, and they hope not only that it will add more nutrients and organic matter to the soil, but also that the legumes themselves can be consumed by both people and animals. “The baseline nutrients in this soil are next to none. Weeds produce biomass, but they don’t improve the nutrients of the soil the way legumes do. It’s sort of ‘grow your own fertilizer,’ ” Brandon says, laughing. “We’re trying to not only find cheap options for poor farmers, but options that are sustainable. What sets our research apart is it starts with what these farmers are already working with.”

  A fence that runs along the zai pit plots demonstrates another challenge to these difficult farming conditions. One section has been reinforced with steel rebar rods and big rocks piled up against the base. Local porcupines love the legumes and wage a relentless assault at night. At one point, the guys pitched a tent and set up floodlights to try to scare them off. “As fast as we fix it,” explains ECHO’s Chris D’Aiuto, “they tunnel through.”

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p; This work could have important consequences for farmers coping with depleted and damaged soil, particularly in semiarid and arid regions of Africa such as the Sahel, where desertification has become a major issue. The effects of increasing droughts and the removal of trees from the landscape are exposing the soil to erosion and to the harsh rays of the sun, which creates barren, encrusted soils. When it does rain on these soils, the water washes away instead of percolating down.

  Also at Ukulima, we’re supporting researchers from Pennsylvania State University who are looking at root architecture. Some plants have deep root systems that are good at finding water in the subsoil, making them more drought resistant. Others have shallow root systems that allow them to take up nutrients such as phosphorous and nitrogen more efficiently in the topsoil. The Penn State team is trying to breed varieties of corn and other crops that combine these architectures to give smallholder farmers seeds that can improve their yields in the stressed conditions they face, where both water and fertility are low.

  We need to focus on Africa’s poor soils to get at the root of Africa’s agricultural challenges. Soil is something that the poorest farmer in Africa can make richer, as these conservation techniques show. And if Africa’s leaders need to be convinced that a Brown Revolution can lift up a country, they can find an excellent example in Brazil, as you’ll discover in part 5.