By Natalie Euler
Natural Resource Specialist, Northwest Area Conservation Districts
Windbreaks can provide protection from high winds and blowing snow. In open areas, winds lift, carry and deposit snowflakes. Windbreaks modify wind flow and distribute blowing snow. There are several different types of windbreaks: field windbreaks, living snow fences, farmsteads and feedlot windbreaks and livestock protection shelterbelts, all require proper planning, implementation and maintenance.
Field windbreaks can be used to spread out snow across fields providing soil moisture for crops and forage production during the next growing season. Studies have shown that on average, wheat yields are increased by 15 to 20 percent. Field windbreaks need to be designed to have a 40% density in order to provide uniform snow distribution across a field. This can be accomplished by planting a single row of tall deciduous trees at 15 to 20 feet spacing perpendicular to the prevailing winds. Single rows should be evenly spaced across the field at a distance 10 to 15 times the expected mature height of the trees.
Living Snow Fences are an effective method of controlling blowing snow. Living snow fences can be planted along highways, roads and driveways to provide public benefits, livestock protection, crop protection, wildlife habitat, and aesthetic value. Living snow fences achieve optimum storage capacity when winter density is about 50 to 60 percent. Density will vary with the number and spacing of tree rows, tree species. The height of the trees is important since snow storage capacity increases more than four times when height doubles.
A living snow fence needs to be located perpendicular to the prevailing winter winds and the area to be protected located downwind. The worst winter winds come from the northwest, north, or northeast. Living snow fences should be located on the north side of east-west roads and the west side of north-south roads. They should be located a minimum of 175 feet from the centerline of the roads and no closer than 200 feet from corners or intersections for traffic visibility.
Farmstead or feedlot windbreaks reduce the force of winter winds and create a sheltered zone or microclimate on the downwind sides of windbreaks. These windbreaks provide protection from blowing and drifting snow. Without windbreak protection, farmhouses and other structures are at the mercy of severe swirling wind currents and snow drifting, requiring additional hours of labor for snow removal. Feedlot and livestock windbreaks can be used to maintain areas free from deep snow where hay and feed are stored. Livestock are able to get out of strong winds and driving snow, reducing animal stress, decreasing feed requirements, resulting in better animal health, lower death loss, and lower feed costs.
Farmstead and feedlot windbreaks should be located so that the windward row is a least 150 feet from buildings, driveways and feed bunks to provide room for snow drifting downwind. There should be 75 to 100 feet from the downwind side of the windbreak and the area to be protected. There should be at least 50 feet between the windbreak and roads or other features that may be within the zone of the windward snowdrift. Also, the windbreak should be extended 100 feet beyond the area to be protected to prevent the drifts from forming at the ends.
My source for this news release was the South Dakota Department of Agriculture Division of Resource Conservation and Forestry. If you would like more information about “Windbreaks and Snow Management,” contact Natalie Euler at the Conservation Office at 605-244-5222, Extension 4 or by e-mail at [email protected]