Feeding the world with biotech crops.
Genetic engineering is likely to be a major factor in raising the per-acre yields of crops and livestock during the twenty-first century--perhaps the major factor.
World rice yields have been stagnant for 15 years but, thanks to biotechnology, may now soar dramatically. Researchers from Cornell have managed to insert two genes from wild relatives of the rice plant into the top-yielding Chinese hybrid rice varieties. Each of the two wild genes increased the yields of its test variety by 17 percent. Used together, the wild genes are expected to boost the world's potential rice yields by 20--40 percent. That may save more than 123 million acres of the world's wildlands--or four times the land area of Pennsylvania--from being plowed for rice production.
How did the researchers raise the yields? They already had the seeds of the rice plant's wild relatives in gene banks, but the wild relatives wouldn't interbreed with the domestic rice varieties. (Over time, they had become too different.) So the researchers used genetic engineering to create a "wide cross"--an arranged marriage between different species.
The higher crop yields do require more plant nutrients, which simply means that farmers need to apply higher levels of fertilizers containing the nitrogen, phosphate, potash, and 26 trace minerals important to plant growth.
The tropics are urgently short of good cropland. This is the main reason poor farmers take their families into the tropical rain forests in a desperate effort to grub out a subsistence amid heat, humidity, snakes, and disease.
Now genetic researchers in Mexico have found a way to overcome the aluminum toxicity that debilitates crop plants in much of the best potential cropland throughout the tropics. Raising yields on the land already being farmed will take much of the food production pressure off the tropical rain forests.
Plant breeders had long known that some plants succeed on the big acid-soil savannas in the tropics because they secrete citric acid from their roots. (The acid ties up the aluminum ions.) Plant breeders had been searching for existing plants they could crossbreed for the citric acid feature but hadn't found any.
Instead, the Mexican researchers took the direct route, through genetic engineering. They took a gene from a bacterium that codes for citric acid and inserted it directly into tobacco and papaya plants (along with the genetic programming that causes a gene to be expressed in the roots). Presto, they came up with crops for the tropics that fend off aluminum with their own citric acid secretions. The researchers are now working to add the acid secretion to corn, wheat, and other key crops.
This represents a huge advance, because aluminum toxicity cuts crop yields by up to 80 percent on 30-40 percent of the world's cropland!
How genetic engineering works
Nothing demonstrates the speed of modern science better than our sudden breakthrough in biotechnology.
Until 1947, we had no clear idea how nature transmitted its incredibly complicated instructions telling new organisms how to grow. Then researchers discovered that we each inherit a double coil of DNA--deoxyribonucleic acid. DNA, and the sequence of genes within it, determine our biological heritage.
Today, we can insert DNA into organisms with short electric pulses or with DNA-coated gold beads shot from "gene guns." Even high school students routinely separate the bits of DNA that carry genetic instructions.
That doesn't mean genetic engineering is simple or easy:
* Most of the world's biodiversity is in tropical forests, mountain microclimates, and remote, fetid swamps, so gathering the DNA can be slow, and dangerous, work.
* Preserving the world's DNA resources in gene banks where researchers can get at them is itself a costly and demanding endeavor.
* The greatest challenge is figuring out what pieces of DNA to put where to achieve a beneficial result. (No one is suggesting crossing an elephant with a sabertooth tiger to produce a big, vicious predator. Nor crossing crabgrass with poison ivy to create an itching, pervasive nuisance. That's why genetic engineering experiments are carefully regulated.)
Still, the technology is becoming more and more practicable.
Some critics say we shouldn't take the risks of "playing God" with biotechnology. But the agricultural world is now facing another huge hurdle: how to produce enough high-quality protein.
The biggest farming challenge was in 1960, when we feared much of the world would starve before 1980. Plant breeders, using standard crossbreeding techniques, produced the green revolution and made it possible to triple the yields on the world's best cropland. As a result of that valiant effort, per capita calories in the Third World have increased by 35 percent--during the greatest surge of population growth the world will ever see.
Today the world's population growth is tapering off rapidly. The trends say we'll peak at about 8.5 billion people by 2035 or before. The average births per woman in the developing countries have already dropped from 6.5 in 1960 to about 3.1 today. Since population stability is 2.1 births, poor countries have already come more than 80 percent of the way toward stability in one generation. The First World is below replacement, at 1.7 births per woman.
Trade and technology are making the Third World more affluent, and diet quality is rising rapidly toward First World levels. The demand for meat and milk is soaring as a result. We might be able to get adequate protein from nuts and tofu, but few of us seem willing to, if we can afford meat. China's meat consumption is rising by 10 percent per year. Indonesia is clearing tropical forest to grow low-yielding corn and soybeans for chicken feed. India is stripping leaves and branches from its forests to feed 400 million dairy animals.
Less than 0.2 percent of Americans are vegans, forgoing livestock calories, and the percentages are similar in the rest of the affluent world. There may be good nutritional reasons for our passionate pursuit of meat and milk. Livestock protein is complete in amino acids and no vegetable proteins are. Livestock protein can also be digested with less energy expended per calorie. Plant foods are typically low in some key nutrients, especially calcium, iron, zinc, and vitamins D and [B.sub.12]. (That's why vegan diets can actually risk the health of infants and young people.)
Yet to save the world's wildlands by having people eat "lower on the food chain," we might need to have 80-90 percent of humanity eating vegan diets by 2030. This is extremely unlikely. There is no funding for a major global vegan campaign, let alone any historic success in convincing large numbers of people to permanently give up livestock products.
Our other alternative--and the one that has worked in the past--is using science and knowledge to raise our crop and livestock yields per acre still further. That's where biotechnology appears to be critically important.
More protein at lower cost
The Food and Drug Administration (FDA) is expected to soon approve the use of a genetically engineered copy of the hog's natural growth hormone. The biotech version of this hormone will let us produce pigs with half as much body fat and 15 percent more lean meat--using 25 percent less feed grain.
The new technology will, in effect, provide the equivalent of about 25 million tons of corn per year for hog feed--from laboratory bacteria that produce the pork growth hormone, instead of from clearing more land for crops.
Ordinarily, when a farmer gives a pig more feed than its natural supply of growth hormone can turn into muscle, the extra calories go into fat production. With the additional growth hormone (coming from a tiny capsule behind the hog's ear) the pig grows faster and leaner.
Kids in East Africa don't get much milk, in large part because of the vicious tick-borne diseases that attack the region's cattle. Farmers there lose a million cattle each year just from one tick-borne disease called East Coast fever (Thieleria parva).
Until recently, African farmers have tried to fend it off by dipping their cattle in tick-killing pesticide solutions every few weeks. But most of the farmers have to herd their cows several hours to the dipping site, so they may not dip as often as they should. And now the ticks are becoming resistant to the tick-killing chemicals.
Recently, the region has tried deliberately infecting its cattle with the disease and then immediately treating them with antibiotics. But antibiotics are exotic stuff in East Africa, and few farmers can afford them. And even when the cattle do survive, they become walking reservoirs of the disease.
Now biotechnology is letting researchers make safe vaccines by genetically copying the protein coating of the disease organism, or some other safe element of the disease's DNA. When the DNA copy is used as a vaccine, the animal's body "recognizes" it and begins to manufacture white cells and antibodies to fight off the real disease.
In this way, an international livestock disease research center in Kenya has genetically engineered a safe vaccine for East Coast fever. The vaccine is now being field-tested. If it works, it will keep more East African cattle alive and productive without the dipping vats full of pesticides or the danger of deliberately infected cattle spreading the fever.
What about using a natural genetic mutation to get more meat with fewer resources? The famous Belgian Blue double-muscled cattle are the result of a natural gene mutation noted by European farmers in the early 1800s. These cattle have nearly 20 percent more meat per pound of carcass, and it's all tender. The only drawback is that Belgian Blue calves are so heavily muscled at birth that they often have to be delivered by cesarean section.
The same gene modified in the Belgian Blue cattle exists in other cattle, in hogs, and even in poultry. Could we manipulate the gene for a somewhat less drastic increase in muscling, for a more cost-effective increase in tender meat per animal? In poultry, would a heavily muscled chick emerging from the egg be anything but a productivity gain? Genetic engineering holds out these fascinating possibilities.
Genetic engineering contains enough ethical questions to keep a philosophy department debating for a decade. However, ethicists make two major points: First, the key to ethics within biotechnology is whether the changes remove the basic nature of the creature; legless pigs--stacked like cordwood on a shelf--would be unethical. Second, the ethics of plowing down wildlife habitat are even more troubling than the ethical questions of biotechnology.
First World biotech farming
First World farmers are already using biotechnology, with American biotech companies and farmers in the lead.
The biggest impact to date has come from soybeans that tolerate herbicides with the lowest environmental impact (such as the glyphosates and sulfanylureas). This allows a farmer to suppress the weeds in his soybean fields with chemicals safe enough to be used around sensitive wild species like quail and trout. Millions of acres of herbicide-tolerant soybeans will be grown this year, mainly in the United States, Canada, and Argentina.
Farmers are also buying seed corn that contains a natural pest toxin called Bacillus thuringiensis. When corn borers start eating the stalks of the "Bt corn," they poison themselves. The first two years of field experience show that Bt corn is likely to control pests well.
Roughly 20 percent of American cows are now being given a biotech version of bovine growth hormone. The hormone improves feed efficiency about 10 percent.
English consumers are cheerfully buying cans of genetically engineered tomatoes because they are about 10 percent cheaper.
Most of the First World is eating cheese produced with the help of genetically engineered rettin. Previously, young calves had to be killed for the rettin in their stomachs.
The introduction of the first genetically engineered farm products has stimulated antitechnology activists to frenzies of media gaming:
* Environmental groups have "quarantined" test plots of bioengineered soybeans in Iowa (with yellow crime-scene tape that shows up well on TV cameras).
* Greenpeace has used its famous rubber boats to prevent ships carrying bioengineered corn and soybeans from docking in Europe.
* Greenpeace and the World Wildlife Fund have gathered more than a million petition signatures in Switzerland to ban biotechnology from food uses.
In America, consumers haven't paid much attention to the activists. In surveys, 80 percent say they are aware of biotechnology. Nearly 55 percent say that biotechnology has already provided benefits to them or their families. Nearly 80 percent say they expect biotechnology benefits in the next five years.
With such high consumer acceptance, FDA regulations on genetically engineered products are predictably mild. A food has to be labeled as genetically engineered only if it (1) introduces an allergen or (2) substantially changes the food's nutritional content or composition.
The American approach to regulating biotechnology focuses on the product not the process. That seems to make sense. The park owner in the movie Jurassic Park got into big trouble because he was breeding predatory dinosaurs. If he'd used his genetic engineers to produce a better-tasting rabbit, the failure of his electric fence wouldn't have been very dangerous.
Europe, however, has encircled biotechnology with a far more intense level of environmental and political controversy. In large part, this probably reflects Europe's history of big farm surpluses. Since the European Community (EC) was founded in 1964, it has offered its farmers high price supports--and they have responded by producing far more farm products than the EC could consume.
At the peak of the surplus problem in the late 1980s, farmers in the European Union were getting $150 billion in subsidies per year and producing 20 percent more grain, oilseeds, wine, beef, and other farm products than the member nations were willing to eat. (The surpluses were dumped at bargain prices, mostly in the Middle East and the former Soviet Union.)
Understandably, EU consumers and taxpayers aren't sure they want higher-yielding crops. But the world has no food surplus, just a surplus of farm trade barriers. And some of the trade barriers were put in place to fend off EU dumping [see "Europe's Bad Farm Policies, The World & I, April 1998, p. 64].
America also had a long bout with farm surpluses. But now, thanks to the 1996 farm bill, it is phasing out virtually all of its farm price supports and cropland diversion programs. U.S. farmers are currently aiming to supply the big food gap emerging as densely populated Asia becomes affluent. They see biotechnology as a major asset for cutting costs and raising yields.
Europe, meanwhile, is still looking at biotechnology as a needless attack on its farm policy and its small farmers. It continues to ban a variety of farm technologies.
However, 22 million small European farms have gone out of business since the EU enacted its Common Agricultural Policy. (It's hard to keep small farmers happy with their small incomes in any country that has good-paying off-farm jobs.)
The future of biotechnology in food production
It is difficult to forecast the future of biotechnology in farming, mainly because the technology is so young and its potential is so vast.
* If inserting wild-relative genes is already boosting yields in tomatoes by 50 percent and rice by 20-40 percent, it seems probable that there is major potential for using wild-relative genes in virtually every crop plant and every domestic bird and animal. This could well recapture the agricultural research momentum of the 1960s, when crop yields were rising twice as fast as today.
* Biotechnology offers real hope in the urgent drive to save the world's biodiverse wildlands. Without biotechnology, most of the wild genes would be useless to researchers, because the plants and animals carrying the wild genes can be crossbred with only close relatives. But with genetic engineering, virtually every wild gene is now a potentially vital and broadly applicable resource for helping improve the quality of our lives and achieve our conservation goals.
* Biotechnology will also radically speed up the traditional crossbreeding of plants and animals. It can eliminate the years of tedious back-crossing needed until now to take out the negative elements of a crossbreeding experiment.
* The development of aluminum-tolerant crops is a huge step forward. It means we can expect major increases in yields from tropical soils that until now have been barely adequate for subsistence farming. The tropics have hundreds of millions of acres of low-yield cropland that may now become lush with higher yields. Brazil and Zaire also have hundreds of millions of acres of acid savannas that have never been farmed; until now they have been covered with stunted brush and poor-quality grasses. High-yield crops on all this land could eliminate most of the food-production pressure on rain forests. (Third World people will still need jobs so they can buy food, instead of homesteading the rain forest.)
* Biotechnology will apparently also help reduce livestock disease losses and boost feed conversion efficiencies as the world moves from 1 billion hogs to 3 billion, and from 13 billion chickens to perhaps 50 billion. This, too, will help save wildlands.
Seizing the potential of genetic engineering
What should we do to ensure that biotechnology continues to provide progress for agriculture?
First, the affluent countries should double the current modest public investment in agricultural biotechnology. This is not a subsidy to farmers but an investment in low food costs and wildlands conservation. There should be a special focus on biotech research for the poorest countries.
Second, we certainly should eliminate farm subsidies and the accompanying farm trade barriers; they keep us from using the world's best farmland and farming systems to their fullest potential. Asia will have eight times as many people per acre of cropland as North America, and its tropical wildlands are home to a high percentage of the world's wild species. Free farm trade will encourage Asia to import some of its food rather than cut trees.
Third, we should ensure that regulators understand both the need for research safety and the environmental potential of biotech research, so that sustainable gains in yields are appropriately welcomed, not blocked.
If we do these things, then we can expect that biotechnology in agriculture will help to eliminate most of the remaining hunger in the world, even as it becomes one of our outstanding wildlife conservation triumphs.
For the author's response to our April article "Fighting Hidden Hunger," which highlights the problem of micronutrient deficiencies remaining in countries that have benefited from the green revolution, please see the Letters to the Editor section of this issue.
Dennis Avery is the director of the Center for Global Food Issues in Church, Virginia.
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|Publication:||World and I|
|Date:||May 1, 1998|
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