Wind turbines cover rural Iowa, offering corn and soybean farmers an additional source of income. But how do those giant spinning blades affect crops?
So far Agronomist Gene Takle of Iowa State University says his multiple studies haven’t found that turbines effect crop yield. But that doesn’t mean they don’t impact the conditions on a field.
In a recent study published in the Journal of Geophysical Research, Takle documented that the temperature around two turbines dropped by as much as a degree when they were powered down for a little over an hour for nighttime maintenance.
"The motions of the air over the blades create turbulence, and the turbulence spreads in a wake downwind of the turbine," he says.
And this wake creates a drying effect, which is warming. Hence the reason that when the turbines are off at night, it’s slightly cooler.
Takle adds turbines may also have minor effects on moisture and carbon dioxide levels.