Wind turbines may boost crop growth

Wind turbines in farms not only capture renewable energy, but may also help crops grow more efficiently, a new study has found.
Tall wind turbines disbursed throughout a field create air turbulence that may help plants by affecting variables such as temperature and carbon dioxide concentrations, said Gene Takle, a professor at Iowa State University in the US.
Scientists installed research towers on a 200-turbine wind farm. The research towers collected data from 2010 to 2013 on wind speeds and directions, temperature, humidity, turbulence, gas content and precipitation.
The project aimed to discover how the turbulence created when wind moves through the turbines affects conditions at ground level where crops grow.

The data show that the wind turbines have a measurable impact on several key variables that affect growing conditions.
It is more difficult to pin down whether those changes affect crop performance, but Takle said wind turbines may make growing conditions more favorable for corn and soybeans.

"On balance, it seems turbines have a small, positive impact on crops," he said.
Takle said turbines can change the temperature in the areas around them. The data show that turbulence produced by wind turbines leads to temperatures about a half degree cooler during the day and between a half to a full degree warmer at night.

That is because the turbulence mixes air at different elevations. That mixing cools the ground level during the daylight hours, like a fan blowing on a wet surface, Takle said.
At night, as the ground loses heat, the mixing brings warmer air aloft down to ground level, resulting in a net warming effect.
The turbulence also suppresses the formation of dew and dries the crops, Takle said, which could combat harmful molds and fungi.
The turbulence, and the associated changes in air pressure at ground level, also may enrich the carbon dioxide content in the air surrounding crops, which could make the plants grow more efficiently, he said.