How to feed the world

After more than 20 years of weeding his rice paddies by hand, Takao Furuno of Japan of wondered if organic farming was worth the trouble. Then something changed his life.

Ducks.

The wild fowl, floating in his fields, inspired him to try an old Japanese technique of raising ducklings alongside the rice. The results surprised him. The birds ate the weeds and pests he'd worked so hard to eliminate. And their droppings nourished the rice, raising yields. Mr. Furuno, author of "The Power of Duck," has since started rotating crops and has added fish to flooded fields. His system is spreading to other Asian producers.

Furuno's ways are a prime example, observers say, of what could be the future of agriculture.

But it's only one of several visions. At the other extreme, in hungry Kenya researcher Florence Wambugu is using biotechnology to create sweet potatoes that resist pests.

The genetically manipulated sweet potatoes boast twice the yield and retain more of the nutrition than their conventional cousins. By taking this route, other observers say, feeding the world will require that fewer of the earth's forests be hewn for farming.

Ever since the world embarked on its biggest population boom three centuries ago, international agriculture has accomplished an amazing feat. It has managed not only to keep up with but to exceed the demographic increase. The result: A greater share of people eat better than at any time in history and, although hunger persists, its grip on the world is loosening.

Now, agriculture faces one final demographic spurt - a nearly 50 percent increase in the world's population before it levels off at around 9 billion people in 2050. And doubts are creeping in about whether the industry has the wherewithal to work its magic one more time.

"We feed ourselves largely on those earlier gains, which we call the Green Revolution," writes Richard Manning, author of "Food's Frontier: The Next Green Revolution." "Now we are in need of another such leap, but we lack the technology to effect it."

"We have to come to terms with our life-styles," adds Fred Kirschenmann, director of the Leopold Center for Sustainable Agriculture at Iowa State University in Ames. "We have to bring our species in balance with the rest of the species. I'm not very sanguine about that because if you look at the technologies that we've developed in the past, they always have had some ecological fallout."

Starting in the 1700s, Europe fed its burgeoning population by expanding agricultural production, especially in its colonies. That was acceptable when the world retained many of its forests. Now that land under cultivation represents nearly a third of the earth's land surface, further expansion looks environmentally suspect. So does today's conventional farming.

But alternatives have their own problems. Organic agriculture can't produce enough food to feed today's world. And biotechnology is running into widespread skepticism.

If it weren't for the environmental questions, such doubts about future food production might seem laughable. After all, the record of the past 40 years looks stellar. Average cereal yields have more than doubled, according to a University of Essex study. The world's farmers produce 25 percent more food per person, even though population totals have nearly doubled. And the price of food has fallen 40 percent (adjusted for inflation), which has alleviated hunger and caused some observers to forecast that the world could conquer malnutrition in this century.

The problem with this record lies with its effects outside agriculture. The fertilizers and pesticides of conventional (or high-input) agriculture foul drinking water, increase insects' resistance to pesticides, and choke irrigated soils with salt. Nearly 4 million acres of irrigated land are lost each year to this salinization, costing some $11 billion in reduced productivity annually, according to a satellite mapping project by the World Resources Institute, an environmental think tank based in Washington, D.C. The same report found that more than 40 percent of the world's agricultural land exhibits moderately degraded soils.

High-input agriculture not only fouls resources, it uses them up, especially water. Already, irrigation takes 70 percent of the fresh water the world uses each year. Unless it can be made more sustainable, irrigation will lead to increasing competition between farmers and urban dwellers.

Even if conventional farming could solve these environmental dilemmas, it no longer packs much of a productivity punch. Between 1950 and 1960, US farmers saw their average grain yields soar 45 percent. By 1990, a decade's worth of increase boosted yields only 10 percent, writes Mr. Manning.

The question for policymakers is where to turn now. If the world encourages farmers to put more land into production, the loss of forests and other natural habitat will hurt the environment. At one extreme, to convert a land mass equal to the US (including Alaska) would rival the effects of global warming in its impact on the environment, scientists at the University of California at Santa Barbara warned two years ago.

Organic farming, with its emphasis on natural and renewable inputs, shows promise in reducing some of agriculture's environmental problems. And it's growing quickly. Certified organic crop land for corn, soybeans, and other major crops has more than quadrupled since 1992, according to the US Department of Agriculture (USDA). And organic poultry and dairy farming have grown even faster. But even so, organic farming represents a tiny share of agriculture. In the US, for example, it takes up far less than 1 percent of the nation's farmland. And in Europe, where organic has gained a stronger foothold, only Sweden boasts double digits (11 percent).

Unfortunately, organic agriculture alone can't feed today's world, mush less the nearly 3 billion extra people expected by 2050. The limiting factor: It requires nitrogen-rich manure instead of man-made fertilizer. At most, according to Vaclav Smil, a Canadian geographer and author of "Feeding the World: A Challenge for the Twenty-First Century," farming without synthetic fertilizer could feed 2 billion to 3 billion people.

"It's nuts," says Dennis Avery, director of global food issues for the Hudson Institute, a conservative think tank based in Indianapolis. If the US, for example, wanted to go totally organic, it would have to increase its cattle herd ninefold and convert almost the entire US land mass to pastureland to create enough manure, he calculates. "We'd have room for cities and roads and manure production, but we wouldn't have the space for crops or Yellowstone National Park."

That leaves biotechnology, which Mr. Avery favors, but which has run into political opposition, especially in Europe, Japan, and parts of Africa. Currently, the US is considering going to the World Trade Organization over European Union moratoriums on biotech crops. The resolutions of such disputes could determine if and how quickly the technology spreads. Last year, biotech crop acreage rose 12 percent worldwide.

Perhaps these debates over farming techniques cloud the larger issue of mind set. Will agriculture stay industrially focused, or will it move to a more environmentally sensitive model, where biology rather than chemistry becomes the first line of action? Such a move wouldn't rule out the use of biotechnology or more conventional solutions. It would hold them in reserve.

Consider the South's long fight against cotton pests. Dr. Lewis and other government scientists are working on biological means of controlling these natural enemies. For example, cotton plants send out SOS signals when attacked by caterpillars, which attract a tiny wasp that feeds on the caterpillar. By enhancing the signaling and engineering plants to switch their insect resistance on and off, cotton could protect itself without letting the insect build up resistance to its defenses, he says.

But the boll weevil is an imported pest. So in the late 1980s, Southeastern states began using new monitoring technology and old-fashioned chemicals to zap the weevils. Using a chemical pesticide proved controversial, Lewis says, but the results are hard to argue with. Georgia's cotton crop has recovered to levels not seen since 1915. More important, the weevil's disappearance has allowed farmers to cut back on other pesticide use.

"It's not products; it's understanding the process," Lewis says. "The value is not whether it's synthetic but whether it will work and be renewable."