'Thought for food' chews on conservation agriculture

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Blogger Nathanael Johnson, who writes 'Thought for food' on the Grist website, recently contemplated the impacts of reduced soil tillage on the use of chemical herbicides and crops genetically engineered to tolerate herbicide applications.

He noted that the practice of tillage in farming does not mimic nature.

"Nature only rarely turns the land upside down — only during disasters," Johnson wrote. "This ecosystem (soil) responds to being turned upside-down the same way a rainforest would: It falls apart."

However, the author wondered whether the development of herbicide-tolerant crops has led farmers to adopt conservation tillage. For an answer, he turned to Jeff Mitchell, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis.

“I’ve heard farmers here in California say that Roundup resistant crops effectively allowed some people to start doing conservation tillage,” Mitchell said. “But you have to remember, the vast majority of farmers in the U.S. using Roundup Ready seed don’t do conservation tillage.”

Garrison Sposito, professor in the Department of Environmental Science, Policy and Management at UC Berkeley, said genetically modified crops and herbicide use aren't required for conservation agriculture, but without them, yields go down.

"You never solve problems by making changes,” Sposito said. “What you do by making changes is exchange one set of problems for another set of problems.”

Have GMOs triggered conservation-minded agriculture? In the U.S., just a little bit, Johnson concluded.