Genetically modified agriculture holds both the promise of drought- and virus-resistant crops and the peril of unraveling the natural food chain. But like it or not, it's one genie that's already out of the bottle.
Instead of GE and chemicals, Liebman advocates the "many little hammers" approach--employing varied management methods that together control weeds. This might mean rotating diverse crops, planting cover crops that suppress weeds and bolster soil health, limiting tilling to prevent erosion, and applying sparing amounts of pesticides. "It's not a panacea," he says. "If you use a range of tactics, each of them is relatively weak, but cumulatively they're strong. It works, but it requires more management."
Whether Big Ag would adopt the approach is another matter. "We have a whole bunch of pesticides that work," Liebman says. "They're convenient, and farmers will start using those in sequence." As with glyphosate, resistance will crop up, he says. Some weeds already tolerate multiple herbicides, which might lead companies to stack resistance to several herbicides. Asks Liebman, "The question is, do you want to be on that pesticide treadmill forever?"
Monsanto has no intention of getting off the treadmill, but it is diversifying, as a visit to its facility outside St. Louis makes clear. In a sticky-warm sixth-floor greenhouse, dozens of potted, four-foot-high corn plants sit in neat rows. A sign on one wilted stalk reads: "Do not water." These plants are being developed for drought tolerance. Their more advanced predecessors are being field-tested on the western Great Plains. Mark Lawson, head of yield and stress traits research, says that as climate change causes arid regions to become even drier, it could become an important crop here and in sub-Saharan Africa, where the company, with funding from the Gates Foundation and the Howard G. Buffett Foundation, is developing drought-tolerant corn hybrids.
Monsanto expects to introduce the product to U.S. markets after trials in 2012. It's something farmer Hartman has been waiting for. "I'd love to try it on the drier pieces of land. It seems like every year they say it's one year away." The delay shows how tricky this particular aim is. "Drought is the most complex trait you can work on," says Lawson. The crop has to grow well under arid conditions but also produce adequate yields in rainy years. And testing for unintended side effects--like increased disease susceptibility--takes years.
Gurian-Sherman, meanwhile, favors looking to conventional breeding for drought-tolerant corn. In fact, such products are expected to hit the market around the same time as Monsanto's. It's too early to say which will win out, but there's a lot of money at stake: Analysts say the drought-tolerant-corn market may top $2.7 billion.
Such crops are just one example of the new directions corporations, governments, and academics are pushing genetic engineering. Not all the products will make it to market, but some certainly will. At the same time, the public backlash against GE isn't dying down, as demonstrations against GE salmon show. With so much in motion, Mortensen would like to see broader, science-based discussions that weigh the risks and benefits. "In the end, I probably won't be on board supporting a lot of genetically engineered crops with stacked resistance," he says. "But I would really love to see us take a step back and see if this is the best way to go."