Which of the following is NOT mentioned as the benefit of growing windbreaks?

Soil conservation methods help fanners protect their land from the damage caused by fanning and the forces of nature. One method of soil conservation is the use of windbreaks. Windbreaks are barriers formed by trees and other plants. Farmers plant these barriers around their fields.(27)They stop the wind from blowing soil away. They also keep the wind from damaging or destroying crops.
    Windbreaks can be highly valuable for protecting grain crops. For example, studies have been done on windbreaks in parts of West Africa. These studies found that grain harvests were as much as twenty percent higher in fields protected by windbreaks compared to fields without them.
    But here is something interesting about windbreaks.(28)They seem to work best when they allow some wind to pass through the barrier of trees or plants around a field. If not, then the movement of air close to the ground will lift the soil. Then the soil will be blown away.