Windbreaks, hedgerows and shelterbelts

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1 Windbreaks, hedgerows and shelterbelts Why should you be concerned? Windbreaks, hedgerows or shelterbelts are effective in improving the quality of the environment on and off the farm by providing a wind barrier to protect crops, buildings and livestock and provide habitat for wildlife. For exemple a 10 metre windbreak with a 60% density can reduce wind velocity by 50% over a distance as great as 10 times its height that is over 100 metres. Removing fencerows to increase field size has increased the risk of wind erosion. Windbreaks can be effective as a single wind erosion control measure, however, their cost effectiveness can be greatly improved when combined with other measures such as residue management, crop rotation, strip cropping and conservation tillage. Most crops produce higher yields and better quality when protected from the negative effects of winds. Significant yield increase and crop quality improvement have been attributed to the shelter effects of windbreaks which provide lower temperatures during the day and warmer temperatures during the night. Other benefits include higher relative humidity, reduced evapotranspiration, improved soil moisture, higher pollination and less physical wind damage to crops. The degree of response varies with the crop, weather condition, soil type and windbreak design. Literature quotes a 6 to 19% increase in total potato yield,due to greater tuber size, when fields are protected with windbreaks. The benefits for vegetable and fruit production are considerably greater due to a reduction in mechanical damage and improved pollination. Crops that benefit from additional heat units have shown yield increases ranging from %. In Ontario, soybean yield increased by 30% and corn yield improved by 6 to 8%. Other field crops such as alfalfa, hay, spring and winter cereals also benefited. Spring wheat and oats responded to a lesser extent. Properly designed windbreaks can be an effective tool in snow and water management. A dense windbreak can be used to control snow drifts while a lower density windbreak can be used to distribute snow uniformly over a distance as great as 25 times the height of the trees. Perennial crops such as strawberries, blueberries, alfalfa and winter cereals which depend highly on snow cover will benefit greatly from windbreaks. Research in Quebec has demonstrated a 2.4 times higher blueberry yield with the use of windbreaks. By protecting livestock from cold and wind in the winter and heat in the summer, windbreaks improve the productivity of livestock operations, enhancing feed utilization and weight gain. The amount of feed required to maintain the body temperature is reduced in a wind protected area while animals protected from heat in the summer will graze more. Windbreaks can protect the working environment in and around the livestock area and screen noise and odour associated with livestock operations.

2 The utilization of windbreaks for the protection of the farmstead and for energy saving is well known. The protected environment assures a more comfortable living area while providing considerable energy savings both in the winter and summer. Energy costs can be cut by as much as 10 to 40% depending on the weather, wind conditions in the area, windbreak and building design. Heat loss from greenhouses can be reduced by 10 to 15%. Established windbreaks also improve the off-farm environment by acting as dust and sound barriers, as well as reducing pesticide drift. A well designed windbreak can reduce dust and noise by 30%. Although it is not an acceptable management practice to spray pesticides when wind speed is greater than 10 km/hr, the use of well designed field windbreaks may allow spraying when wind blows at almost twice this speed while maintaining pesticide drift at a minimal level. In many intensively farmed areas, windbreaks or shelterbelts may be the only meaningful and critical habitat for wildlife providing protection from wind and adverse weather. Windbreaks also provide refuge cover, food, reproductive and nesting sites and travel corridors. The diversity of wildlife present in the windbreak is dependent on the width and diversity of the shelter and its integration or connection with other wildlife habitats ie: forest, woodlot or old fields. Certain wildlife prefer wide shelterbelts over narrow windbreaks. The height is not as important as the presence of a ground cover. It has been demonstrated that leaving an unsprayed edge along the windbreaks will increase abundance of wildlife in the habitat. This may be due to a direct or indirect impact of pesticides. The wood harvested from windbreaks can be an important source of income for producers. Windbreaks are also beneficial to the landscape contributing to the beauty and diversity of the countryside thus increasing the value of the farmstead and the farmland. The incorporation of agroforestry species such as fruit or nut bearing shrubs or trees in the windbreaks may also provide added revenue to the family. What can you do? To be effective, field, livestock and farmstead windbreaks need to be properly planned and managed. The planning process involves a review of your current and future requirements taking into consideration your long term soil, water and energy conservation objectives. The following are tips that may assist you in your planning process:! By using the maps of your farm, locate existing windbreaks, natural fencerows, buildings, farm access roads. Identify the prevailing summer and winter wind directions and locate problem areas.! Evaluate what can be done to improve existing windbreaks and natural fencerows. They may require thinning, pruning or interplanting of new trees.! If existing windbreaks are competing with adjacent crops for moisture, root pruning by deep ripping between the windbreak and the crop may be necessary or you may leave a strip of grass between the crop and the windbreak. The latter will also be beneficial to wildlife by providing added nesting area and food.! Identify the species of trees and shrubs which are best adapted for your area in terms of soil and climate conditions. Low maintenance, fast growth and longevity are all desirable features. In all cases, the species should be resistant to stem and branch breaking and have a low to moderate crown and root spread. If planting along salt water shorelines and highways, salt tolerant species should be selected. For field windbreaks, select trees and shrubs which are resistant to pests and herbicides. Trees and shrubs in livestock windbreaks should be tolerant of high nitrogen and phosphorus concentrations from manure and feedlot. Farmstead windbreaks will include aesthetically pleasing trees and shrubs.! Although single row windbreaks can be effective, multi -row windbreaks with multiple species provide added benefits such as reducing the risk of losing the windbreak due to a pest infestation. Multi-row windbreaks also provide a better habitat for wildlife and greater potential for agroforestry income to the farm. A considerable amount of snow can also be trapped within the windbreak, causing less disruptions to early field operations. WB 2

3 Section WB Resource List For more information... Windbreaks, hedgerows and shelterbelt resources Prince Edward Island. Farmstead windbreaks. Agri-Fact Factsheet, Agdex 751, pp Schneider, G. Native Shrubs of Prince Edward Island. PEI Department of Fisheries and Environment. pp 44, Ontario Ministry of Natural Resources. The benefits of Windbreaks, extension notes. Agdex 573, pp 4, Ontario Ministry of Natural Resources. Designing and Caring for Windbreaks. pp 6, Ontario Ministry of Agriculture and Food. Best Management Practices, Farm Forestry and Habitat Mangement. pp 41, New Brunswick Department of Agriculture. Windbreaks. Agdex 202/10, pp 3, Prairie Farm Rehabilitation Administration Planning Farm Shelterbelts. pp 5, Field Shelterbelts for the Prairies. pp 9, University of Nebraska Windbreaks for rural living. pp 6, publ: EC X Windbreaks for livestock operations. pp 6, publ: EC X The Tree Project. Windbreaks, trees and shrubs for crop protection. pp13. Alberta Agriculture. Field Shelterbelts for Soil Conservation. Agdex 277/20-3, pp 14, Definitions: Windbreak density: Amount of space in the windbreak through which air can travel; or amount of light that can be seen through a windbreak; or percentage of the background scene that is blocked from view when standing away from the windbreak and looking perpendicularly through it. Height (H): Refers to the expected height at maturity of the tallest tree or shrub row in the windbreak (ex: when referring to area protected, 20 H = 20 times the expected height) WB 3

4 Field windbreaks: How do you rate? Properly designed and managed field windbreaks are effective in controlling wind erosion, deposit snow uniformly, improve water use efficiency, reduce wind damage to crops. As a result, crop yield and quality are improved. The effectiveness of field windbreaks is dependant on their height, density, length, spacing and orientation. The ideal field windbreak system consist of a series of multi-row windbreaks oriented at a 90 degree angle to prevailing winds. The distance between the windbreaks does not exceed 15 H (15 times the expected tree height) and the density is maintained at 50%. Although these conditions can not be met for most fields, they should be part of the objectives when designing windbreaks for fields needing the most protection. Trees and shrubs selected for field windbreaks should be resistant to diseases, insects, rodents and to potential pesticide drifts. If windbreaks are located near salt water shorelines or roads, salt resistant species should be selected. Field Windbreaks 1 Height and spacing The windbreaks are spaced atthe windbreaks are spaced atwindbreaks are spaced at a 10 to 15 times their height (height at maturity). 15 to 20 times their height. distance greater than 20H. Other soil conservation measures are used in the system. Other soil conservation measures are used in the system. No windbreaks. Intensively cultivated cropping system 2 Density and uniformity The trees and shrubs are providing a uniform wind barriers with 40 to 60% density during the cropping season. Shrubs are included in the windbreak to provide a uniform density at the bottom of the windbreak. The windbreak has an overall density of 40 to 60% but not uniform across its length and height. Snow distribution is not uniform and accumulates in areas close to the windbreak. Windbreak is too thick, actingno windbreak. as a solid wall. Snow accumulates close to or windbreak. Windbreak density across its height or width varies too much. WB 4 FIELD WINDBREAKS

5 Field Windbreaks cont d 3 Orientation Windbreak is oriented at a Windbreak is oriented between Windbreak is oriented betweenno windbreak right angle ( 90 0 ) to prevailing45 0 and 90 0 angle to 45 0 and 90 0 angle to winds. prevailing winds. Density andprevailing winds. Density andor windbreak spacing is adjustedspacing not adjusted. or accordingly. Windbreaks on all sides of the or field. On side where crop shading may be a problem, Windbreaks are protecting the short growing species are North and West side of the selected. field. Windbreak oriented at angle too sharp to provide any wind protection. 4 Length of windbreak Windbreak is long, extendingwindbreak does not extend at least 15 metres beyond each beyond the area needing side of area needing protection protection. or is surrounding the area. The windbreak is continuous without any gaps on its entire length except where frost pockets are a problem. Windbreak is continuous but does not cover the full area needing protection. No windbreak Or Windbreaks are broken up with too many openings. 5 Wildlife protection and diversity Windbreak consists of at least Windbreak consists of at leastwindbreak consists of one rowno windbreak three rows of trees and shrubs two rows of trees and shrubs of trees and shrubs of mixed species. A ground cover is left between windbreak and field and at the bottom of windbreak. WB 5 FIELD WINDBREAKS

6 Livestock Windbreaks: How do you rate? A T L A N T I C E N V I R O N M E N T A L F A R M P L A N W O R K B O O K Properly designed livestock windbreaks are designed to protect the livestock from heat in the summer and from cold winds in the winter. This protection reduces the impact of climatic extremes on livestock thus improving their health and productivity and reducing their mortality rate. Less feed energy is needed to maintain livestock body heat during the winter while less heat or more shading in the summer increases the animal food consumption. Windbreaks for livestock protection are designed to reduce the speed of wind without creating drafts or turbulence. A well designed windbreak will reduce snow drifting in the feedlot and improve the working environment. Trees selected for livestock windbreaks should have some tolerance to high nitrogen and phosphorus concentrations. Livestock Windbreaks 1 Location, orientation and other management Windbreaks are located on theonly one windbreak orientedonly one windbreak oriented No windbreaks North and West side of the feedlot or planted at a 90 0 between 45 0 and 90 0 angle tobetween 45 0 and 90 0 angle to prevailing winds. Density andprevailing winds. Density andor angle to the prevailing winds. windbreak spacing are adjusted windbreak spacing are not accordingly. adjusted accordingly. Located 30 to 60 metres (2-5 H) from feedlot and area Runoff is not controlled and on protected area. needing protection. livestock are not fenced out of Animal waste runoff are diverted away from the windbreak or a buffer strip is placed between windbreak and feedlot. Runoff is controlled and livestock are fenced out of windbreak. windbreak. Windbreak located too close to feedlot creating snow drifting Runoff is not controlled and livestock are not fenced out. Water from melting snow is diverted away from feedlot. Livestock are fenced away from windbreak. WB 6 LIVESTOCK WINDBREAKS

7 Livestock Windbreaks 2 Density and uniformity The trees and shrubs are providing a uniform wind The windbreak has an overall density of 60 to 80% but not barrier with 60 to 80% density uniform across its length and year round. height. Shrubs are included in the Snow distribution is not Snow drifting in feedlot area windbreak to provide a uniform uniform and accumulates in but there are no sign of density at the bottom of the areas along the windbreak butturbulence. windbreak. The windbreak is continuous without any gaps and extends at least 15 metres beyond each side of area needing protection or its end extends into an L shape. there are no signs of turbulence or drifting in the feedlot area. The windbreak has an overall No windbreaks density of less than 60% but is uniform across its length and or height. To many gaps in windbreak creating turbulence and snow drifting in feedlot area. 3 Wildlife protection, diversity Windbreak consists of at leastwindbreak consists of at least Windbreak consists of one rowno windbreak. three rows of trees and shrubsone row of trees and one row of conifers. of shrubs. WB 7 LIVESTOCK WINDBREAKS

8 Homestead Windbreaks: How do you rate? Farmstead or homestead windbreaks are designed to reduce energy loss from buildings and trap snow away from the homestead, working area and roads. Buildings protected from wind will be warmer in the winter and cooler in the summer. The windbreaks will provide an improved working and recreation environment while giving a more scenic view of the farmstead and potentially increase its value. It will also reduce dust and noise coming from within or outside the farmstead. The trees selected should have a low to moderate root and crown spread if near utility lines or a sewage system. Species selected are normally aesthetically pleasing to increase farmstead value. Homestead windbreaks 1 Location, orientation and other management Windbreaks are located on theonly one windbreak orientedonly one windbreak oriented No windbreaks North and West side of the homestead or planted between 45 0 and 90 0 angle tobetween 45 0 and 90 0 angle to prevailing winds. Density andprevailing winds. Density andor perpendicular to the prevailingwindbreak spacing are adjusted windbreak spacing are not winds. accordingly. adjusted accordingly. Located 30 to 60 metres (2-5 H) from buildings and area needing protection. Water from melting snow is Water is not diverted away diverted away from farmsteadfrom farmstead. and roads. Windbreak located to close to buildings, driveway or farm yard creating snow drifting on protected area. Water from melting snow is diverted away from yard, buildings and roads. WB 8 HOMESTEAD WINDBREAKS

9 2 Density and uniformity The trees and shrubs are providing a uniform wind The windbreak has an overall density of 60 to 80% but not barrier with 60 to 80% density uniform across its length and year round. height. The windbreak has an overall No windbreaks density of less than 60% but is uniform across its length and or height. Shrubs are included in the Snow distribution is not Snow is drifting and windbreak to provide a uniform uniform and accumulates in accumulating near buildings density at the bottom of the windbreak. areas along the windbreak butand area needing wind there are no signs of turbulence protection. or drifting near buildings or The windbreak is continuous farm yard. without any gaps and extends at least 15 metres beyond each side of area needing protection or its end extends into an L shape. To many gaps in windbreak creating turbulence and snow drifting and accumulating in area needing protection. 3 Wildlife protection, diversity Windbreak consist of at least Windbreak consist of at leastwindbreak consist of one rowno windbreak. three rows of trees and shrubsone row of trees and one row of conifers. of shrubs. Fruit bearing shrubs are included in the outer row for added wildlife benefit, snow trapping and to beautify the landscape. WB 9 HOMESTEAD WINDBREAKS

10 Living Snowfences: How do you rate? The purpose of a snowfence is to concentrate snow deposition away from farm roads, buildings and other areas. Living snowfences will provide greater storage and longer snow control than a slatted snowfence. An efficient living snowfence will decrease snow removal cost thought the winter, enhance the esthetic appeal of the landscape and provide cover and food to wildlife. Trees and shrubs should be resistant to stem and branch breakage, and resistant to pests and pesticides. Evergreen or densely branched trees and shrubs with low to moderate root and crown spread are preferred. Living snowfence 1 Location The snowfence is located 30 to 60 metres (2-5H) from area needing protection Snowfence is located further than 60 metres from area needing protection. The density of windbreak is reduced accordingly. No snowfence or Snowfence located to close or to far from area needing protection. Snow is accumulating in access roads and building. 2 Density and uniformity of snowfence The snowfence is uniform The snowfence is uniform across its length and height across its height and length with a density of 80 to 100% with a density of 60 to 80% No snowfence or Snowfence is too thin. Snow accumulates on area needing protection. WB 10 LIVING SNOWFENCES

11 3 Orientation Windbreak is oriented at a Snowfence is oriented between right angle ( 90 0 ) to prevailing45 0 and 90 0 angle to winds. prevailing winds. No snowfence Or Snowfence oriented at angle less than 45 0 angle to prevailing winds. 4 Length of snowfence Snowfence is long extending Snowfence at does not extend least 15 metres beyond each beyond the area needing side of area needing protection protection. or is surrounding the area. The snowfence is continuous without any gaps. Snowfence is continuous but does not cover the full area needing protection. No snowfence Or Snowfence is broken up with too many gaps. 5 Wildlife protection and diversity Snowfence consists of at least Snowfence consists of at leastsnowfence consists of one rowsnowfence consists of one row three rows of trees and shrubs two rows of trees and shrubs of trees and shrubs of mixed of tall growing trees giving species. minimal food and travel corridor to wildlife. A ground cover is left at the bottom of windbreak. WB 11 LIVING SNOWFENCES