Large amounts of herbicides and chemical nitrogen fertilizers are not necessary for a profitable modern farm. Going back to the future by rotating crops more and grazing cattle in pastures instead of confining them in buildings can also mean less water pollution.
These are the conclusions of research conducted by scientists at Iowa State University and the U.S. Department of Agriculture and published recently in the scientific journal PloS One. From 2003 to 2011, the researchers examined a farm in Boone County, Iowa, called the Marsden Farm. They found that increasing the diversity of crops in rotation on a farm (adding, for example, alfalfa and clover to the usual annual rotation of corn and soybeans) and using the manure from grazing cattle can reduce the amount of synthetic nitrogen fertilizer required by 80 percent and cut the amount of herbicides needed to keep weeds down by 88 percent. Moreover, the levels of herbicides in nearby waterways were 200 times lower, according to Iowa State.
Crop yields were also slightly higher, compared to a conventional two year rotation of corn and soybeans treated with chemicals, according to the researchers.
Karen Stillerman, a senior analyst with the Union of Concerned Scientists, wrote in an article that these conclusions showing the value of “low input” agriculture (meaning, farming without lots of chemicals) conflict with the financial interests of big fertilizer and chemical companies that try to convince farmers that they must practice “high input” farming to survive financially.
“There’s very little for big corporations to sell to farmers who are engaged in low-input agriculture,” Stillerman wrote. “In fact, just the opposite—the more farmers are convinced they can’t be profitable without pricey inputs, the better the companies’ bottom lines will look. Even when it just isn’t true.”
Mark Bittman, a columnist for The New York Times, wrote that the Iowa study demonstrates that “chemicals contributing to ‘environmental externalities’ (also known as pollution) can be drastically reduced at no sacrifice, except to that of the bottom line of chemical companies.”
What is your bottom line on this?
By Tom Pelton
Chesapeake Bay Foundation
(Photo at top by CBF)