Hope for sustainable farming in gene-altered crops
September 4, 2001
by Dennis T. Avery
Genetically engineered crops are poised to give human society its biggest sustainability gain in almost 100 years. Research at the University of California at Davis has produced a new gene-altered tomato that not only grows in salt water - but also desalinates the soil in which it grows.
This is just in time to counter what Science News magazine calls an "agricultural nightmare" - the worldwide salinization of irrigated croplands. Currently, irrigated lands grow 30 percent of the world's food, but we're losing millions of these scarce and irreplaceable acres annually to the buildup of salts. (There are salts in all water and soils. Until now, the only way to flush out the salts took lots of water and major investments in canals and drains.)
The salt buildup in irrigated croplands long has been the green movement's most realistic argument that modern farming was unsustain-able. But that argument is now gone. Eduardo Blumwald and a colleague at UC Davis modified their tomato plants to produce more of a natural plant protein that causes the plant to filter out salts taken up by its roots, and store the salt in its leaves. "In order to get that plant to be tolerant of salt, you have to make that plant over-express its own gene," he says. Many of nature's own salt-tolerant plants (such as marsh grasses) deal with salt this way.
The new plants have successfully passed their salt-solving transformation on to their offspring in test plots. They must still undergo safety tests, but this advance is a matter of turning up a natural gene that exists in most plants, not adding a poten-tial new allergen or pesticide from another organism.
"You can grow this plant at the same height and the same number of fruits and the same quality of the fruits as normal plants [even] when you water them with the equivalent of 40 percent seawater," Dr. Blumwald says. He believes we can activate genes that already exist in all major food crops, to make them as salt-tolerant and salt-removing as the tomatoes.
This breakthrough will make the world's irrigated lands permanently sustainable. It will also salt-proof the food production in such major irrigating countries as China, India, and Indonesia, as well as in such poverty-ridden countries as Iraq and Yemen.
Salinization is costing the world 10 Yellowstone National Parks' worth of wildlife habitat annually. Each year for decades, the world has been losing nearly 5 million to 7 million acres of these scarce and irreplaceable lands to salt buildup - and each acre of irrigated land produces three times as much food as the average nonirrigated acre.
For at least 100 years, plant breeders have tried to cross conventional crop plants with salt-tolerant ones, with virtually no success. But Dr. Blumwald says he's already got both tomatoes and canola plants flourishing in 40 percent seawater. Since the canola plants are tall, with lots of leaves, they remove 12 grams of salt per plant.
The desalinating-tomato breakthrough should be important proof for the world's consumers and governments that biotech is agriculture's most important 21st-century tool. It will help farmers grow the additional food crops the world wants and needs - through higher yields on the land they're already farming. Biotech opponents claim that bioengineered crops help only big corpo-rations.
The UC Davis research on desali-nating crops proves these critics massively wrong. It also proves that if we aren't comfortable with big corporations doing all the biotech crop research, we can productively increase funding for public research.
Instead, the green movement has been demanding no agricultural research at all. The activists prefer an organic retreat to the famines and worn-out farms of the 19th century. Back then, of course, we could cut down virgin forests and get enough additional cropland to cover traditional farming's shortcomings.
The last comparable step in human sustainability was the Haber-Bosch process, developed in 1909, which allows us to get nitrogen fertilizer from the air. (Both Fritz Haber and Carl Bosch worked for a private company, and won Nobel Prizes.) Without their fertilizer, we'd have long since cleared all of the world's existing forests, to pasture 10 million cattle instead of 1.3 million, so we'd have enough manure to fertilize current food production.
Biotechnology is already demonstrating such power in agriculture that by 2050 it may ensure fully sustainable grain and meat production for the world's projected peak population of 9 billion people - without taking any more land from nature. How many Nobel Prizes should that be worth?
Dennis T. Avery is based in Churchville, VA, and is director of the Hudson Institute's Center for Global Food Issues.