The Biodiversity That People Made

The Biodiversity That People Made

Snaking along the border of Minnesota and the Dakotas, the Red River valley has long been one of North America's leading grain-producing regions. Blessed with fertile prairie soils deep enough "to bury a man standing," Red River farmers have intensified their production in recent decades, and planted more and more of their land to just two crops, wheat and barley.

Such specialization is supposed to be the key to success in the brave new world of multinational agribusiness. Yet the last few years have been anything but bountiful for most Red River farmers. In the early 1990s, following several years of abnormally cool, wet weather, their fields were hit with unprecedented outbreaks of a fungal disease called "wheat scab."

But according to Brian DeVore of the Minnesota-based Land Stewardship Project, the fungus is benefiting from more than just the weather. Many of the region's farmers have recently adopted a "no till" cultivation system that is designed to conserve soil. Standard cultivation prepares the soil for planting by plowing, but as the soil is broken up it becomes vulnerable to erosion. "No till" reduces erosion by leaving the previous year's broken stalks in place and planting through them. Unfortunately, however, those crop residues are a perfect home for the fungus in between growing seasons. A few decades ago, one solution would have been to let cattle graze down the residue, but there are few cattle in the region any more. Cattle production has grown increasingly specialized too; few of the valley's farmers can compete with the enormous livestock operations elsewhere. So the fungus has its way with these vast, monotonous expanses of wheat, one field after another, year in and year out: that must be the wheat scab version of heaven.

The bottom line is that disease and record low grain prices have cost Red River farmers over $4.2 billion since 1992. Nearly half of that loss is directly attributable to the scab. On the Minnesota side of the river, wheat and barley plantings in 1999 were down some 35 percent compared to their levels at the start of the decade. One-fifth of the region's farmers went out of business in 1997 alone.

Such problems are usually debated in economic terms, but they are related just as fundamentally to the loss of biological diversity in agriculture. Biodiversity refers to the variety inherent in life-both the genetic variety within single species and the "species variety" within ecosystems. For most people, the term probably evokes Nature with a capital "N"-tropical rain forests, coral reefs, mountain wildernesses, and other untrammeled corners of our planet. Not surprisingly, most of our efforts to protect biodiversity have focused on such places.

Yet there is another side to biodiversity, one that is very much a part of human history. As agriculture developed over the past eight millennia, farmers domesticated several hundred different crop species, and developed hundreds of thousands of different varieties within those crops. In the hands of early European farmers, for instance, an inconspicuous herb of coastal Mediterranean hillsides gradually became cabbage, kale, cauliflower, broccoli, and somewhat more recently, kohlrabi and brussels sprouts. Native American farmers took five shrub species with small, bright fruit originally adapted to attract birds, and diversified them into hundreds of eye-catching and tongue-searing varieties of chile pepper. This ancient form of "cooperation" between people and plants has produced a vast wealth of genetic diversity within crop species.

Traditional agriculture fosters diversity in another dimension too, particularly on land used, not for commercial production, but primarily for "subsistence production"-that is, land that farmers cultivate for their own households. In just about any part of the world, subsistence production results in a highly diverse agricultural landscape. You'll find intensively cropped fields for staples such as wheat, corn, rice, or potatoes; fallow fields covered in more unkempt vegetation, where the soil is "resting" to regenerate its fertility; an orchard or garden plot for fruits, vegetables, and herbs; a woodlot for fuelwood and other forest products. This kind of land use, replicated on farm after farm, creates substantial ecological diversity.

Today, both forms of agricultural biodiversity are receding in the face of commercial production, which usually demands a high degree of uniformity. The economic and political pressure on farms to grow for the mass market is a pervasive effect of the globalization of agriculture, and in many places, farmers are forsaking the practices that have long fostered biodiversity-practices that have sustained farming for millennia. But it's becoming increasingly obvious that the current agricultural paradigm will be far less sustainable. Intensive monoculture farming is exacting a heavy ecological toll in the form of pesticide and fertilizer pollution, erosion, freshwater depletion, and the destruction of wildlife habitat. And as farmers in such places as the Red River valley have found, the social costs can be very steep as well. The message from such places is now very plain: we've no hope of achieving a sustainable agricultural system unless we can find ways to restore what scientists now call "agrodiversity."

Hot Spot Agriculture

During the 1920s, a brilliant young Russian scientist named Nikolai I. Vavilov undertook to answer a question that must at the time have seemed vast in its implications if rather bizarre: what was the origin and significance of genetic variation among crop plants? Vavilov was a firm adherent to the emerging disciplines of evolutionary theory and genetics, and he approached his studies with enormous intellectual energy. From a home base in St. Petersburg at the All-Union Institute of Applied Botany and New Crops (which he headed after 1925), Vavilov organized expeditions not only to the fields and gardens of remote corners of the Soviet Union, but also to Iran, Ethiopia, Mexico, Japan, and some 50 other countries. Tens of thousands of different crop specimens made their way into his collections.

Vavilov's career was tragically cut short in 1939 when he was deported to a Siberian labor camp, where he died the following year. But he had lived long enough to produce the first comprehensive picture of agrodiversity. He realized, in the first place, that the world's crop diversity was not distributed randomly; it was instead concentrated in particular regions. In Afghanistan and northern Pakistan, for instance, Vavilov found farmers growing nearly a hundred varieties of "soft" wheat (the kind best suited for making bread)-several times more than had been documented in all of Europe. He argued that the region where a crop showed the greatest number of unique and unusual forms was likely also to be where it was first domesticated (see map, pages 28 and 29). These are also regions where the wild plants from which crops descended-their wild relatives-can often be found growing in nearby natural habitats.

Most of these regions remain "hotspots"of crop diversity today. In the Andes of Peru, for instance, peasant farmers continue to grow thousands of traditional varieties-or "landraces"-of potatoes, corn, and peppers, as well as lesser-known crops such as quinoa (a grain), ulluco (a multihued tuber that thrives at altitudes over 4000 meters), and tarwi (a bean related to the lupine flower).

Vavilov was also one of the first researchers to draw attention to the tremendous environmental and cultural diversity present in traditional small-scale farming. He astutely noted, for instance, that crop genetic diversity was often particularly rich where farmers had to cope with a great deal of variability in local climate, soil conditions, and other environmental factors, as in mountainous regions like the Caucasus and the Andes.

Such regions also contain some of the best examples of agrodiversity on an ecological level. They are ever-changing mosaics of cultivated and fallow fields, hedgerows, orchards, irrigation ponds, windbreaks, woodlots-along with patches and corridors of native vegetation. That, for example, is what anthropologists Christine Padoch and Wil de Jong found when they studied several Ribereño communities on the edge of the Amazon River floodplain in eastern Peru. Ribereños are a people of mixed indigenous and European ancestry, long established in western Amazonia. In just one village, Padoch and de Jong found a dozen distinct kinds of agriculture. Some farmers cut small fields from mature upland rain forest, then burned and planted them with mixtures of up to 60 different crops, following a classic "slash-and-burn" or "swidden" regime. (Such crops are grown intensively for a year or two, then gradually abandoned as the forest regenerates.) Other farmers were planting rice along riverbanks inundated annually by the Amazon floodwaters. Later in the year, these same farmers might clear and plant young regenerating forest for a quick crop of cassava (a starchy tuber). Still other farmers were clearing competing vegetation away from fruit trees within older swidden plots, with the aim of gradually transforming them into native fruit orchards. And nearly every house had a kitchen garden beside it, for a ready source of fruits and vegetables, spices, medicines, and other useful items.

The ecological diversity of traditional farming landscapes can benefit many other species besides people and crops. It can provide important wildlife habitat, as long as hunting pressure is not too extreme. In Europe, for example, over half of all bird species depend on agricultural land for either winter or summer habitat. Tree sparrows and bullfinches sing along English hedgerows; black wheatears and great bustards haunt upland grainfields in Spain after harvests have been gathered in. But as traditional farming has declined across the continent in recent decades, so have populations of scores of bird species.

The biodiversity associated with traditional agriculture is no coincidence-it has arisen precisely because people have actively fostered it. Although, of course, they wouldn't generally put it in these terms, traditional farmers all over the world have long favored biodiversity as a way to maintain longterm productivity. For instance, many indigenous cultures in Mexico and northern Central America have traditionally planted their staple crops of corn, beans, and squash all together rather than in separate fields. Agroecologists Steven Gliessman and M.F. Amador investigated this "polycropping" approach and found that it confers multiple advantages. The beans "fix" organic nitrogen, thereby enhancing soil fertility and improving corn growth. The corn in turn provides a trellis for the bean vines, and the squash plants, with their wide, shady leaves, help keep the weeds down. Overall, the scientists were able to show that total yields of the three crops grown together could be significantly higher than if the same area were sown in monocultures.

Polyculture is also an ancient form of pest control. Planting different crops together tends to create more ecological niches for beneficial organisms, such as parasitic wasps or predatory beetles, which attack pests. Of course, more diverse plantings may also offer more niches for pests and diseases too, but the likelihood of any one organism breaking out in epidemic levels is greatly reduced, since none are likely to affect all crops equally.

Within any particular crop species, genetic diversity has long been important in pest control too. In a genetically diverse planting, some individual plants will likely fare better during an infestation than others, and of course farmers will be quick to notice the best performers. The late Jack Harlan, an economic botanist from the United States, turned up an extreme example of this phenomenon on a visit to Turkey in 1948. He was there to study wheat, and he collected a particularly inauspicious looking specimen in one field: "tall, thin-stemmed, lodges badly [that is, it won't stay upright]...lacks winter hardiness... and has poor baking qualities." Yet when Harlan's seed collection was later evaluated, plant breeders discovered that this variety was "resistant to four races of stripe rust, 35 races of common bunt, ten races of dwarf bunt and [had] good tolerance to flag smut and snow mold." Over the centuries, in years when major outbreaks struck the Turkish fields, that variety might have saved many people from starvation.

Planting multiple varieties of a single crop can provide a kind of "insurance policy" for farmers in other ways as well. In eastern India the staple crop is rice, and in some villages, each farmer sows up to 10 different rice varieties, which vary in the amount of time and moisture they need to mature. That greatly increases the odds of reaping an adequate harvest whether the annual monsoons arrive early, late, sporadically, or in excess. The different maturation times also spread out the labor of planting, weeding, harvesting, and threshing-thereby making life much easier than it would otherwise be.

Diversity also has substantial culinary and esthetic value-another major benefit, as is apparent from the near-universal drive to exploit it in one way or another. Hungarians, for instance, took a particular fancy to chile peppers not long after they were introduced into Europe from the New World at the start of the 1500s. Today Hungarian peppers, known _generally as paprika, are an indispensable element _of the national cuisine and come in a host of varieties with different flavors, colors, and shapes-all of_them developed by farmers and plant breeders over the centuries.

Just about everywhere, you can find farmers who are willing to experiment with new growing practices. But given half a chance, they will usually hedge their bets and reserve some of their land for traditional crops. For several decades, for instance, peasant farmers in the Tulumayo valley of Peru's central Andes have grown potatoes commercially, for the markets of Lima and other cities. Anthropologists Enrique Mayer and Stephen Brush found that the Tulumayo farmers were planting almost 90 percent of their fields to a handful of commercial varieties, but in the remaining 10 percent they mostly grew potatoes for their own cooking pot-and these latter spuds were invariably a diverse collection of traditional landraces. Their refusal to abandon these varieties reflects the central social and ceremonial role that potatoes and other indigenous crops play in native Andean cultures. Yet even the most tradition-conscious farmers now face a host of pressures to abandon their agrodiversity. And many of these pressures have been gathering force for the better part of a century.

Impoverished by Success

At the same time that Vavilov was scouring fields for clues to the origins of crop diversity, another agricultural visionary, the American plant breeder (and later U.S. Secretary of Agriculture) Henry A. Wallace was promoting a new approach to his craft-a technique for creating corn varieties of unprecedented productivity. By Wallace's time, plant breeding as a profession had existed for decades in the United States and many other countries, but professional breeders rarely produced varieties that out-performed the selections that skilled farmers made as a matter of routine.

The emerging science of genetics, however, brought a powerful focus to plant breeding. The new approach favored by Wallace involved making complicated crosses between highly inbred strains of corn, to take advantage of a genetic phenomenon known as "hybrid vigor," in which the first generation of a cross between those inbred strains tended to perform far better than its parents. Wallace also recognized that the high-yield traits were not stable. Planting the seeds of these high-performance hybrids would yield disappointing results, so farmers who wanted to use the hybrid system would have to return year after year to their suppliers for new seed. Hybridization was incompatible with the ancient practice of saving and replanting a part of last year's harvest.

A shrewd entrepreneur as well as a scientist, Wallace knew a good business opportunity when he saw it. His fledgling enterprise, the Hi-Bred Corn Company, was at the forefront of a revolution that would, in a matter of decades, transform U.S. agriculture from a family-based craft to an increasingly centralized commercial industry. (Wallace's company, now a DuPont subsidiary known as Pioneer Hi-Bred, has become the world's largest seed producer.) Jack Kloppenburg, a rural sociologist at the University of Wisconsin, has written that Wallace "understood, perhaps better than any American of his generation, the process by which agricultural production was being integrated into modern industrial capitalism." In 1930, virtually the entire corn crop (and all other crops as well) consisted of traditional "open-pollinated" varieties, whose seeds could be readily saved and replanted. By 1965, nearly 95 percent of all U.S. corn acreage was in hybrid varieties.

Many other aspects of the corn crop changed between 1930 and 1965 too. Muscle power-both human and animal-was replaced by the internal combustion engine. Breeders standardized corn ripening times and stalk height to accommodate an increasingly mechanized harvest. To boost yields further, hybrid varieties were bred to consume as much fertilizer as possible; over that 35-year time-span, U.S. fertilizer use increased 17-fold. Corn yields per unit area quadrupled, allowing the total harvest to rise dramatically even as the annual area planted to corn declined. The farm population declined as well-in the northern corn belt, for instance, the number of farms shrank by 35 percent between 1935 and 1960. And one of the most revealing changes of all involved crop diversity. In 1930 there would have been hundreds if not thousands of local corn varieties in the country's fields. By 1969, a mere six hybrids accounted for 71 percent of all U.S. corn area.

What happened to corn has happened to many other crops as well. In the United States, varietal diversity in most crops plummeted over the course of the 20th century; on average, over 90 percent of the varieties grown in the country a century ago are no longer in commercial production or present in a major seed storage facility. Among lettuce varieties, for example, the losses total 92 percent. Out of 408 pea varieties shown in the seed catalogs of 1903, only 25 have been relocated-a 94 percent reduction. By 1970, just two varieties of peas accounted for 96 percent of the U.S. commercial crop. Nor is this problem peculiar to the United States; although the data can be hard to come by, most of the industrialized world seems to have suffered similar losses.

The genetic diversity of livestock has also been in decline. Jules Pretty, a rural development expert who directs the Centre for Environment and Society at the University of Essex in the U.K., notes that "In Europe, some 750 breeds of horses, cattle, sheep, goats, pigs, and poultry have gone extinct since the beginning of the 20th century; and a third of the remaining 770 breeds are in danger of disappearing by 2010."

During the 1950s and 1960s, the agricultural "Green Revolution" brought extremely uniform, "high input" varieties to the developing world. (In contrast to landraces, these crops don't generally perform well without substantial doses of artificial fertilizer, pesticides, and water-hence "high input.") In many areas, grain production increased sharply-but at a substantial cost. The old polycultural landscape yielded to monoculture: the new regime usually produced only one commodity, instead of a range of foods, medicines, and so on. And in the staple crops of Asia, Latin America, and Africa, the disease of genetic erosion emerged swiftly. One single variety of wheat blanketed 67 percent of Bangladesh's wheat fields in 1983, and some 30 percent of India's a year later. In 1982, a single high-input rice variety known as "IR-36" was grown on more than 11 million hectares in Asia-an area the size of Guatemala.

In industrialized countries, a great many crop varieties had vanished from field and orchard without any apparent public concern. But by the late 1960s, plant breeders like Erna Bennett and Sir Otto Frankel were raising the alarm over the potential impact of the Green Revolution in developing countries. The rapid response reflects the importance that breeders attached to the world's centers of crop diversity, nearly all of which are in developing countries.

That concern has nothing to do with the picturesque appeal of traditional farming-it's based on the "real world" recognition that agriculture is a form of biological warfare. Under the demanding conditions of high-input commercial farming, even the most rigorously bred varieties do not remain viable for long. Faced with rapidly evolving insects and diseases, with accumulating salt residues from irrigation, and with an assortment of other stresses, the typical commercial variety has a useful life of only about 5 to 10 years. This rapid turnover of varieties has been termed "diversity in time" by plant breeder Don Duvick, in contrast with the "diversity in space" seen in traditional farming. Keeping a constant stream of new varieties in the pipeline requires an extensive breeding infrastructure, involving both the public and private sectors. Professional breeders are now engaged in an enormous high-stakes relay race to develop ever more robust varieties before those already in commercial fields succumb to current stresses.

Even now, in the era of biotechnology and after over a century of professional plant breeding, commercial agriculture is still entangled in a kind of breeder's paradox: the commercial crops remain dependent on regular genetic infusions from the land­races they are displacing. Timothy Swanson, an economist at University College in London, estimates that plant breeders still return each year to landraces and their wild relatives for about 6 percent of the germplasm lines used in their breeding. (The remainder are advanced breeding lines and established commercial varieties.) Six percent per year is a pretty substantial dependence, and there is little prospect of lessening it anytime soon. It is true, of course, that biotechnology has effectively broadened the gene pool available for creating new varieties, but most of the really useful traits, such as increased yield and drought tolerance, involve complex combinations of genes, and cannot be transferred from unrelated or even distantly related organisms. For these traits, breeders must continue to draw on landraces and their close wild kin.

The industrialization of agriculture has also dramatically reduced ecological diversity in farm landscapes. The commercial regime demands an economy of scale, so as production intensifies, the tendency is to bring as much of the farmscape as possible into the monoculture and to reduce or eliminate fallow periods. Under such pressure, the old patchwork of wildlife habitat generally vanishes-witness the population crashes of farmland birds in Europe, or the declines in ducks that breed in the "prairie pothole" wetlands of the U.S. upper midwest. Crop resources lose out in this simplification process as well. For example, according to Gary Paul Nabhan, an ecologist at the Arizona-Sonora Desert Museum, the wild chiles and gourd plants that used to grow abundantly along the margins of bottomland fields in northwest Mexico have declined markedly, now that those fields have been converted into intensive monocultures.

Nor is this simplification just a matter of losing species. It also entails an impoverishment of ecological function: the "services" provided by the old ecological diversity go into decline as well. That's why, in simplified commercial farmscapes, farmers have to apply large amounts of artificial fertilizer to compensate for the loss of processes like fallowing, which restore fertility naturally. They have to apply chemical pesticides to compensate for the loss of natural pest controls like polycropping and complex crop rotations. And if they're growing crops that aren't wind pollinated, they may have to rent hives of insect pollinators (usually the European honeybee), to compensate for the loss of native insects.

The side effects of these substitute services are considerable. Every year, for instance, an estimated 3 million people are poisoned by pesticides. Some of these chemicals are highly persistent, and contamination of groundwater is a growing concern in many heavily farmed regions. (See "Groundwater Shock," January/February 2000.) Such problems can reach far beyond the fields themselves. For example, fertilizer-laced run-off from farms in the U.S. midwest is borne by the Mississippi River into the Gulf of Mexico, where it is apparently helping to trigger massive algal blooms. The blooms deplete the water of oxygen, creating a "dead zone" in which nearly all marine life is asphyxiated-including much of the rich fishery for which the Louisiana coast is famous. Last year, the annual dead zone was the largest ever, covering nearly 20,000 square kilometers, an area the size of the state of New Jersey.

In addition to the damage they're inflicting, these substitute services tend to be much less stable than their traditional analogs because they lack natural complexity. They have little "built-in redundancy" and that makes them, in a sense, accidents waiting to happen. Take pollination, for example. Gary Paul Nabhan and entomologist Stephen Buchmann have documented widespread declines in efficient native pollinators of many crops in North America, from blueberry bees in Maine to alkali bees that have a fondness for alfalfa in the Great Basin. As a result, North American vegetable and fruit production has become highly dependent upon the introduced European honeybee.

Though not particularly efficient pollinators, honeybees are consummate generalists, readily visiting a wide variety of crops, and they are easily managed by people. Over the past several decades, however, millions of North American honeybee colonies have been lost due to a host of problems, the most recent of which is a widespread infestation of two types of introduced parasitic mite. According to the U.S. Department of Agriculture, the country's bee industry is in an "unprecedented crisis," and Nabhan and Buchmann warn that nationwide honeybee declines could reach 80 percent, causing crop losses that may exceed $5 billion annually.

Yet amid the many problems created by what we now consider to be "conventional" agriculture, there are many signs of hope. Scattered about the farming landscapes of developing and industrialized countries alike are farmers who seek alternative approaches to their craft. Some are doggedly maintaining their traditions, like the rice farmers in Java who continue to plant their local, long-stemmed rices in the face _of intense government pressure to convert to monocultures of high-input varieties. Others, like many small-scale organic producers in Europe and the United States, are experimenting with various forms of polyculture. Such efforts represent the future of agrodiversity.

Productivity in a Broader Sense

Two of modern agriculture's luckiest moments may have come in the form of failure. In 1970, a few years after scientists began raising the alarm about the loss of crop genetic diversity, the U.S. corn crop was struck with a leaf blight and the harvest collapsed in many states. A year-and-a-half later, the Soviet winter wheat crop failed after a prolonged winter followed by an unusually dry spring. In both cases, the crop's vulnerability was traced to the genetic uniformity of the varieties planted. Crop genetics had suddenly become a matter for international policy, and in 1974, international aid donors and agricultural research centers joined forces with the United Nations to establish the International Board for Plant Genetic Resources-now known as the International Plant Genetic Resources Institute, or IPGRI.

The institute and its various allies initially tended to see their job as essentially a rescue mission. IPGRI's mandate was to assemble a global network of gene banks-facilities that store large quantities of carefully maintained seeds, which are grown out occasionally for harvest back into the collection. (Plants with seeds that cannot be stored for long periods are usually maintained as living nursery stock.) Today, the network includes university breeding programs, government seed banks, and international agricultural research centers. The total number of sampled varieties, or "accessions," now exceeds 6 million. Not surprisingly, most accessions have been drawn from the world's leading staple crops, especially wheat, rice, corn, and beans.

These accessions are a priceless resource. Professional breeders use them as a matter of routine, and they are called upon in times of crisis too. They have, for instance, been used to resupply traditional varieties to regions where agriculture has been severely disrupted by war or famine-as when traditional rice varieties were restored to Cambodia in the 1980s, after the overthrow of the Khmer Rouge.

There is more to seed-saving, however, than what is practiced in large, centralized gene banks. About the same time that IPGRI was founded, Kent and Diane Whealy, a recently married couple in the U.S. state of Iowa, received seeds of a pink tomato, a runner bean, and a morning glory variety from Diane's grandfather, a lifelong gardener. The varieties had been grown in Diane's family for over four generations. Her grandfather died shortly after making his gift, and the Whealys realized that the fate of these varieties was now in their hands.

Curious about how many other people were maintaining such "heirloom" seeds, they began writing to gardening magazines and contacting other backyard gardeners. Thus was born the Seed-Savers Exchange (SSE), a network now including over 8,000 members who grow and trade heirloom and "open-pollinated" varieties of fruits, vegetables, and flowers-including such hard-to-find items as Wolf River apples (which can weigh up to a pound each) and the Menominee squash, a variety similar to those once grown by Native American farmers in the U.S. midwest. This year, the SSE catalog contains over 11,800 varieties available for exchange or purchase-some 4,000 more than are offered by the entire mail-order garden seed industry in North America, an industry that has undergone unprecedented consolidation in recent decades.

In developing countries, most farmers still save and replant their own varieties-at least for subsistence use. Yet the leadership of especially visionary farmers remains essential to maintaining diversity. In the Garhwal region of northern India, for example, a farmer named Vijay Jarhdhari has sparked a modest revival of the varieties traditionally used in that region's hill farms. After becoming disenchanted with the side-effects of the agrochemicals required by high-input rice and soybean strains, Jarhdhari and his wife decided to return to the older varieties of rice, millet, lentils, and other crops previously grown on the region's farms. But they themselves had lost these seeds, and as Jarhdhari began to ask around, he found that many traditional varieties were on the brink of vanishing altogether.

Persistent searching eventually paid off. Jarhdhari and a few other like-minded farmers managed to assemble a collection of more than 100 traditional rice varieties, 80 beans, and other regional grain and oilseed specialties. Beginning in 1990, they initiated a "Save the Seed Movement" that has attracted hundreds of participants to some events, and their collection of local varieties continues to grow. Farmers active in the movement are also eager to promote traditional intercropping methods that incorporate up to a dozen grains, herbs, and vegetables in an integrated cycle. Jarhdhari argues that the economic effects of such efforts are as important as the ecological ones. "It is not enough to simply collect seeds," he says. "We have to make farming in the villages in Garhwal worthwhile again."

Farmers like Jarhdhari are natural allies for an innovative form of crop development that is attracting the attention of more and more professional plant breeders. Typically, professional breeders strive to create uniform or "pure-bred" strains of the crops they are working with. These pure-bred lines are designed to be widely adaptable, and it is only towards the end of the breeding process that the lines are actually evaluated by farmers. A growing number of participatory programs, however, seek to involve farmers in all stages of the breeding process. In the most innovative ones, breeders and farmers work directly in the latters' fields to evaluate, select, combine, and improve a wide range of varieties-including both local strains and promising varieties from other regions. This approach has the potential to combine the best of both worlds: it can improve the quality of locally adapted agriculture without resorting to varietal uniformity. Plant breeders John Whitcombe and Arun Joshi have conducted such programs for rainfed (that is, non-irrigated) crops in India and high-altitude rice in Nepal, and they argue that these decentralized breeding approaches can maintain-and potentially even enhance-local genetic diversity.

With the help of scientists and conservationists, innovative farmers are also restoring ecological diversity-and the more durable set of "services" that it provides. In Iowa, the state with the second largest agricultural sector in the United States (after California), a 500-member group called Practical Farmers of Iowa (PFI) is collaborating with university researchers to identify practices that can enhance the ecological integrity of farmland while cutting costs for the farmer. Since 1985, PFI members have carried out over 400 field trials on alternative crop rotations and weed management methods, on non-crop plantings along field margins to maintain beneficial insect habitat, and many similar innovations. Pesticides, especially, are expensive, and with Iowa's two leading crops-corn and soybeans-selling in 1999 for substantially less than what it cost to produce them, an increasing number of farmers are interested in using diversity to cut costs.

If such approaches are to succeed, however, they must prove themselves not just in the field but in the market. Innovative farmers need consumer support-and increasingly, they're getting it. The global market for organically grown foods, for example, has expanded by 20 percent annually during the 1990s. Another strong sign of popular support is the _growing number of seasonal farmers' markets in North America and Europe, where producers sell locally grown foodstuffs directly to consumers. According to Jules Pretty, at least 2,400 farmers' markets operate in the United States, serving some 1 million patrons each week. Through this direct retail, farmers collect a higher return for their produce than they would get from the major food processors, and they are able to sell many more varieties than the processors would buy. One study in Madison, _Wisconsin found that during a three-month period, the bustling weekly farmers' market offered over three times as many distinct crop varieties as did the city's supermarkets.

Yet another sign of the growing consumer appreciation for agrodiversity is the emergence of Slow Food, an international network of some 70,000 chefs, artisanal farmers, and food aficionados. Slow Food recently inaugurated an "Ark of Taste" program to highlight exceptional foodstuffs in danger of disappearing, and to encourage consumers and restauranteurs to revive them. Among the listings to date are rare varieties of crops and domestic animals, such as the porc noir gascon, a small, black French pig known for the quality of its meat, but now kept only in small numbers in the high Pyrenees and the Garonne region. Also included are certain small-scale farm products, such as krassotyri, a distinctive sheep's milk cheese streaked with wine dregs, which is _produced now by only a few women on the Greek island of Kos.

Discerning consumers can make a difference when it comes to the major agricultural commodities too. For instance, traditional coffee plantations in Latin America provide important habitat for many songbird species, particularly those that migrate south each year from North America. In these plantations, shrub-sized coffee plants are generally grown in partial shade, under a varied canopy of native forest trees, usually several nitrogen-fixing legume species. Beginning in the 1980s, however, many growers began planting new "sun coffee" varieties, which promised higher yields. Sun coffee requires full light to produce well, so the plantation overstory has begun to disappear. The new varieties also require much heavier applications of pesticide and fertilizer-a further ecological disruption. Luis Gaitán, a Guatemalan scientist who has inventoried birds, reptiles, and insects on sun-grown coffee plots, calls them "biological deserts."

Recognizing the environmental threat posed by sun coffee, a conservation organization called the Rainforest Alliance has established a certification program for coffee produced on shade plantations. Participating farms must maintain forest cover and meet a series of environmental and social criteria for sound management, such as limiting soil erosion and providing workers with environmental education. Certified shade-grown coffee is now available through at least 24 different coffee distributors and mail-order retailers in the United States.

As encouraging as these examples are, the scale of what remains to be accomplished is daunting. In the case of shade coffee, for instance, only about 41,000 hectares of plantations have been certified to date, out of some 7 million hectares of coffee in all of Latin America-and the area devoted to sun varieties and other forms of intensive production continues to rise. In general, such efforts to promote diversity are still a small part of the agricultural sector.

The current momentum of agro-industrial development would be considerably reduced were it not directly fostered by a slew of policies and subsidies in nearly every country. In both the United States and the European Union, for example, most government crop supports target just a handful of major crops, rather than the more diverse crop combinations favored by smaller farms. It's hardly surprising, then, that most beneficiaries are large commercial farms, not small-scale farmers. In many developing countries, such as those in southern Africa, farmers cannot qualify for government agricultural credit programs unless they agree to plant high-input varieties.

Governments commonly cite laudable objectives for these policies, such as increasing national self-sufficiency in staple foods. But monoculture farming does not make ecological sense, and increasingly its economic justification is coming under question too. A growing body of evidence suggests that large operations are actually far less productive and efficient than areas of equivalent size and quality worked by smaller producers. And big operations generate far more waste and pollution per unit area.

Ultimately, the fate of agrodiversity will be decided by the degree of importance we attach to farming as a social activity. Diversity will not persist without thriving rural communities to support it. Conversely, the preservation of diversity can yield major social benefits. That principle is reappearing even in the Red River valley, in the activities of people like Jaime DeRosier, a farmer who is not content with the standard wheat and barley regimen. DeRosier also grows organic sunflowers, corn, and soybeans in complex rotations, deploying up to six different cover crops to keep pests and weeds under control. He plants nitrogen-fixing legumes to boost soil fertility, and allows for occasional summer fallow periods. He is even thinking of adding specialty crops like green beans and sugar beets. As one of the few financially stable farmers in the region these days, his advice is constantly sought by other growers looking to make a change for the diverse.

In farmers like Jaime DeRosier and Vijay Jarhdhari, we have the makings of another and very different kind of Green Revolution-one that could put global agriculture on a sustainable footing. But this is not a transition that farmers can make on their own. The question is: are the rest of us-as consumers, voters, and policy makers-willing to back them up?

John Tuxill is a research fellow with the Worldwatch Institute. This is the first in a series of articles on the environmental and social importance of agrodiversity.

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