Crops Benefit from Wind Turbines
The wakes may fend off disease, aid CO2 extraction
For years the economic benefits of wind turbines on farms have been limited to discussions about lease payments. Now, a new study seems to indicate the presence of spinning blades has the added economic benefit of better crop yields.
The blades that might also help corn and soybean crops stay cooler and drier, help them fend off fungal infestations and improve their ability to extract growth-enhancing carbon dioxide from the air and soil, according to this study.
The preliminary findings of a months-long study were recently presented at the annual fall meeting of the American Geophysical Union in San Francisco. The presentation was made by researcher Gene Takle of the U.S. Department of Energy's Ames Laboratory and Julie Lundquist, assistant professor in the University of Colorado at Boulder's atmospheric and oceanic studies department.
"We've finished the first phase of our research, and we're confident that wind turbines do produce measureable effects on the microclimate near crops," Takle said. He is also the director of the Climate Science Program at Iowa State University.
According to Takle, turbine blades channel air downward, in effect bathing the crops below with the increased airflow they create.
"Our laser instrument could detect a beautiful plume of increased turbulence that persisted even a quarter-mile downwind of a turbine," Lundquist said.
Lundquist's team uses a specialized laser known as lidar to measure winds and turbulence from near the Earth's surface to well above the uppermost tip of a turbine blade.
Both Lundquist and Takle stressed their early findings have yet to definitively establish whether or not wind turbines are beneficial to the health and yield potential of soybeans and corn planted nearby. However, their finding that the turbines increase airflow over surrounding crops suggests this is a realistic possibility.
"Because wind turbines generate turbulence and the mixing of air downwind, they may accelerate the natural exchange processes between crops and the lower part of the atmosphere," said Lundquist.
For example, the sun warms crops and some of that heat is given off to the atmosphere. Extra air turbulence likely speeds up this heat exchange, so crops may stay slightly cooler on hot days, Lundquist said. On cold nights, the turbulence created by the wind turbines stirs the lower atmosphere and keeps nighttime temperatures around the crops warmer.
"In both the spring and in the fall, we suspect that turbines' effects are beneficial by warming and perhaps preventing a frost, thus extending the growing season," said Lundquist.
Wind turbines also may have positive effects on crop moisture levels. Extra turbulence may help dry the dew that settles on plants, minimizing the amount of time fungi and toxins can grow on plant leaves. Additionally, drier crops at harvest help farmers reduce the cost of artificially drying corn or soybeans.
Another potential benefit to crops is that increased airflows could enable corn and soybean plants to more readily extract CO2, a needed fuel for crops, from the atmosphere and the soil, thus helping the crops' ability to perform photosynthesis.
The CU-Boulder and ISU teams hope to continue their measurements throughout the next growing season.
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Comments
Fans for warming
In florida in years past many Citrus Groves had large motor driver propellers spaced around the grove to help protect the Groves from Freezing and frost during spring. The logic was simple and proven. On clear, windless nights when it was cool the trees would radiate IR energy (heat) into space. Through this radiation the trees and leaves would be several degrees colder than the surrounding air. The big fans kept the air circulating and the tree at air temperature. This approach worked as long as air temperature itself remined above 27 degrees f. the critical temperature for most Citrus. I am sure the Florida Departement Agriculture still has data on this effect that might benefit the researchers. After the freezes of the 1980's most of this land is now growing houses and orange juice "from Florida" arrives by ship at Port Manatee. I guess as long as it passes through Florida on it journey from Brazil to the public it is still "from Florida". Of course a little is still actually grown in FL but it is all "from FL"