Agroforestry

Wood is one of the oldest 

sources of renewable 

energy, and woody crops are 

part of the solution to America’s 

growing energy needs. 

 As our nation’s energy supply 

continues to emerge as a key 

21st-century issue, the use of 

woody crops for biofuels, 

bioenergy and bioproducts is 

becoming a necessity. 

 Agroforestry systems can 

support agriculture and rural 

economies by reducing energy consumption, creating a 

potential source of renewable 

energy and generating an energy 

product to be sold to diversify 

and increase income. 

In addition, Working Trees for 

Energy sequester carbon, which 

helps to mitigate the effects of 

climate change and greenhouse 

gases. 

 The right tree in the right 

place provides wind protection, 

shade and cool air, while adding 

beauty, privacy, income and 

wildlife habitat to the landscape. 

 Working Trees for Energy can 

be incorporated into windbreaks, 

silvopasture, alley cropping, 

forest farming and riparian 

forest buffers.

 Working Trees for Energy

explains how trees and shrubs 

can simultaneously provide 

an energy source, an income 

stream for farms, woodlands, 

ranches and nearby communities, as well as environmental 

benefits.

Using proven 

agroforestry 

practices, 

Working Trees 

for Energy can 

help farms, 

ranches and 

communities 

reduce 

energy use, 

diversify 

sources 

of income and 

provide 

environmental 

benefits.

Working Trees

for Energy
 Agroforestry Practices for Energy

Windbreaks are rows of vegetation used to reduce and redirect wind.

Windbreaks can be designed to provide 

energy savings for a small residential 

lot, a farmstead or an entire housing 

development.

A well-designed windbreak can 

reduce the amount of energy needed 

to heat and cool a home or dwelling, 

reducing energy costs as much as 20 to 

40 percent.

Field windbreaks improve crop 

yields, reduce energy inputs, increase 

water-use efficiency and reduce wind 

erosion. Most crops produce higher 

yields and better quality products when 

protected from the negative effects of 

winds.

Living snow fences keep roads clear 

of drifting snow, increase driving safety 

and reduce road maintenance costs. By 

reducing or eliminating the need for 

snow removal, significant energy savings are realized.

A multi-row windbreak planting 

can be designed to function as both 

a windbreak and a source of woody 

biomass for energy needs and products. 

In this case, additional rows need to be 

incorporated into the design to allow 

rotational harvesting while maintaining 

the design integrity of the windbreak.

Riparian forest buffers protect water 

quality by intercepting and filtering 

pollution from agricultural runoff. 

In addition, these buffers stabilize 

streambanks while providing a source 

of supplemental income. 

A riparian forest buffer typically 

requires rows of trees and shrubs along 

the water body. Usually three to five 

rows of trees are established. In order 

for a riparian forest buffer system to 

be effective for both biomass production and environmental protection, a 

minimum of seven woody rows may 

be necessary. If biomass harvesting is 

planned, the basic design integrity of 

the buffer must be maintained. 

Therefore, as one or more rows are 

harvested for biomass or fuelwood, the 

remaining rows would be left in place 

as a riparian buffer until the previously 

harvested row(s) have regrown and are 

tall enough to be effective as a buffer. 

Another benefit of harvesting some 

trees is the removal of trapped nutrients 

from the floodplain so they cannot be 

reintroduced into the stream. More 

growing time may be necessary to ensure adequate tree height and size.

 

In forest farming, high-value 

specialty crops are cultivated under 

the protection of a forest canopy that 

has been modified to provide a desired amount of shade. Forest farming 

provides an added income while trees 

are being grown for wood products and 

energy use.

Properly managed, forests can be 

improved to provide not only quality 

timber and wildlife benefits but also 

fuelwood. With the growing popularity 

and economic benefits of using wood 

as a partial or total energy source, 

harvesting and gathering fuelwood has 

become a way of life and a source of 

income for many. Estimates indicate 

that an average woodlot in the Midwest contains approximately six cords 

of hardwood fuelwood per acre that 

can be harvested while improving the 

overall forest health. 

Trees, like other crops, need room 

to grow. Too many trees on an acre 

of land will cause reduced growth 

rates due to competition for sunlight, 

nutrients and water. Periodic thinning 

(selective removal of trees) of these 

stands will create more space for the 

better formed, more desirable trees and 

improve stand growth. Thinning also 

will increase the supply of fuelwood 

for use in the home or to be marketed 

and sold as forest products.

A Windbreaks B Riparian Forest Buffers C Forest Farming
A

Want more information?

 Agroforestry: Making a Difference

Forest Products Lab/USDA Forest Service — Primer for Woody Biomass

http://www.fpl.fs.fed.us/products/publications/pubs_specified_topic.php?groupings_id=56&sort_

criteria=title

National Association of Conservation Districts’ Biomass Desk Guide

http://www.nacdnet.org/resources/guides/biomass/

Department of Energy Biomass Program Resources

http://www1.eere.energy.gov/biomass/index.html

eXtension Woody Biomass Community of Practice

http://www.extension.org/pages/26594/wood-energy-community-of-practice

Forest Products Fuel Value Calculator

http://www.fpl.fs.fed.us/documnts/techline/fuel-value-calculator.pdf

Local Assistance from USDA, use the USDA Service Center Locator

http://offices.sc.egov.usda.gov/locator/app

Find Your State Forester

http://www.stateforesters.org/about_nasf

D

E

C

F

B
Silvopasture systems combine trees, 

forage and livestock production. Trees 

are managed for long-term, high-value 

timber and the understory is managed 

for forage production to support livestock grazing.

Silvopasture systems could be established with multiple rows that would 

allow periodic harvests for shorter 

rotation biomass or for energy, while 

keeping the integrity of the system by 

retaining specific rows or trees for longer rotation forest products and shade.

Using the silvopasture alleyways 

between the tree rows for energy production can be another energy option 

when a viable local biomass market is 

available. Planting productive forages 

like switchgrass can add flexibility to 

a silvopasture. When biomass prices 

are high or livestock prices are low, 

grazing can be stopped and the forage 

could be managed for biomass production for a few years.

In an alley cropping system, an agricultural crop is grown in the alleys between widely spaced rows of trees. The 

agricultural crop provides for an annual 

income and the trees can produce a 

long-term or supplemental income. 

When planted in alley cropping systems, woody perennial biomass crops 

can provide feedstocks that support 

the development of alternative energy 

industries or on-farm uses, while providing ecosystem services and creating 

sustainable farming systems.

Recently, there has been interest in 

using alley cropping for short-rotation, 

woody species such as willow. The 

same impacts on microclimate found 

with windbreaks and annual crops are 

at work with shrub and tree crops. Results indicate that hardwood alley cropping is a viable alternative to a single 

species, short-rotation block planting.

Working Trees for Energy can be 

used to help deal with both current 

and future resource challenges such as 

bioenergy feedstock needed for renewable energy enterprises. Fast growing 

trees, known as “short-rotation, woody 

crops,” can be intensively managed for 

energy biomass production in multiple 

rows or large blocks or incorporated 

into agroforestry practices as an added 

use and benefit. 

Producing direct revenues or incorporating the woody bio-feedstock into 

on-farm uses reduces overall financial 

risk due to fluctuating prices of fossilbased fuels. The sale of biomass feedstocks is best suited for areas where 

there are strong markets for feedstocks. 

Very small plantings of 10 acres or 

less may not be financially attractive to 

contractors or buyers if they are located 

more than 50 miles from the utilization source. On-farm or on-ranch uses 

would not have this restriction.

Silvopasture Alley Cropping Special Applications

 Agroforestry Practices for Energy

D E F
Energy Conservation

 Working Trees for Energy can reduce energy consumption on the farm, on the ranch and in communities. Working Trees for Energy absorb water through their roots and 

release moisture through the leaf surfaces by a process 

called evapotranspiration, which cools the air in much the 

same way our skin cools us through sweating, saving energy 

in several ways. 

 Carefully positioned trees can save up to 25 percent of a 

household’s energy needs for heating and cooling. Trees can 

block cold winter winds that can enter buildings through 

small openings and carry heat away from outer surfaces of 

buildings. Shade from trees reduces air conditioning needs 

and makes non-air conditioned homes more comfortable. 

An air conditioner’s efficiency can be increased by as much 

as 10 percent when shaded by trees. 

Communities with unshaded paved streets and parking 

lots are sometimes referred to as “heat islands,” which are 

much warmer than the surrounding areas. Trees that shade 

paved areas like driveways and parking lots will greatly 

decrease surface heat, saving energy and money. Tree leaves

also absorb light energy, thereby reducing reflected heat.

 Working Trees for Energy can be a source of energy for 

on-farm operations or personal use. Growing trees for 

fuel is one option to supplement energy needs in the years 

ahead. Local utilization of fuelwood limits the risk of 

spreading invasive pests. Growing woody plants for commercial energy supplies also has merit, as does providing an 

alternative fuel for small-scale heating applications on-site 

or in community facilities. The advent of efficient wood 

burning stoves and boilers makes wood energy an attractive 

alternative energy source. 

Although Working Trees for Energy are often viewed in 

the landscape as just a conservation practice, they are much 

more. They are productive conservation. All agroforestry 

practices can be designed and utilized for periodic harvesting of a portion of the trees and shrubs for energy. 

 Working Trees for Energy can be sold as raw material for 

energy conversion. Wood fuel products include firewood, 

charcoal, chips, pellets and sawdust. The particular form 

used depends upon source, quantity, quality and application. The use and demand for plant biomass will continue 

to grow as both domestic and global populations seek 

renewable energy stocks that support local jobs and rural 

economies. Agroforestry practices have the potential to 

provide large quantities of biofuel feedstock, while providing valuable ecosystem services and helping to build the 

vitality of rural economies. The amount of biofuel that can 

be sustainably produced each year is potentially very large. 

Woody biomass can be used for electrical power and heat 

generation. Combined heat and power units are a more 

efficient use of fuel than a single purpose power application. 

 In addition, Working Trees for Energy are well suited for 

the future of biorefining that creates liquid fuels such as biooils, ethanol, methanol and other bioproducts.

Energy Source

Energy Products
Glossary of common bioenergy terms

Bioenergy — Useful, renewable energy produced from organic 

matter — the conversion of the complex carbohydrates in organic 

matter to energy. Organic matter may either be used directly as a 

fuel, processed into liquids and gases or be a residual of processing and conversion. 

Biogas — A gas produced from biomass, usually combustible.

Biomass — Organic matter available on a renewable basis. 

Biomass includes forest and mill residues, agricultural crops and 

wastes, wood and wood wastes, animal wastes, livestock operation residues, aquatic plants, fast-growing trees and plants, and 

municipal and industrial wastes.

Biorefinery — A facility that processes and converts biomass into 

multiple value-added products. These products can range from 

biomaterials to fuels such as ethanol or important feedstocks for 

the production of chemicals and other materials. Biorefineries can 

be based on a number of processing platforms using mechanical, 

thermal, chemical and biochemical processes. 

British thermal unit (BTU) — A standard unit of energy equal to 

the heat required to increase the temperature of 1 lb (0.45 kg) of 

water 1°F (0.56°C).

Carbon sequestration — Carbon sequestration is the process by 

which atmospheric carbon dioxide is absorbed by trees and other 

plants through photosynthesis and stored as carbon in biomass 

(trunks, branches, foliage and roots), soil and wood products. 

Adopting certain agricultural and forestry activities can reduce 

greenhouse gas (GHG) emissions to the atmosphere and sequester 

additional carbon. 

Char — Carbon-rich combustible solids that result from pyrolysis 

of wood in the early stages of combustion. Char can be converted 

to combustible gases under certain conditions or burned directly. 

Cofiring — Utilization of bioenergy feedstocks as a supplementary energy source in high-efficiency boilers.

Cogeneration — Combined heat and power (CHP). 

Combined heat and power (CHP) — The waste heat from producing power is used for thermal needs.

Ecosystem services — Benefits people obtain from ecosystems. 

These include provisioning services such as food, water, timber 

and fiber; regulating services that affect climate, floods, disease, 

wastes and water quality; cultural services that provide recreational, aesthetic and spiritual benefits; and supporting services such as 

soil formation, photosynthesis and nutrient cycling. 

Energy conservation — Efforts made to reduce energy waste. 

Energy conservation can be achieved through increased efficient 

energy use, in conjunction with decreased energy consumption, 

which can result in increased financial savings, environmental 

quality and human comfort.

Energy conversion — Converting one type of energy into another. Changing the energy stored in wood into heat by burning it 

is one example. A wind turbine changing wind energy to electrical 

energy is another.

Feedstock — Any biomass resource destined for conversion 

to energy, or to another form such as fuel or bioproducts. For 

example, corn is a feedstock for ethanol production. Soybean oil 

may be a feedstock for biodiesel or for bioproducts such as inks, 

paints, coatings and other bioproducts. Cellulosic biomass has potential to be a significant feedstock source for biofuels, biopower 

and bioproducts.

Pyrolysis — A process of reduction at oxygen-starved conditions, 

involving the physical and chemical decomposition of solid organic matter by the action of heat into liquids, gases and a carbon 

char residue.

Short-rotation woody crops — Fast, growing tree crops that are 

grown primarily for their fuel value. 

Woody biomass — Trees and woody plants, including limbs, 

tops, needles, leaves and other woody parts, grown in a forest, 

woodland or rangeland environment that are the byproducts of 

management. 

Wood gasification — The process of heating wood in an oxygenstarved chamber until volatile pyrolysis gases (e.g., CO, H2

, 

O2

) are released from the wood. The gases emitted are low- or 

medium-energy-content gases that can be combusted or used to 

produce chemicals.

A partnership of

Contact: USDA National Agroforestry Center, 402.437.5178 ext. 4011, 1945 N. 38th St., Lincoln, Nebraska 68583-0822. www.unl.edu/nac

The USDA National Agroforestry Center (NAC) is a partnership of the Forest Service (Research & Development and State & Private Forestry) and the Natural 

Resources Conservation Service. NAC’s staffs are located at the University of Nebraska, Lincoln, NE and in Blacksburg, VA. NAC’s purpose is to accelerate 

the development and application of agroforestry technologies to attain more economically, environmentally, and socially sustainable land use systems by 

working with a national network of partners and cooperators to conduct research develop technologies and tools, establish demonstrations, and provide 

useful information to natural resource professionals.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, 

and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or 

because all or part of an individual’s income is derived from any public assistance. (Not all prohibited bases apply to all programs.) Persons with disabilities 

who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at 202-

720-2600 (voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, 1400 Independence Avenue, SW, Washington, DC 20250-9410 or call toll free 

866-632-9992 (voice). TDD users can contact USDA through local relay or the Federal relay at 800-877-8339 (TDD) or 866-377-8642 (relay voice). USDA is 

an equal opportunity provider and employer.

Natural Resources 

Conservation Service

First edition February 2012

This brochure was produced with valuable assistance from the Forest Products Laboratory, U.S. Forest Service.