The great ecological win with GE herbicide-tolerant crops is that they encourage what is called no-till agriculture. Farmers don’t have to plow. The stubble from last year’s crop rots in the field, turning into compost and habitat for small wildlife, and the soil is held in place instead of eroding away. Farmers employ a method called direct seeding to inject seeds, each with a shot of fertilizer, into the soil through the stubble; then, just when their crops begin to emerge, they spray the field with glyphosate and wipe out all the weeds with no effect on the glyphosate-tolerant crop plants. The result is a high-yield crop and intact soil that grows in richness from year to year, full of life, with a lovely crumb structure. “With no-till,” says Jim Cook, a plant pathologist and sustainable-agriculture evangelist at Washington State University, “you improve soil structures, stop erosion, sequester carbon, improve water filtration rather than letting it run off the land, and store more water in years of drought.”
There are also major climate benefits. Soil holds more carbon in it than all living vegetation and the atmosphere put together. (Earth’s soil holds about 1,500 gigatons of carbon, versus 600 gigatons in living plants and 830 gigatons in the atmosphere.) Tilling releases that carbon. Jim Cook explains: “Carbon disappears faster if you stir the soil. If you chop the crop residue up, bury it, and stir it—which is what we call tillage—there’s a burst of biological activity, since you keep making new surface area to be attacked by the decomposers. You’re not sequestering carbon anymore, you’re basically burning up the whole season’s residue.”
Plowed land is the source of gigatons of carbon dioxide in the atmosphere. Cultivated soil loses half of its organic carbon over decades of plowing, but sustained no-till farming can bring the carbon content back to a level the equal of wildland soil, such as in tallgrass prairies, according to soil microbiologist Charles Rice, who has done extensive comparative studies at Kansas State University. More and more of GE agriculture is shifting to no-till—80 percent of soybean acreage, for example—because it saves the farmer so much time, money, and fuel. Saving the fuel also helps save the atmosphere. “About 5 percent of all fossil fuel use is by agriculture, and most of this goes on weed control,” writes geneticist Jennifer Thomson in Seeds for the Future.
Organic farmer Raoul Adamchak told me that the GE farmers he met at a no-till meeting in California are starting to sound like organic enthusiasts, bragging about the richness of their soil and counting their earthworms. Organic farmers, however, can’t use GE, so they continue to plow every spring, burying the cover crops and early weeds, releasing the soil’s carbon dioxide. (Some organic farmers are aware of the problem but haven’t yet found a non-GE solution.)
• One very proper subject for criticism of any new kind of crop is how well or badly it fits in with the local ecology—the agroecology, as we say now. This is where the subject of “superweeds” comes up. It’s a familiar aggravation for farmers. Weeds adapt quickly to exploit the sunlit, watered, fertilized luxuries of cropland and find it easy to compete with the coddled crop species if they can just dodge around the farmers’ countermeasures. Some weeds, if they’re related to the crop plants, may borrow helpful genes from them. That has happened historically with rice, millet, sorghum, sunflowers, and sugar beets, and it is legitimately something to worry about with new GE crop genes.
New glyphosate-resistant weeds are turning up, not so much through gene borrowing as through the usual evolutionary response to the increased selection pressure of any highly successful, overemployed, deadly technique. When only glyphosate is used to kill weeds, some weeds will evolve a workaround all too soon. The main countermeasure is to employ the full arsenal of integrated pest management—crop timing, crop rotation, biocontrols, etc.—so the weeds face too many simultaneous obstacles to evolve around. Genetic engineering also can “stack” genes for resistance to other effective herbicides such as Dicamba along with the glyphosate resistance, and the genes can be parked in the maternal portion of the genome so they can’t spread to the world through the male pollen. Such seeds are in the pipeline. GE is just another tool in the ever-evolving integrated pest management kit.
Agricultural weeds specialize in threatening farmers, not the wildlands. A glyphosate-resistant weed in the anything-goes combat of the woods is like a boxer in a gunfight—wrong skills for the situation.
• What about superbugs? Here the questions are raised around the hugely popular engineered crops Bt corn and Bt cotton. The Bt stands for Bacillus thuringiensis, a common soil bacterium with a unique toxin lethal to the larvae of the butterflies and moths that normally feed on the now-GE crops. Organic farmers have long sprayed dried Bt bacteria on their crops because they are considered a natural pesticide; they are very effective; and they kill only the target insects, with no harm to beneficial insects or human customers. When the bacterial gene that makes the Bt toxin was engineered into corn and cotton, the transgenic plants were able to kill the pests by themselves: no spray necessary. Furthermore, because the toxin is in the plant, even spray-eluding corn borers are defeated. (That’s why ears of organic corn usually have a live corn earworm in them. Bt corn is forbidden to organic farmers, so most sell no corn at all.)
The main ecological effect of Bt crops has been a drastic reduction in pesticide use. Cotton is especially pesticide-intensive. The introduction of GE cotton has dropped pesticide use by half. In one GE crop region studied, a tenth as many farmworkers are being hospitalized for ailments caused by farm chemicals. And, astonishingly, no insect pests significantly resistant to Bt crops have evolved yet, even though some five hundred insect species have developed resistance to sprayed pesticides.
Thus GE crops help mitigate greenhouse gases and are more ecologically benign than non-GE crops. “GM corn, cotton and soybean have been in commercial use for over five years now, and millions of hectares have been grown without any field reports of adverse ecological impacts,” said a 2001 study in the peer-reviewed journal EMBO Reports. “Substantial environmental benefits,” it continued, “have been established for some of these products, such as Bt cotton, because of the resulting reduction in the use of chemical insecticides. . . . Indeed, populations of predatory arthropods that help to control secondary pests like aphids are found to be consistently higher in Bt cotton fields than in sprayed fields of conventional cotton.”
Peter Raven sums it up: “To assert that GM techniques are a threat to biodiversity is to state the exact opposite of the truth. They and other methods and techniques must be used, and used aggressively, to help build sustainable and productive, low-input agricultural systems . . . around the world.”
Many environmentalists argue that genetically engineered crops threaten the “family farm.” The argument requires maintaining two illusions—one nostalgic, the other economic and political, both illusory because of historical forces that have nothing to do with GE.
The family farm idea is a bucolic fantasy based on selective memory, songs from musicals (“Howdy, neighbor! Happy harvest!”), and the marketing images used for organic produce. It recalls what the world was like in 1900, when half of all Americans lived and worked on farms. One percent of Americans now work on farms. You can’t have a family farm if all the children light out for the city, and that’s what they do. The average age of American farmers is fifty-five.
Government has tried to keep people down on the farm with an elaborate system of subsidies—some of them, perversely, supporting bad farming. Since rural values are by and large conservative values, you get the farce of conservative politicians legislating huge government subsidies and conservative farmers sitting in dying towns grumbling over coffee about the dole they’re on.
The reality of farmwork is that it is the lowest-paid labor there is, and most of it is backbreaking. In the developing world, the toil is done largely by unpaid family members, mostly women, hacking away with hoes at the weeds in the tomato fields all day every day, or bent over in the rice paddies hand-planting seedlings in th
e muck. In the developed world we hire immigrant laborers to do it.
Environmentalists keep insisting that GE crops are bad for farmers, especially small-scale farmers. That position is tough to maintain as the reality emerges that even in the face of opposition, GE crops are tremendously popular. “Every time a GE crop has been approved for use,” notes Pamela Ronald, “farmers have embraced it and the GE acreage for each crop has quickly grown to 50 to 90 percent of the total acreage.” A 2008 study funded by the Rockefeller Foundation reported:Two million more farmers planted biotech crops last year, to total 12 million farmers globally enjoying the advantages from the improved technology. Notably, 9 out of 10, or 11 million of the benefiting farmers, were resource-poor farmers. . . . In fact, the number of developing countries (12) planting biotech crops surpassed the number of industrialized countries (11), and the growth rate in the developing world was three times that of industrialized nations (21 percent compared to 6 percent).
In the developing world, nearly all farms are smaller than five acres, and most are one acre or less.
• Farmers want GE technology for their crops; nonfarmers want them not to want it. I’ve seen a classic case of that standoff play out between Marin and Sonoma counties in California. Our tugboat home is in nonagricultural Marin, close to San Francisco and its attitudes. Marin outlawed GE agriculture in 2002. The defunct dairy farm where we spend weekends is in Sonoma, the next county to the north, still primarily agricultural. In 2005 Sonoma voted on an ordinance to abate all GE agriculture in the county. The official argument for the measure evoked the standard language: “Measure M will protect Sonoma County’s family farmers, gardeners and environment from irreversible genetic contamination by GE organisms. Our children should not be used as guinea pigs for genetic engineering. When GE crops are released, they create herbicide-resistant superweeds and contaminate the local food supply and natural environment. Genetic contamination is forever—it can’t be recalled, contained or cleaned up.”
Nine local farmers’ organizations, including the Sonoma Country Farm Bureau, opposed the ban. “In contrast,” Pamela Ronald notes, “urban residents, food processing companies, and wineries support[ed] it, hopeful to include ‘GE-free Sonoma’ on their label, as a new way to market their products.” They lost: Measure M was defeated, 55 percent to 45 percent. Wherever farmers rule, GE wins. All the major agricultural counties in the state defeated similar resolutions.
In 2006, when two hundred French anti-GE activists destroyed fifteen acres of GE corn near Toulouse, eight hundred local farmers marched in a nearby town to protest the attack and petition the government to support GE research. In 2000, GE soybeans were legal in Argentina but outlawed in Brazil. The difference in productivity was so obvious that Brazilian farmers smuggled the seeds across the border, until their government relented and legalized GE agriculture.
• Why do environmentalists want to deny the advantages of GE crops to farmers in the developing world, who need it most? Robert Paarlberg, author of Starved for Science: How Biotechnology Is Being Kept Out of Africa (2008), theorizes that rich countries have the luxury of debating the nuances of economics and perceived risk around GE crops, whereas poor countries don’t:The technology is directly beneficial to only a tiny number of citizens in rich countries—soybean farmers, corn farmers, a few seed companies, patent holders. Consumers don’t get a direct benefit at all, so it doesn’t cost them anything to drive it off the market with regulations. The problem comes when the regulatory systems created in rich countries are then exported to regions like Africa, where two thirds of the people are farmers, and where they would be the direct beneficiaries.
Florence Wambugu puts it baldly: “You people in the developed world are certainly free to debate the merits of genetically modified foods, but can we please eat first?” (A Kenyan plant pathologist educated on three continents, Dr. Wambugu did a three-year postdoc in genetic engineering with Monsanto, developing a virus-resistant GE sweet potato. She heads the Africa Harvest Biotech Foundation, based in Nairobi. In 2008 she won the Yara Prize for a Green Revolution in Africa.)
Poor farmers in the developing world take to GE seeds as readily as they take to cellphones, as a direct route out of poverty. The combination allows them to sell food to the new urban populations at urban prices and escape the cashless trap of subsistence farming. A similar flip happens at the national level. When, despite fierce lobbying by Indian pesticide companies, farmers in India adopted Bt cotton in 2002, the nation went from a cotton importer to an exporter, from a crop of 17 million bales to 27 million bales. What was the social cost of that? The 2008 Rockefeller-funded report says:A study of 9,300 Bt cotton and non-Bt cotton-growing households in India indicated that women and children in Bt cotton households have slightly more access to social benefits than non-Bt cotton growers. These include slight increases in pre-natal visits, assistance with at-home births, higher school enrollment for children and a higher proportion of children vaccinated.
The main event was that Bt cotton increased yield by 50 percent and diminished pesticide use by 50 percent, and the Indian growers’ total income went from $840 million to $1.7 billion.
• Activists have been unable to persuade farmers that GE crops are bad for them because the farmers’ direct experience tells them otherwise. So the activists focus instead on undermining the farmers’ market by frightening their customers, the general public, with phantasms of genetic “contamination.”
There are vivid stories that anti-GE people repeatedly tell each other—and anybody who will listen—to keep themselves reassured that their cause is just and their passion necessary. The stories become legend—the one about the monarch butterflies, the one about native Mexican corn, the one about the “terminator gene.” On the other side, people who promote GE have their own tales: the papaya story, the “golden rice” story, the Zimbabwe poison story. They all have basis in fact, but in each case, important information is left out of the legend, especially the then-what-happened part. Pursued down to detail level, the stories shed a different light. Let’s peruse.
BT CORN POLLEN KILLS MONARCH BUTTERFLIES
The story: A May 1999 issue of Nature included a one-page note—“Transgenic Pollen Harms Monarch Larvae”—by Cornell entomologist John Losey and colleagues. They reported a four-day lab experiment in which monarch caterpillars were fed an unspecified amount of pollen from Bt corn, and 44 percent of them died. The story made the front page of the New York Times and was broadcast widely by GE opponents. It still is.
The rest of the story: Subsequent exhaustive field research showed that the actual effect of Bt corn pollen would kill, at most, three monarch caterpillars out of ten thousand, a minute fraction of the hazards monarchs face from other impacts of civilization. Six detailed papers on the subject (with thirty authors) appeared in the Proceedings of the National Academy of Sciences (PNAS) in September 2001 but got no secondary press because their news was lost in the media din created by 9/11. Superenvironmentalist Peter Raven cowrote a July 2000 paper in PNAS, which concluded that, because the major real harm to monarch populations is from habitat loss and the use of pesticides in Mexico and the United States, and “considering the gains obviously achieved in the level of survival of populations of monarch butterflies and other insects by eliminating a large proportion of the pesticides applied to the same crops, the widespread cultivation of Bt corn may have huge benefits for monarch butterfly survival.”
(Monarchs are bright orange for an interesting coevolutionary reason. The larvae feed on milkweeds, having developed the talent to endure the poison, a cardiac glycoside, with which the plants repel most other bugs. The monarch caterpillars not only tolerate the poison, they incorporate it into their brightly colored bodies and pass it on to their brightly colored, slow-flying adult form. The brilliant colors are advertising: “I’m really poisonous!” Birds learn to shun monarchs. Another somewhat poisonous butterfly, the viceroy, which gets its poison from eating willow leaves, a
dapted to look exactly like the monarch so that birds would efficiently lump all vile-tasting prey into a single orange avoidance image. It’s one of the classic just-so stories of coevolution. The concept of coevolution, by the way, was coinvented in 1964 by botanist Peter Raven and lepidopterist Paul Ehrlich—before his population bomb fame. Their paper, “Butterflies and Plants: A Study in Coevolution,” is one of the most cited in biology. When Peter Raven says Bt corn is good for monarchs, he probably knows what he’s talking about.)
GENETIC POLLUTION: BIOTECH CORN INVADES MEXICO
The story: In November 2001, Nature published “Transgenic DNA Introgressed into Traditional Maize Landraces in Oaxaca, Mexico,” by David Quist and Ignacio Chapela. The paper’s impact was immediate and widespread, because landraces are important to agriculture. They are reservoirs of genetic diversity, maintained by traditional, small-scale farmers who save and select their seeds for optimization to local tastes and local conditions. Particularly worrisome is anything suspicious happening with corn landraces in Mexico, where the crop was first created and first diversified; landraces comprise two thirds of all the corn grown in Mexico.
The Nature paper suggested that genes and gene fragments from GE corn were turning up in landrace genomes, uninvited and through untraceable pathways. “This is the world’s worst case of contamination by genetically modified material because it happened in the place of origin of a major crop,” said Jorge Soberón, secretary of Mexico’s National Biodiversity Council. “It was as if someone had gone to the United Kingdom and started replacing the stained-glass windows in the cathedrals with plastic.”
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