Many of the aspects of microclimates that affect plant ecology also apply to agriculture. Good farmers plan their planting to avoid unfavorable microclimates— avoiding frost pockets for sensitive crops, and allowing for the effect of aspect on temperature or water balance. They can also try to make new microclimates which will favor the plants they are growing. Shelter belts of planted trees or bushes create a drag that slows down the drying or cooling winds that blow across farmland. The effect of a shelter belt of trees on wind speed can extend across the field as far as 20 to 30 times the height of the trees.
Greenhouses and other covers in agriculture are all about forming a microclimate. It used to be thought that greenhouses worked mainly by letting visible light in and preventing infra-red light from leaving, because glass strongly absorbs infrared light. It is now known that in fact greenhouses mostly just heat up because (having a roof on the top) they prevent heated air from rising away into the atmosphere by convection, as it would outside. However the old idea has left a legacy in science in the term "greenhouse effect'' which refers to the way certain gases in the atmosphere trap heat by letting visible light in but blocking infra-red light on its way out.
The shade and coolness of the forest understory is artificially created in agro-forestry, a mainly tropical practice of growing crop plants under and between rows of trees. Many plants, such as cocoa bushes, do especially well when shaded like this, because they are descended from wild plants which naturally grow in the forest understory.
Citrus growers in California or Florida sometimes resort to putting radiant heaters in the open air of the orchards if a frost is threatening; it is a very inefficient use of fossil fuel energy, but often works just well enough to keep frost off the plants. In another trick to save crops, rice farmers in northern Japan often raise the water level in their rice fields to flood the plants with a layer of insulating water to protect them against a sudden cold spell, during the most sensitive period when the rice is flowering and the grains are beginning to form.
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