Windbreak

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Shea butter trees planted near residential areas to serve as windbreaks Shea Butter Trees Planted Near Residential Areas to Serve as Windbreaks.jpg
Shea butter trees planted near residential areas to serve as windbreaks

A windbreak (shelterbelt) is a planting usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted in hedgerows around the edges of fields on farms. If designed properly, windbreaks around a home can reduce the cost of heating and cooling and save energy. Windbreaks are also planted to help keep snow from drifting onto roadways or yards. [1] Farmers sometimes use windbreaks to keep snow drifts on farm land that will provide water when the snow melts in the spring. Other benefits include contributing to a microclimate around crops (with slightly less drying and chilling at night), providing habitat for wildlife, [2] and, in some regions, providing wood if the trees are harvested.

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Windbreaks and intercropping can be combined in a farming practice referred to as alley cropping, or being deployed along riparian buffer stripes. [3] Fields are planted in rows of different crops surrounded by rows of trees. These trees provide fruit, wood, or protect the crops from the wind. Alley cropping has been particularly successful in India, Africa, and Brazil, where coffee growers have combined farming and forestry. [4]

A further use for a shelterbelt is to screen a farm from a main road or motorway. [5] This improves the farm landscape by reducing the visual incursion of the motorway, mitigating noise from the traffic and providing a safe barrier between farm animals and the road.

Fences called "windbreaks" are also used. Normally made from cotton, nylon, canvas, and recycled sails, windbreaks tend to have three or more panels held in place with poles that slide into pockets sewn into the panel. The poles are then hammered into the ground and a windbreak is formed. Windbreaks or "wind fences" are used to reduce wind speeds over erodible areas such as open fields, industrial stockpiles, and dusty industrial operations. As erosion is proportional to wind speed cubed, a reduction of wind speed of 1/2 (for example) will reduce erosion by 87.5%.[ citation needed ]

Sheltered, windless areas created by windbreaks are called wind shadows. [6]

Windbreaks can mitigate the effects of pesticide drift. [7]

Windbreak aerodynamics

An East German windbreak promotion poster, 1952 Bundesarchiv Bild 183-15117-0005, Infografik, Windschutz, Ertragssteigerung.jpg
An East German windbreak promotion poster, 1952

When wind encounters a porous obstacle, such as a windbreak or shelterbelt, air pressure increases on the windward side and decreases on the leeward side. As a result, the airstream approaching the barrier is interrupted, and a portion of it moves over the barrier, resulting in a jet of higher wind speed. The remainder of the airstream then moves through the barrier to its edge downstream, pushed along by the decrease in pressure across the shelterbelt's width; as it emerges again, that airstream is interrupted further as its air pressure adjusts to the surrounding area. This results in slower wind speed further downwind, reaching a minimum at a distance of about 3 to 5 times the windbreak's height. Beyond that point wind speed recovers, aided by the overlying, faster-moving stream. From the perspective of the Reynolds-averaged Navier–Stokes equations, these effects can be understood as resulting from the loss of momentum caused by the drag of leaves and branches and would be represented by the body force fi (a distributed momentum sink). [8]

Windbreaks reduce the wind's average air speed and make it less variable, resulting in the wind mixing less effectively than it does upwind. Additionally, all these changes to the wind's behavior result in changes to the region's environment. For instance, the surface energy budget of the ground may be impacted, as the slowed wind dissipates heat from the sun less effectively; this trend may reverse further downwind, and about 8 times the windbreak's height downstream, the windbreak may result in cooler surface temperatures. [9]

Windbreak organizations

See also

Related Research Articles

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Soil erosion is the denudation or wearing away of the upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, and animals. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind (aeolian) erosion, zoogenic erosion and anthropogenic erosion such as tillage erosion. Soil erosion may be a slow process that continues relatively unnoticed, or it may occur at an alarming rate causing a serious loss of topsoil. The loss of soil from farmland may be reflected in reduced crop production potential, lower surface water quality and damaged drainage networks. Soil erosion could also cause sinkholes.

<span class="mw-page-title-main">Prairie</span> Ecosystems considered part of the temperate grasslands, savannas, and shrublands biome

Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type. Temperate grassland regions include the Pampas of Argentina, Brazil and Uruguay, and the steppe of Ukraine, Russia, and Kazakhstan. Lands typically referred to as "prairie" tend to be in North America. The term encompasses the lower and mid-latitude of the area referred to as the Interior Plains of Canada, the United States, and Mexico. It includes all of the Great Plains as well as the wetter, hillier land to the east. From west to east, generally the drier expanse of shortgrass prairie gives way to mixed grass prairie and ultimately the richer soils of the tallgrass prairie.

<span class="mw-page-title-main">Hedge</span> Planted row of shrubs

A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoining fields or one field from another, and are of sufficient age to incorporate larger trees, are known as hedgerows. Often they serve as windbreaks to improve conditions for the adjacent crops, as in bocage country. When clipped and maintained, hedges are also a simple form of topiary.

<span class="mw-page-title-main">Agroforestry</span> Land use management system

Agroforestry is a land use management system that integrates trees with crops or pasture. It combines agricultural and forestry technologies. As a polyculture system, an agroforestry system can produce timber and wood products, fruits, nuts, other edible plant products, edible mushrooms, medicinal plants, ornamental plants, animals and animal products, and other products from both domesticated and wild species.

<span class="mw-page-title-main">Soil conservation</span> Preservation of soil nutrients

Soil conservation is the prevention of loss of the topmost layer of the soil from erosion or prevention of reduced fertility caused by over usage, acidification, salinization or other chemical soil contamination.

<span class="mw-page-title-main">Afforestation</span> Establishment of trees where there were none previously

Afforestation is the establishment of a forest or stand of trees in an area where there was no recent tree cover. There are three types of afforestation: Natural regeneration, agroforestry and tree plantations. Afforestation has many benefits. In the context of climate change, afforestation can be helpful for climate change mitigation through the route of carbon sequestration. Afforestation can also improve the local climate through increased rainfall and by being a barrier against high winds. The additional trees can also prevent or reduce topsoil erosion, floods and landslides. Finally, additional trees can be a habitat for wildlife, and provide employment and wood products.

<span class="mw-page-title-main">Silvopasture</span> Agricultural practice of grazing animals in woodland

Silvopasture is the practice of integrating trees, forage, and the grazing of domesticated animals in a mutually beneficial way. It utilizes the principles of managed grazing, and it is one of several distinct forms of agroforestry.

<span class="mw-page-title-main">Multipurpose tree</span> Trees grown and managed for more than one output

Multipurpose trees or multifunctional trees are trees that are deliberately grown and managed for more than one output. They may supply food in the form of fruit, nuts, or leaves that can be used as a vegetable; while at the same time supplying firewood, adding nitrogen to the soil, or supplying some other combination of multiple outputs. "Multipurpose tree" is a term common to agroforestry, particularly when speaking of tropical agroforestry where the tree owner is a subsistence farmer.

The Prairie Farm Rehabilitation Administration (PFRA) was a branch under Agriculture and Agri-Food Canada (AAFC), a department of the Federal Government of Canada.

<span class="mw-page-title-main">Erosion control</span> Practice of preventing soil erosion in agriculture and land development

Erosion control is the practice of preventing or controlling wind or water erosion in agriculture, land development, coastal areas, river banks and construction. Effective erosion controls handle surface runoff and are important techniques in preventing water pollution, soil loss, wildlife habitat loss and human property loss.

<span class="mw-page-title-main">Conservation Reserve Program</span> U.S. federal aid program

The Conservation Reserve Program (CRP) is a cost-share and rental payment program of the United States Department of Agriculture (USDA). Under the program, the government pays farmers to take certain agriculturally used croplands out of production and convert them to vegetative cover, such as cultivated or native bunchgrasses and grasslands, wildlife and pollinators food and shelter plantings, windbreak and shade trees, filter and buffer strips, grassed waterways, and riparian buffers. The purpose of the program is to reduce land erosion, improve water quality and effect wildlife benefits.

<span class="mw-page-title-main">Social forestry in India</span> Forestry intended to help environmental, social, and rural development

Social forestry is the management and protection of forests and afforestation of barren and deforested lands with the purpose of helping environmental, social and rural development. The term social forestry was first used in 1976 by The National Commission on Agriculture, when the government of India aimed to reduce pressure on forests by planting trees on all unused and fallow lands. It was intended as a democratic approach to forest conservation and usage, maximizing land utilization for multiple purposes.

<i>Caragana arborescens</i> Species of flowering plant

Caragana arborescens, the Siberian peashrub, Siberian pea-tree, or caragana, is a species of legume native to Siberia and parts of China and neighboring Mongolia and Kazakhstan. It was taken to the United States by Eurasian immigrants, who used it as a food source while travelling west. In some areas of the United States it is considered an invasive species. Introduced on the Canadian prairies in the 1880's, the hardy caragana provided shelter-belts, wildlife habitat, nitrogen fixation, and windbreaks to prevent soil erosion and snow drifting.

<span class="mw-page-title-main">Buffer strip</span>

A buffer strip is an area of land maintained in permanent vegetation that helps to control air quality, soil quality, and water quality, along with other environmental problems, dealing primarily on land that is used in agriculture. Buffer strips trap sediment, and enhance filtration of nutrients and pesticides by slowing down surface runoff that could enter the local surface waters. The root systems of the planted vegetation in these buffers hold soil particles together which alleviate the soil of wind erosion and stabilize stream banks providing protection against substantial erosion and landslides. Farmers can also use buffer strips to square up existing crop fields to provide safety for equipment while also farming more efficiently.

<span class="mw-page-title-main">Riparian buffer</span> Vegetated area near a stream, usually forested

A riparian buffer or stream buffer is a vegetated area near a stream, usually forested, which helps shade and partially protect the stream from the impact of adjacent land uses. It plays a key role in increasing water quality in associated streams, rivers, and lakes, thus providing environmental benefits. With the decline of many aquatic ecosystems due to agriculture, riparian buffers have become a very common conservation practice aimed at increasing water quality and reducing pollution.

<span class="mw-page-title-main">Paha (landform)</span> Type of loess hill

Paha are elongated landforms composed either of only loess or till capped by loess. In Iowa, paha are prominent hills that are oriented from northwest to southeast, formed during the period of mass erosion that developed the Iowan surface, and they are considered erosional remnants since they often preserve buried soils. Paha generally rise above the surrounding landscape more than 6.1 metres (20 ft). The word paha means hill in Dakota Sioux. Well known pahas include the hill on which the town of Mount Vernon, Iowa developed, Casey's Paha in Tama County, Iowa, and the Kirkwood Paha, home of Kirkwood Community College's campus. These features are found in other regions of the United States and in Europe, where they are known as greda.

<span class="mw-page-title-main">Sand fence</span> Erosion control structure

A sand fence or sandbreak, similar to a snow fence, is a barrier used to force windblown, drifting sand to accumulate in a desired place. Sand fences are employed to control erosion, help sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas. Sand fences are also commonly employed following storm events in order to aid in the dune recovery process, particularly in developed areas where dunes are critical for protection of property.

<span class="mw-page-title-main">Great Plains Shelterbelt</span> Areas between Canada and West Texas afforested as part of the New Deal

The Great Plains Shelterbelt was a project to create windbreaks in the Great Plains states of the United States, that began in 1934. President Franklin D. Roosevelt initiated the project in response to the severe dust storms of the Dust Bowl, which resulted in significant soil erosion and drought. The United States Forest Service believed that planting trees on the perimeters of farms would reduce wind velocity and lessen evaporation of moisture from the soil. By 1942, 220 million trees had been planted, covering 18,600 square miles (48,000 km2) in a 100-mile-wide zone from Canada to the Brazos River. Even as of 2007, "the federal response to the Dust Bowl, including the Prairie States Forestry Project which planted the Great Plains Shelterbelt and creation of the Soil Erosion Service, represents the largest and most-focused effort of the [U.S.] government to address an environmental problem".

The environmental impact of agriculture is the effect that different farming practices have on the ecosystems around them, and how those effects can be traced back to those practices. The environmental impact of agriculture varies widely based on practices employed by farmers and by the scale of practice. Farming communities that try to reduce environmental impacts through modifying their practices will adopt sustainable agriculture practices. The negative impact of agriculture is an old issue that remains a concern even as experts design innovative means to reduce destruction and enhance eco-efficiency. Animal agriculture practices tend to be more environmentally destructive than agricultural practices focused on fruits, vegetables and other biomass. The emissions of ammonia from cattle waste continue to raise concerns over environmental pollution.

<span class="mw-page-title-main">Desert greening</span> Process of man-made reclamation of deserts

Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life. The term "desert greening" is intended to apply to both cold and hot arid and semi-arid deserts. It does not apply to ice capped or permafrost regions. It pertains to roughly 32 million square kilometres of land. Deserts span all seven continents of the Earth and make up nearly a fifth of the Earth's landmass, areas that recently have been increasing in size.

References

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  2. "Role of trees in agriculture" . Retrieved 13 February 2018.
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  5. Hetlzer, Robert (1972). Soil Survey of Walsh County, North Dakota. United States NRCS Soil Conservation Service. p. 75.
  6. Matthews, John A. (2014), "WIND SHADOW", Encyclopedia of Environmental Change, SAGE Publications, Ltd., p. 1175, doi:10.4135/9781446247501, ISBN   9781446247112 , retrieved 30 March 2020
  7. Ucar, Tamer; Hall, Franklin R. (2001). "Windbreaks as a pesticide drift mitigation strategy: A review". Pest Management Science. 57 (8): 663–675. doi:10.1002/ps.341.
  8. Wilson, John D. (1985). "Numerical studies of flow through a windbreak". Journal of Wind Engineering and Industrial Aerodynamics. 21 (2): 119–154. doi:10.1016/0167-6105(85)90001-7.
  9. Argete, J.C; Wilson, J.D (1989). "The microclimate in the centre of small square sheltered plots". Agricultural and Forest Meteorology. 48 (1–2): 185–199. Bibcode:1989AgFM...48..185A. doi:10.1016/0168-1923(89)90016-6.