An agroforestry practice
This presentation was developed by the USDA National Agroforestry Center
Presentation Objectives
Define windbreaks
 Describe the benefits and types
 Recognize basic design considerations
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Windbreaks
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What is Agroforestry?
…the intentional combining of
agriculture and working trees to
create sustainable farming systems.
Riparian buffer
Forest farming
Alley cropping
Silvopasture
Windbreaks
Windbreaks
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What is a windbreak?

Plantings of single
or multiple rows of
vegetation (trees,
shrubs, grass) that
are established for
one or more
environmental and
economic purposes.
Windbreaks
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What are the benefits?
Reduce soil erosion
 Protect plants
 Enhance plant growth
 Manage snow
 Provide shelter
 Reduce energy needs
 Improve wildlife
habitat
 Enhance aesthetics
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Windbreaks
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Moderate noise
Screen views
Reduce airborne
chemical drift
Improve irrigation
efficiency
Increase carbon
storage
Mitigate odors
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How does a windbreak work?
Modify:
Trap/filter air borne:
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Windbreaks
Air flow
Sound waves
Odor plumes
Microclimate
dynamics
Sediment
Snow
Nutrients
Pesticides
Pathogens
VOCs
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What are the effects?
Windbreaks:
 lower wind velocity causing
air-borne material to be deposited
 physically trap air-borne material
 adsorb some of the chemicals
attached to air-borne material
 alter the microclimate on the downwind
side of the windbreak
Windbreaks
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How can air flow patterns be modified?
Modification of the wind depends upon six
key windbreak features:
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Height
Density
Orientation
Length
Width
Continuity
Windbreaks
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Why is height important?
H = Effective height
of the windbreak
 The height
determines the
distance of the
downwind sheltered
(protection) zone

10H to 15H
Windbreaks
H
10H to 15H
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Why is density important?
Dense: maximum wind
reduction but short wind
shadow
 Moderately dense: less
wind reduction but
longer wind shadow
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Why is orientation important?
Location or layout:
 Directly influences area
protected
 Effects vary with critical
weather periods and
wind directions
Wind Rose
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Why is length important?
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For full protection, the windbreak needs to extend
the entire length of the area needing protection to
account for changing wind directions.
Doubling the length of a windbreak will generally
increase the area protected by 4 times
Windbreak
protected area
Windbreaks
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Why is width important?
Width influences:
 Density
 Wildlife values
 Trapping capacity
and efficiency
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Why is continuity important?
Wind speed increases in a gap
 Gaps in the windbreak can result in
damage or complications downwind
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Windbreaks
(% of open wind speed)
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Types of windbreaks
Windbreaks
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Types of windbreaks: field
Windbreaks
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Types of windbreaks: farmstead
Windbreaks
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Types of windbreaks: livestock
Windbreaks
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Types of windbreaks: specialty
Living
Snow
Fence
Irrigation
efficiency
Dust
Windbreaks
Odor
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Multi-purpose windbreaks
Bio-energy feedstock
 Food security
 Wildlife
 Income products
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Summary
Windbreaks are an agroforestry practice
 Windbreaks provide multi-functional
benefits
 Windbreaks can be designed to meet
site needs and land owner objectives
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Windbreaks
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For Additional Information
A number of web sites are available to provide more detailed
information on windbreaks. Here are a few:
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USDA National Agroforestry Center
http://www.unl.edu/nac/windbreaks.htm
The Center for Agroforestry
http://www.centerforagroforestry.org/practices/wb.php
Association for Temperate Agroforestry
http://www.aftaweb.org/entserv1.php?page=1
USDA Natural Resources Conservation Service
http://www.nrcs.usda.gov/wps/portal/nrcs/home
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Acknowledgements
This presentation was developed by the USDA
National Agroforestry Center (NAC), Lincoln NE.
NAC is a USDA partnership between the U.S.
Forest Service and the Natural Resources
Conservation Service.
National
Agroforestry
Center
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A partnership of:
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