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Biotechnology for Sustainability

November 5, 2009
On the Tomorrow’s Table blog, Kent J. Bradford, Professor of Plant Sciences and Academic Director of the Seed Biotechnology Center at UC Davis, serves as guest blogger and takes issue with the Center for Urban Education about Sustainable Agriculture (CUESA), an organization that manages the Ferry Plaza Farmers Market in San Francisco.

Specifically, Bradford says CUESA developed sustainable agriculture guidelines which include build and conserve soil fertility, conserve water and protect water quality, protect air quality, minimize use of toxics, conserve energy, use renewable resources, maximize diversity and conserve genetic resources.
“I'm sure every farmer would agree with them wholeheartedly…

“Then I read the last point on their list: ‘Avoid the intentional use of genetically modified seeds and organisms.’ The basis for this was apparently assumed to be self-evident, as no reasons were given for including this point in their list. To be clear, all crops have been genetically modified from their wild versions through domestication and breeding, but no doubt CUESA was referring to genetic engineering, where genes (pieces of DNA) are grafted into the chromosomes of a plant to give them specific traits. A blanket ban on genetically engineered (GE) crops implies that they are incompatible with agricultural sustainability. Let's check the facts:


Conserve soil and energy and protect air and water quality. The most popular GE crops are immune to herbicides used to kill weeds. Eliminating the need for repeated plowing to control weeds has encouraged the adoption of minimum tillage practices by farmers, which reduces soil erosion and fuel use. Consequently, GE crops cut greenhouse gas emissions by the equivalent of taking over 6 million cars off the road in 2006. And less eroded soil and fertilizer in waterways improves water quality. Check.

Minimize use of toxics. The most popular herbicide used with the GE crops mentioned above replaces others that are three times as toxic and persist twice as long in the environment. Another major GE trait is insect resistance conferred by Bt proteins from a bacterium that deter or kill specific groups of worms that eat crops. In its sprayed form, Bt is approved for organic crops. In its GE crop form, it reduced global insecticide use by 300 million pounds between 1996 and 2006 (a 30% reduction). Check.

Conserve water. Water shortages and high salinity are two of the biggest threats to the sustainability of agriculture in California, particularly if climate change reduces rain and snowfall, as is predicted. My colleague at UC Davis, Eduardo Blumwald, has used genetic engineering to develop plants that can maintain yields with less water and can thrive on salty water that would kill most crop plants. These traits clearly will contribute to sustaining agriculture with less water, not only here, but also in agricultural lands around the world that are threatened by drought and salinity. Check.

Conserve soil fertility and natural resources. Research at Arcadia Biosciences right here in Davis promises to allow crops to produce the same yields with only one-third as much fertilizer. This would conserve natural gas used to make fertilizer and reduce nitrogen runoff from fields. Check.

Conserve biodiversity and genetic resources. The best way to promote biodiversity is to preserve native habitats. By maintaining and increasing yields on existing farms, GE crops help to minimize expansion of agriculture into natural areas. Check. 
“A recent comprehensive study by the Keystone Center examined five criteria for sustainability (energy use, soil loss, irrigation water use, climate impact, and land use) and found that corn, cotton, and soybeans all improved between 1997 and 2007, a period during which GE varieties became dominant in these crops. In contrast, wheat, which has no commercial GE varieties, showed little or no improvement in sustainability indices over this period.

“These results from 13 years of commercial GE crops are clear: if CUESA and other groups are serious about advancing agricultural sustainability, they should encourage producers to use GE crops rather than avoid them. And if they want to educate urban consumers about sustainable agriculture, there is a great story to tell about biotechnology FOR sustainability.”