Crop scientists: Climate changes may be good for corn, beans for a while

Projected climate changes in Iowa should prove beneficial to the production of corn and soybeans, leading agricultural scientists say.

“The impact on agriculture in the Upper Midwest, at least through 2050, is probably net positive,” said David Gustafson, one of 25 Monsanto scientists who took “a deep, hard look” at all the publicly available scientific climate data two years ago.

“Yes, there are questions and speculation, but overall, yes, the climate is changing,” Gustafson said.

Unlike partisans in the political debate over climate change, crop scientists operate on a straightforward and transparent agenda - ensuring their companies can produce plants that will flourish in whatever climactic conditions prevail. The nourishment of billions of future Earthlings, not to mention the well-being of their multibillion-dollar for-profit companies, depends upon their being right.

The good news, the Monsanto scientists told the company's board of directors, is that the change is gradual and the company is well-positioned to take advantage of it, Gustafson said.

Asked to characterize changes for the Upper Midwest, Gustafson said the trends indicate more precipitation and a longer growing season.

During the latter half of the century, as the climate continues to warm, heat stress could offset some of the earlier climate change gains, he said.

Pioneer Hi-bred scientist Jeff Schussler, a member of a company committee studying global climate change, said he and his colleagues also have identified trends that favor increased corn and soybean production in the near term.

Along with increased precipitation in the Upper Midwest, Pioneer scientists “have seen evidence of a trend toward longer growing seasons” with higher average temperatures, Schussler said.

Schussler and Gustafson said increasing concentrations of carbon dioxide in the atmosphere - widely believed to be the root cause of global warming - also favor increased crop yields.

While there is “a slight positive response for corn, soybeans and wheat will respond very nicely to increased carbon dioxide in the air,” Schussler said.

As generations of Iowa farmers have known, “rain makes grain,” and the outlook for more rain bodes well for Iowa farmers - up to a certain point, said Elwynn Taylor, professor of ag meteorology at Iowa State University.

“Everyone is in agreement: There has been a 10 percent increase in annual precipitation in most of the Corn Belt since 1950 - a trend that is likely to continue,” Taylor said.

Given that the largest-single limiting factor in corn production is stress caused by the lack of rainfall, crops will likely be better because of fewer summer dry spells, he said.

All is not rosy in that scenario, Taylor cautioned. Increased precipitation causes increased runoff, which can, as it did in much of Iowa in 2008, inundate farm fields. In most years, yield gains attributable to ample rainfall will outweigh losses caused by flooded fields, he said.

Taylor said precipitation increases already have shifted the Corn Belt markedly westward during the past 30 years.

Corn production has increased dramatically in eastern portions of Nebraska and South Dakota, and productivity gains in western Iowa have made that region competitive with the historically superior corn production of Eastern Iowa, Taylor said.

Monsanto's Gustafson said the Corn Belt could shift 50 to 100 miles northward in the next 20 years, if predicted temperature increases materialize.

Taylor said a doubling of carbon dioxide concentration in the atmosphere, predicted to occur in the next 40 to 60 years, would yield a general warming of 5 degrees Fahrenheit.

Warmth and moisture benefit crops “until you get too much” - a scenario that is likely to occur more frequently after midcentury, said Taylor, who speaks to thousands of farmers each year.

“They all know the climate is changing,” he said.