Will We Run Low On Food?

By EUGENE LINDEN

Bent Skovmand is not exactly a household name, but he has more to do with the welfare of the earth's 5 billion people than many heads of state. As a plant breeder at CIMMYT, the internationally funded agricultural research station in El Batan, Mexico, he spends his days in silent battle with threats to the world's wheat crop. Recently Skovmand discovered a rare strain of wheat from eastern Turkey that is resistant to the Russian aphid, an invader that has so far cost American farmers $300 million. By using the Turkish strain to develop hearty new hybrid wheats, CIMMYT breeders may help growers outwit the aphid.

Unfortunately the strains of crops that seem to have almost magical qualities are becoming ever harder to find. As farmers go for the highest possible yields these days, they all want to use the same kind of seeds. Individual crops share more genetic material, and local varieties are vanishing. Moreover, as the explosive growth of the world's population causes more farmers to turn more forest land into fields, wild species of plants are getting wiped out. Potentially valuable food sources are lost -- forever -- before they are even discovered. The world is losing a marvelous diversity of genetic material that has enabled the plant kingdom to overcome pests, blights and droughts throughout the ages.

Plant breeders have used this genetic diversity to help fuel the green revolution and keep agricultural production ahead of population growth. But as the raw material of the revolution disappears, the food supply becomes more vulnerable to catastrophe. Skovmand, for one, is not optimistic about the prospects for the coming decade. "The world has become complacent about food," he says. "In the 1970s the surprise was that India could feed itself. In the coming years the surprise may be that India can no longer feed itself."

Ever since Thomas Malthus' 1798 Essay on the Principle of Population proposed that human fertility would outstrip the ability to produce enough food, human ingenuity has consistently belied such predictions. Books such as Paul Ehrlich's The Population Bomb in 1968 and the Club of Rome's 1972 study The Limits to Growth raised fears that unchecked population growth might lead to mass starvation. Later in the '70s, Lester Brown of Washington's Worldwatch Institute argued that the world's farmers were already pushing the practical limits of what good land, high-yield crops, irrigation and artificial fertilizers and pesticides could deliver.

The Malthusians, however, have consistently underestimated how much the technological wonders of the green revolution -- along with the ability of farmers to make good money growing crops -- can spur food production. Ehrlich and Brown have long predicted that food prices would rise as agricultural production fell short of demand, and they have been wrong. India, where 1.5 million people died in a 1943 famine, became a grain exporter by 1977, even as it doubled its population. Farmers planting short, seed-laden wheats developed by Nobel laureate Norman Borlaug at CIMMYT had to post guards to protect the riches in their fields.

Beginning in the mid-'80s, however, the momentum of the green revolution slowed dramatically, especially in parts of India, China and Pakistan. In India's Punjab state, yields of rice and wheat have begun to flatten despite increasing reliance on fertilizers and better use of water. Elsewhere in Asia, rice researchers have failed to raise yields significantly for more than two decades. Hidden costs of the green revolution have begun to surface all around the world: the amount of irrigated land, which produces 35% of the food supply, has been declining in per capita terms. One reason is that fields become poisoned with salts left behind when irrigation water evaporates. Looming in the future are the unknown agricultural impacts of global changes such as ozone depletion in the upper atmosphere and the greenhouse effect.

The short term is not too rosy either. The U.S. corn and soybean crops are currently suffering from a severe drought in the Midwest. And, for a variety of reasons, poor harvests are predicted this year in China, India and the Soviet Union.

The combination of both immediate and long-range threats to the food supply has brought back the old alarming questions: How much longer can the world deliver adequate food to human numbers relentlessly expanding at the rate of 91 million a year? Is it possible that the Cassandras will soon be right?

Many agricultural experts are taking doomsayers more seriously. A new cause of concern is the steady loss of genetic diversity, which has made the food supply less stable and reliable than in the past. With farmers growing similar crops in similar ways, diseases and droughts have more impact than they would if planters grew a diverse array of crops. Senator Albert Gore of Tennessee is convinced that the decline of diversity is one of the greatest threats facing world agriculture. "We may see a significant number of crops become functionally extinct," he says, "enjoying bumper crops until one day the hammer falls in the form of a blight they cannot handle."

According to economist Peter Hazell, who conducted a study of crop volatility for the International Food Policy Research Institute, the likelihood of major food shortfalls has doubled during the past four decades. India, for instance, relies heavily on one type of fast-growing wheat, called sonalika, that is susceptible to several diseases. One epidemic in this crop could wipe out India's entire grain surplus.

Plant breeders can provide India with wheat strains resistant to the pests that threaten sonalika, but, says Michael Strauss of the National Academy of Sciences, "this is not a battle you win just once." Disease germs and insects continually evolve, developing resistance to pesticides and seeking out vulnerabilities that enable them to penetrate crop defenses.

A mix of strains minimizes this damage. But more and more of the world's basic crops now share genetic material. Most high-yielding wheats and rices derive their short, sturdy stature from just a few ancestors. While these genes may be tough, the genes transferred with them may contain a hidden vulnerability that could allow pests to lay waste to huge areas. Observes plant breeder Garrison Wilkes of the University of Massachusetts at Boston: "Imagine what a burglar could do if he got past the front door of a building and found that all the apartments shared the same key."

One promising solution to this problem is for breeders to draw genetic material from a wide variety of sources so that bugs and blights are forced to breach many types of defenses. The new tools of biotechnology allow scientists to identify particular genes and thus predict which strains will exhibit such desirable characteristics as disease resistance or drought tolerance. Crossing many varieties can then create the best possible mix of traits. Entomologist John Mihm and CIMMYT geneticist David Jewell are combating a corn borer that costs tropical farmers as much as 50% of their crop. The two scientists hope one day to create hybrid corn with resistance from a maize local to Antigua as well as the phenomenal defenses of Tripsacum, a wild grass that is related to corn.

Although plant scientists rely on traditional crossbreeding, they are experimenting with actual genetic engineering. Eventually they hope to take individual genes from one strain and put them into the cells of another. Researchers expect to isolate genes from plants that have found ways to cope with ultraviolet radiation, drought, salty soils and other changes future crops may face as a result of mankind's meddling with the earth and atmosphere.

But such techniques will gradually have poorer results if the genetic catalog scientists work with is shrinking. When so many farmers switch to the most popular strains, their wild ancestors and traditional crops that have become adapted to local conditions for centuries (called land races) can easily disappear. Urban development paves over traditional crops and good soil, because cities have usually grown up near the richest land. Calvin Sperling, the U.S. Department of Agriculture's chief plant explorer, believes coastal development along the Mediterranean may have already caused the disappearance of many land races of beets. And war almost always takes a toll. One casualty of the recent conflict with Iraq may be the loss of rare breeds of wheat as farmers forced from their fields eat their seeds to survive.

Agriculture's main defense against the loss of diversity has been the establishment of seed banks, which collect and preserve crop strains. International agencies have helped set up a worldwide network of eight banks that hold myriad varieties of seeds for 25 important food crops. These international centers serve as vital backstops for national seed collections, which are sometimes carelessly maintained.

No one contends that these seed banks can completely halt the diversity drain. While impressive collections have been built for such major crops as wheat, corn and rice, efforts to accumulate samples of vegetables and lesser- known cereals have been much more spotty. During times of unrest, people have raided and eaten seed collections. The director of a research station in Aleppo, Syria, was so concerned with the threat of war last year that he shipped precious wheat seeds to CIMMYT before allied action began against Iraq.

Another strategy for preserving diversity is to encourage farmers to maintain a variety of traditional crops. But the global movement of people into cities creates tremendous pressures on farmers to grow uniform, easily transportable crops. This situation will only get worse. By 2000 there will be about 400 cities with more than 1 million inhabitants each, containing one- sixth of the world's population.

The rise of megacities in the developing world also thwarts agricultural policies that would stimulate food production in the countryside. Mindful that governments get overthrown by city dwellers and not farmers, many Third World regimes artificially lower crop prices to placate their urban populations. In Egypt, livestock growers find it cheaper to feed their animals subsidized bread than to produce the grain themselves. This absurdity is unlikely to change, because a past attempt to hike the price of bread produced riots in Cairo.

Such unrest may become more frequent in the coming years. Donald Winkelmann, CIMMYT's director general, notes that a decade ago, India's farmers could thrive even as wheat prices dropped, because production costs fell faster. Now it is harder to lower costs and, Winkelmann says, "India may not be able to count on cheap food as it has in the past as an element of industrialization." He expects crop prices to rise after mid-decade, as demand increases faster than supply.

Lester Brown has renewed his earlier predictions that world population is reaching the limit of what the planet's land can support. Per capita food production is already declining, he points out, in Africa and South America. Ethiopia has suffered its tragic famines, Brown contends, partly because the country's population has outstripped the productive capacity of its fields. But World Bank analysts disagree, arguing that Ethiopia's agricultural failures stem more from the policies of the recently ousted Mengistu regime, which paid farmers rock-bottom prices and created no incentive to conserve resources.

Just Faaland, the director general of the International Food Policy Research Institute, maintains that what Brown sees as limits are really only impediments: "It's true that fertilizer yields have stopped growing, that crops are more vulnerable to pests, and it has become more difficult to find arable land and water, but we can move these limits. It is not reasonable to project a logical and necessary catastrophe." Dennis Avery of the Hudson Institute in Indianapolis goes further in his new study Global Food Progress 1991. He argues that financial investment, not fertile soil, is now the limiting factor in food production. Idle and underutilized cropland in the U.S. and Argentina alone, he says, could feed an extra 1.4 billion people.

When it comes to predicting food prices and supplies, the optimists so far have a much better track record than the pessimists. But few experts would deny that as the human population grows, threats to the food supply become ever more dangerous. And mankind is losing the weapons to fight those threats, as it allows the irreplaceable diversity of the plant kingdom to disappear.