This past winter we experienced blizzard white-out conditions with next to zero visibility. With the current weather pattern shift, we are continuing to see higher-level winds, and one of the best ways to combat this is by establishing shelterbelts.
A shelterbelt is a barrier of trees or shrubs. The term “field shelterbelt” is used to distinguish between rows of trees or shrubs on agricultural fields from those planted in other ways: around farmyards or livestock facilities (farmstead shelterbelts), on marginal lands to change land use or in block plantings to provide woodlots or wildlife habitat. Although modern agricultural farming practices such as direct-seeding have greatly reduced the amount of wind erosion in Alberta, there continues to be some effects of wind erosion on Alberta soils each year. Eroded soils are less productive, require higher inputs for crop production and are more prone to further erosion than uneroded soils. Erosion results in damage to downwind crops, structures and buildings, requiring costly cleanup and repair. Blowing topsoil has also been cited as a concern in numerous vehicle accidents, with several resulting in personal injury. Properly designed field shelterbelts, as part of a crop management system approach, prevent or greatly reduce the risk of wind erosion.
Properly placed field shelterbelts provide agronomic and other benefits. The main agronomic benefits include the following:
- reduced soil erosion by wind
- increased moisture for crop growth due to two factors: – snow trapping – reduced moisture loss through evaporation
- potential for increased crop yields
- reduced wind damage to crops
- wildlife habitat and shelter
- improved safety in winter travel due to reduced snow drifting
- lower costs of snow removal from roads
- beautification of the prairie landscape
- reduced environmental effects of agriculture
- provide a potential source of income for farmers (e.g. biomass, timber and non-timber products)
A field shelterbelt modifies the microclimate, mostly in its downwind vicinity. This modified microclimate includes reduced wind speed and, therefore, reduced soil erosion. Reduced wind erosion is the primary reason farmers have been planting field shelterbelts on the Canadian prairies for more than 90 years.
A significant reduction of wind speed occurs downwind for a distance extending to approximately 20 times the height of the shelterbelt and also 3 to 5 times its height on the upwind side. Therefore, a shelterbelt 5 m in height will provide a degree of protection for soils and crops for a total distance of up to 25 times its height, or 125 m
Since the zone of protection provided by a single shelterbelt is limited, a series of shelterbelts may be required to protect the whole field. Two to four rows are commonly planted per quarter section. Erosion-prone soils may require as many as eight shelterbelts per quarter section. The shelterbelts must be planted perpendicular to the direction of the prevailing wind to provide more complete protection.
Field shelterbelts reduce soil erosion by wind, conserve soil moisture and reduce wind damage to crops. They complement good crop residue management and other conservation practices to protect the soil. Field shelterbelts should not be considered as an alternative to good residue management but as a compliment. Field shelterbelts are a part of conservation management systems that will help safeguard the productive quality of our soils.
Field shelterbelts are a part of conservation management systems that will help safeguard the productive quality of our soils. Field shelterbelts offer many other benefits beyond conserving soil and soil moisture. For example, they provide shade and shelter for livestock and opportunities for supplemental farm income from the sale of berries, firewood, pulpwood or lumber. Shelterbelts also generate a variety of social benefits such as enhancing wildlife habitat, maintaining the regional groundwater balance, protecting watersheds, cycling oxygen (by taking in carbon dioxide, a greenhouse gas, and releasing oxygen) and providing a varied and attractive landscape.
Interested in establishing a shelterbelt?
Prairie Shelterbelt Program Ltd.
(403) 507 - 8340
HELP INTERNATIONAL SHELTERBELT CENTRE
(306) 861 - 0814 or (306) 842 -2433