Windbreaks
The agroforestry and sustainable land use practice of using windbreaks to manage, improve, and enhance a landowner's farm and income is beneficial to the environment as well. It is again important to understand how the components work together to create an effective system of agroforestry. A windbreak can be established by planting trees, shrubs, and/or grasses bordering crops or fields of livestock. Designing a windbreak requires the consideration of many factors including the local climate, crops grown, and land topography.
Benefits to a properly established windbreak include improved livestock production and husbandry, better crop production, and soil conservation. The windbreaks can actually be a part of the active farm income when plantings of trees and plants not only provide wind protection, but also can be harvested for crops themselves. For instance, nut trees, fruit trees, and evergreen trees have the added benefit of producing income-generating goods.
Any barrier that reduces winds by creating a wind shadow can be considered a windbreak. Windbreaks are both natural and fabricated. The function of a windbreak is to reduce the speed of the wind and its potentially damaging effects. In order to be effective, a windbreak needs to be at least 2 ½ feet high. Natural windbreaks can include shrubs, trees, and tall plants such as sunflowers.
Natural windbreaks are also called timberbelts or shelterbelts and use a management style that is both intensive and knowledgeable. Typically, a natural windbreak consists of one or more rows of trees or shrubs that are planted in close proximity at a right angle to the wind. A properly placed and constructed windbreak will modify the air movement and speed of the wind. While a windbreak and shelterbelt are interchangeable terms, timberbelt signifies that there is additional income from the harvesting of trees used for windbreaks.
Reduction of soil erosion is an excellent additional benefit of windbreaks and the soil quality is also enhanced by the root system of the trees and shrubs. Tree roots are deeper reaching than other plants and can pull up lower layers of nutrients to the top layers of soil. Protection from light, noise, and snow are a few more advantages to planting windbreaks. By preventing heat loss from buildings by reducing the infiltration of cold air, energy costs are reduced. The aesthetic element of beauty is enhanced with the increased amount of wildlife that will use the windbreak for their habitat.
There are a few disadvantages to the use of windbreaks, such as the need for specialized equipment to manage effectively the tree and shrub maintenance. Using the land for tree growth will also limit the amount of ground that can be used for crop growth or livestock production and will not likely provide income in the short-term span. Fortunately, the downside of windbreaks is a short list and can more often than not be overcome with efficient use of space and adequate planning. For instance, properly planted windbreaks can increase winter wheat yields by more than 20%, which means that the loss of income from the windbreak planting is more than likely made up with the increase in crop yield.