DES MOINES, Iowa – While warmer average temperatures can have a dramatic impact in colder climates, new research shows how much crop growth can be affected when temperatures change by just a few degrees Celsius.  For Iowa, one crop that would be affected drastically is corn. The research, headed by Michelle Tigchelaar, a postdoctoral researcher at the University of Washington, shows that an increase in average temperature of two to four degrees Celsius would decrease crop yields by at least 18 percent across the United States.

Tigchelaar said the range of the temperature increase will be a large determinant of the scale of crop failures. “So, with 2 degrees of warming, the effects are severe but somewhat, you know, manageable,” Tigchelaar said. “But with 4 degrees of warming, it becomes really sort of something that we haven’t quite seen before.” In Fahrenheit, those temperature differences are from 3.6 to 7.2 degrees warmer.

The study looked at crop yield effects around the globe, including countries such as China and Brazil, observing weather patterns and corn yields. An 18 percent decrease in crop yields would mean an Iowa farmer expecting 175 bushels of corn per acre would bring in only about 144 bushels. That would have a large impact on other products such as corn syrup and meat.  Environmentally friendly structural changes and crop adaption to higher temperatures are all possibilities for limiting the damage of a warmer climate. But for farmers, Tigchelarr said environmental changes are just some of the ongoing obstacles. “They deal with changes in their environment regularly, so to some degree you can adapt your farming practices by planting on different dates, or planting a slightly different variety,” she said.

Some scientists expect the development of biotechnology and farm management to allow corn to grow as normal, despite climate changes.

(Iowa News Service)