N a t i o n a l A g r o f o r e s t r y C e n t e rAgroforestry

Fall 2001 / Winter 2002

see DESIGN on page 9

Considerations for Designing an Alley

Cropping Practice

Alley cropping is broadly defined as the

planting of single or multiple rows of trees

into a field of crops or forage. The tree rows

create protected alleys for the agricultural or

horticultural crops.

Role on the farm

There are numerous roles that alley cropping

can play on a farm or acreage:

 Diversify farm products –Alley cropping

provides the opportunity to grow wood or other

tree products such as nuts or fruit, while producing annual income through companion crops.

 Supplement income – Timber and nontimber products may contribute to income

generation. In addition to the potential for

producing nuts, berries, and fruits, well-managed timber can provide a long-term timber

investment.

 Reduce soil erosion from wind and water

– Soils with a high erodibility index (greater

than eight) are susceptible to damage and are

difficult to protect when managed as cropland. Alley cropping protects fragile soils

through a network of tree and grass roots and

supplemental ground cover resulting from

fallen leaves and the companion crop. Rows

of trees, shrubs, and/or grasses planted on the

contour of a slope will also serve to reduce

soil movement down the slope. Wind speeds

can also be reduced with beneficial effects

similar to that of field windbreaks.

 Improves Soil – Alley cropping can reduce

crop evapotranspiration by 15 to 30 percent

and increase water content in the tillage layer

by five to 15 percent. Deep tree roots trans- 10

ALLEY CROPPING

5

Inside

20/20 VISION FOR FARMING’S FUTURE

This issue of Inside Agroforestry highlights the potential of alley cropping

practices to diversify and improve farm economics. As you read

this issue, think of innovative landowners who you can talk to who

might benefit from alley cropping’s versatility.

6-7

Inside 

ANOTHER WAY TO 

COMBAT SOIL EROSION

TIMBERBELTS:

A NEW LOOK AT WINDBREAKS

ALLEY CROPPING = 

ECONOMIC DIVERSITY

4 MIXING IT UP:

CHRISTMAS TREES &

BLACK WALNUT
Alley Cropping: 

An Underutilized Option

NAC Director’s Corner

A commentary on the status of agroforestry 

by Center Director, Dr. Greg Ruark

On the farm making a living from year to year is fraught

with uncertainty. Success depends on weather conditions and favorable markets at harvest. Alley cropping

systems provide a way to lower risk by diversifying production. In alley cropping an agricultural crop is grown in the

“alley” formed between tree rows. This provides for the generation of annual income from agricultural crops, while the

tree crop is managed as a long-term economic investment. An

attractive feature of installing alley cropping is that it allows a

landowner to gradually transition a field into an alley cropping system, while continuing to crop most of the field area

each year. 

Traditionally, fine quality hardwoods such as walnut,

pecan, and oaks have been preferred species, as they can be

managed to produce high-value lumber or veneer logs. More

recently, fast-growing hybrid poplars (mainly cottonwoods)

are being grown for pulpwood or even sawtimber where wood

markets exist. When nut-bearing trees are used, they can provide an intermediate product for sale in as little as seven to ten

years. In addition to improving annual cash flow, these systems can also protect annual crops from wind, reduce soil erosion, and provide wildlife habitat. Most row, grain, and forage crops, as well as specialty crops, such as catnip or St.

John’s Wort, have been shown to grow well in alley cropping

systems. The type of agricultural crop grown will vary over

time as the trees mature and produce more shade.

Two years ago the National Association of Resource

Conservation and Development (RC&D) Councils conducted

a national survey of agroforestry. Although 22 states were

reported to be using alley cropping systems, it was found to be

the least pervasive of the agroforestry practices. It was most

commonly encountered east of the Mississippi River, although

several states in the Great Plains and the Northwest were also

using the practice. The main motivation reported for adopting

alley cropping was to improve farm economics. Other reasons

included controlling field erosion, improving water quality,

and providing wildlife habitat. Typically, hardwood tree

species are being used in single and multiple row arrangements, but some locations do employ softwoods. The survey

concluded that the greatest impediments to further adoption of

the practice were the lack of knowledge by natural resource

professionals and landowners and the need for more localized

demonstrations that illustrate the practice and document

economic returns.

2 Inside Agroforestry | Fall 2001 / Winter 2002

Agroforestería por Dentro, Verano 1998

Inside Agroforestry, Summer 1998

Árboles Trabajando en Beneficio de la Agricultura

Working Trees for Agriculture

Árboles Trabajando en Beneficio de la Ganadería

Working Trees for Livestock

Árboles Trabajando en Beneficio de la Ganadería -

Agroforestería: Silvicultura en el Sureste de los EE. UU.

Working Trees for Livestock -

Agroforestry: Silvopasture in the Southeast

Notas de Agroforestería Agroforestry Notes

#8 Silvopastoreo: Una práctica agroforestal

Silvopasture: An Agroforestry Practice

#9 Biología Silvopastoril

The Biology of Silvopastoralism

#18 De un Bosque de Pino hacia un Sistema Silvopastoril

From a Pine Forest to a Silvopasture System

#22 De sistemas Pastoriles a Silvopastoriles

From a Pasture to a Silvopasture System

New in 2002! Selected NAC Publications have been translated into Spanish
Fall 2001 / Winter 2002 | Inside Agroforestry 3

Gene Garrett, Director, University of

Missouri, Center for Agroforestry

Agroforestry and Alley Cropping:

see OPPORTUNITIES on page 10

Opportunities for the 21st Century and Beyond

Agroforestry has an important role to

play in revitalizing rural America. Both the

need and opportunities for agroforestry are

overwhelming.

Historically, much of North America

was covered with forests. However, with

the increasing demand for building materials and agriculture in the late 1800s and

early 1900s, our forested acres declined.

Forest area in the US has remained relatively consistent since the 1930s but recently

we have begun to again see a reduction in

forest acreage as development pressures

have increased. Many in our society, for

reasons of resource, economic, environmental, and social considerations, would like to

see a stronger transition from conventional

cropping systems to combinations of croplands and forests or permanent forests on

much of our marginal and less productive

agricultural lands. A conversion of this

magnitude, however, requires an economic

justification. The returns on conventional

forestry practices typically are not enough

in many regions of the US and Canada to

serve as an inducement to farmers and other

landowners to make this conversion.

Never before in the history of North

American agriculture has the opportunity

for agroforestry adoption been greater. As

part of an ecologically-based land management system, agroforestry can contribute

substantially to generating the ecosystem

diversity and processes that are so important to long-term sustainability and profitability. In contrast to the industrial agriculture/forest management models that have

dominated development through the 1990s

and are now being challenged due to high

environmental costs and the degradation of

rural economies, agroforestry offers a more

holistic land-use management model for the

21st century and beyond. However, it is a

model that requires a shift in our thinking

and perspective, and demands skills in managing rather than reducing complexity. It

challenges us to transcend disciplinary

boundaries and explore the potential synergisms created from synthesizing, integrating

and diversifying landscapes. When properly

applied, the agroforestry model can meet

the specific needs of the landowner and

society while preserving the integrity, stability, and beauty of the family farm. At a

time when rural America is looking for

alternatives to “help pay the bills” and a

shortfall is predicted for wood production in

the US this match appears to be natural.

Alley cropping, an intensive land-management program that optimizes the benefits from the biophysical interactions created when trees and/or shrubs are deliberately

combined with crops, provides a means of

integrating land-use management systems

When properly applied, alley cropping can help meet specific needs of a landowner while at the same time preserve the integrity, stability, and beauty

of the family farm.
Close-up of black walnut

trees (left). Black walnut

trees being “trained” to

grow straight for an eventual high-value lumber

crop next to Douglas fir

Christmas trees (right).

4 Inside Agroforestry | Fall 2001 / Winter 2002

Are Joe and Stan Low of Beavercreek,

Oregon mainly Christmas trees growers or

black walnut growers? The answer is both,

but the question stirs an amicable, on-going

debate between father and son. Forestry, agriculture, and agroforestry all coexist profitably

on their 900 acre Highland Farm in the northern Willamette Valley. 

A native of West Virginia, Joe learned

the value of black walnut timber during the

Depression years. After moving to Oregon in

1943, he began a 30-year career in the

sawmilling business, primarily cutting native

Douglas fir in the local area. But, his interest

in black walnut remained, prompting him to

plant some of Oregon’s first stands of walnut

for timber 35 years ago. Over the past 20

years, Joe and his son Stan have established

over 200 acres of black walnut/Christmas tree

alley cropping - or vice versa.

“I planted almost every tree on the

place,” Joe said, referring to the 50,000 black

walnuts now growing on Highland Farm.

“Timber has always been my business and

I’m serious about walnut timber.”

In Joe’s experience, eastern black walnut

grows well in the Willamette Valley. The

only disease he has encountered is walnut

anthracnose, but he says it is less of a problem

in Oregon than in the warm humid climates

of the Midwest. Weed control is the main cultural practice, Joe said, along with training

during the early years of establishment to correct stem form deficiencies.

At Highland Farm, black walnuts are

planted on a 15 X 15 foot spacing (about 200

trees per acre) with either Douglas fir or noble

fir as the short-rotation intercrop. About 25

years after planting, Joe plans to thin the walnut to a final crop spacing of 30 X 30 foot.

(about 50/ac). His aim is to produce a straight,

four foot diameter log in about 75 years that

will yield high-value timber or veneer.

Fast-growing and commercially-valuable

Douglas fir is co-dominant with walnut and

serves as a “crowd tree” to force the walnut to

produce tall, straight stems. In stands where Joe

has simultaneously planted walnut and Douglas

fir at the same initial spacing (200 trees per

acre), he will be able to choose at the time of

first thinning whether to leave the walnut or the

Doug fir to grow as the final timber crop. 

In some stands, Joe has interplanted the

relatively-slower growing but more valuable

noble fir, planted on 5 X 5 foot. spacing, with

walnut on 15 X 15 foot. centers. Noble fir is

ready for harvest as Christmas trees in eight

to10 years, compared to about seven years for

Douglas fir Christmas trees.

In all of his plantings at Highland Farm,

Joe has planted nuts rather than seedlings.

Experience has shown him the importance of

direct seeding to develop a strong taproot that

will produce hardy trees better able to cope

with Oregon’s dry summers. Joe has scouted all

the best walnut trees in the local area and each

year collects nuts from selected trees for planting. He either plants the nuts in the fall or stratifies them during the winter for spring planting.

The alley cropping enterprise at

Highland Farms is a good example of the

extra management and economic tradeoffs

inherent in agroforestry versus monoculture.

According to Stan, who manages the

Christmas tree operation, there is an economic cost to alley cropping. Labor costs to shear

Christmas trees intercropped with black walnut are higher because extra care and time

must be taken to avoid damage to the walnut.

Weed control during the early years of establishment is also more problematic when firs

and walnuts are mixed.

As the walnut trees mature, they compete

for light with the Christmas trees. Stan has

observed that shade will degrade the needle

length and color of the firs compared to opengrown trees, and therefore decreases their

quality and potential price as Christmas trees.

He suggests that increasing the initial

spacing of the walnuts would help overcome

these problems. If the walnuts were planted at

15 X 20 or 25 feet, in every fourth or fifth

row instead of every third row, the firs would

have more available light and develop into

higher quality Christmas trees. Shearing costs

would also be reduced, he said, by allowing

more space for the firs.

Whatever they decide for initial spacing

and management, it is obvious that the Lows

have a very large resource of valuable hardwood timber slowly maturing to harvest age.

Joe anticipates that this resource will create

markets for his timber both locally and overseas, especially in Europe. There will also be

a substantial nut crop that could be processed

on-site or shipped to processors in California.

Joe is also thinking about other potential

intercrops that could be produced among his

black walnuts after the Christmas trees are

harvested. After canopy closure occurs, he

said that ginseng could be cultivated under

the trees in a forest farming regime. 

Reprinted from The Temperate Agroforester, (AFTA), April 1998 (Vol. 6, No 2).

Miles Merwin, President, Association for

Temperate Agroforestry (AFTA)

The alley cropping 

enterprise at Highland Farms

is a good example of the extra

management and economic

tradeoffs inherent in agroforestry versus monoculture. 

Oregon Family Farm Mixes 

Christmas Trees and Black Walnut
Fall 2001 / Winter 2002 | Inside Agroforestry 5

see POPLAR on page 11

Stop Soil Erosion

with Alley Cropping

the contour with a vegetative barrier or into a

wider strip of grass as with a contour buffer

strip. The tree/grass combinations in a contour

buffer strip can vary in width along the length

of the strip to accommodate the natural lay of

the land thus eliminating small odd areas that

would be difficult to crop. The tree/grass strip

should not be less than 30 feet in width. The

width of the agricultural crop strip is constant

for the entire strip length and is determined by

farm machinery widths and the maximum

slope distance allowable to control erosion

and water borne contaminants. With these

width guidelines, the agricultural crop will not

experience production losses from tree competition throughout the entire length of the

tree rotation.

Two demonstrations have been established in Iowa using this approach. The

tree/grass strips contained three to four rows

of trees with the outside rows being conifers

S

oil erosion from water on sloping land

continues to be a significant concern for

many agricultural producers in the

United States. Many different soil conservation practices are applied to reduce this soil

erosion including conservation tillage, terraces, contour strip cropping, contour buffer

strips, vegetative barriers, and others. These

practices are usually applied in different combinations with crops to form a conservation

cropping system. One variation to these traditional approaches is alley cropping, where an

agricultural crop is grown simultaneously

with a long-term tree crop to provide annual

income while the tree crop matures. 

The spatial arrangement of the trees in

an alley cropping system depends on the

landowner’s objectives. For example, if the

landowner wants to reduce erosion and continue to grow agricultural crops for a long

period, the alley cropping system can be configured similarly to contour strip cropping. In

this case the trees and/or shrubs ae planted on see EROSION on page 11

Soil erosion, as seen below,

can be reduced with alley

cropping. Trees in an alley

cropping system take up

excess water and create a

stable zone of permanent

vegetation, while at the same

time provide economic and

conservation benefits. 

Photo courtesy USDA NRCS
BUILD

H O W T O

6 Inside Agroforestry | Fall 2001 / Winter 2002

ECONOMIC DIVERSITY

ning horizon may be as long as sixty years

when the trees are taken into consideration.

Furthermore, because of the long planning

horizon of alley cropping, many of the revenues and costs do not occur at regular or

predictable intervals throughout the entire

planning horizon.

Additionally, because alley cropping typically incorporates a fixed tree component

with a crop or livestock component, the crop

or livestock component may change over

time. For example, an alley cropping practice

may start out as soybeans grown between

rows of eastern black walnut trees, but by the

time the trees are producing nuts, hay may be

the crop grown between the rows of trees

because a more uniform surface is required to

harvest the nuts.

These characteristics of alley cropping

practices require a specific type of budgeting

method that will be flexible enough to allow

for variable crop and/or livestock components, as well as being comprehensive

enough to show annual cash flows for the

entire planning horizon.

Budgeting

Budgeting is a two-step process:

 Develop enterprise budgets

 Combine the enterprise budgets into a

cash flow plan.

An enterprise budget is simply a comAlley cropping can be economically

attractive for some landowners in that

it provides a strategy for economic

diversification where long-term income from

trees is combined with continued annual

income from cropping or livestock. However,

before venturing into alley cropping its economic aspects should be evaluated to provide

a basis for estimating financial needs and feasibility, highlights trade-offs between multiple

benefits, and monitors economic efficiency. 

Unique Characteristics of Alley

Cropping:

 Long planning horizon

 Irregular occurrences of costs and revenues

 Fixed tree component with variable crop

or livestock component

The main technique used in economic

analysis is budgeting. Economic budgeting is

a very flexible process. Alley cropping, however, poses some unique budgeting problems

because it involves multiple enterprises with

varying production cycles.

Unlike most agricultural commodities,

alley cropping has a “planning horizon” of

greater than one season due to the tree component. A “planning horizon” is simply the

time period in which all costs and revenues

for a given practice are realized. For soybeans, a planning horizon may be six months

to a year. For alley cropping, a simple planAdapted From:

Economic Budgeting

for Agroforestry

Practices. By Larry

D. Godsey, University

of Missouri, Center

for Agroforestry.

March 2000.

Rows of trees create a productive

environment for irises, while at the

same time produce a tree crop of nuts

or wood chips as pictured above.

A L L E Y

C R O P P I N G

with
Fall 2001 / Winter 2002 | Inside Agroforestry 7

plete, detailed listing of all the costs and revenues expected for each single enterprise,

such as corn, livestock, or trees. A cash flow

plan combines the details from the different

enterprise budgets in an alley cropping practice and adds a time dimension. The enterprise

budget provides a framework for reporting

and monitoring the profitability of each enterprise, and the cash flow plan provides the

information necessary to assess and forecast

the economic feasibility of the alley cropping

system over time.

Developing the Enterprise Budgets

The development of an enterprise budget is a

three-step process:

 List all possible sources of revenue for an

enterprise.

 List all possible sources of variable costs. 

 List all possible fixed costs.

For the tree component of an alley cropping system it is important to list not only the

sources, but also list the timing of revenues.

For example, an alley cropping practice with

eastern black walnut trees may receive CRP

payments for the first 15 years of the planning

horizon but not after that period. Income from

nut production may start at year ten or twelve

and continue until the tree is harvested for

wood in year fifty-five or sixty.

Variable costs are those costs attributed

to the productive use of resources. Variable

costs can be grouped into cash and non-cash

costs. Variable cash costs include payments

for establishment, maintenance, harvesting,

and marketing. Variable non-cash costs do

not require a cash outlay, but reflect opportunity costs. Opportunity cost is simply the

value of the next best alternative that is not

chosen. For example, labor supplied by family members may not require a cash outlay,

but should still be considered in the economic

analysis since the opportunity to do something else is expended.

The third and final step to preparing an

enterprise budget is to list all fixed costs.

Fixed costs are typically those costs that are

attributed to resource ownership. Fixed costs

occur regardless of any productive activity

being attempted. Fixed cash costs usually

include property taxes, insurance, interest on

intermediate or long-term debt, and lease

agreements. Fixed non-cash costs are important when developing an investment analysis,

because these costs have significant influence

on taxes. However, these costs are difficult to

determine. Depreciation and land costs are

the two main areas of fixed non-cash costs.

From Enterprise Budgets to Cash

Flow Plans

Once enterprise budgets are developed, a cash

flow plan for the alley cropping practice can

be developed. A well-established alley cropping practice may combine a tree enterprise

with a hay and livestock enterprise. As mentioned earlier, often times the tree enterprise is

constant while the crop or livestock enterprises vary over time. Cash flow planning has two

major benefits for agroforestry economic

analysis: 1) a cash flow plan allows for multiple enterprises to be considered; and 2) a cash

flow plan incorporates a time dimension.

Using a cash flow plan in conjunction

with enterprise budgets can simplify the

process of economic analysis by allowing the

enterprise budgets to reflect the detailed information, and the cash flow plans reflect a

broader economic picture. In this way the producer can compare resource management

alternatives to determine the one that best

meets management goals.

Reassessment

Economic analysis is not meant to be, nor is it

designed to be, a one-time activity. It is

designed to be a roadmap for a dynamic and

living system. Reassessment takes the information gathered in the economic analysis and

combines it with other information to change

the original goals or fine-tune the design so

that it is more successful at meeting those

goals. Reassessment is the continuous loop

that helps redefine goals, adjust designs, and

modify indicators. Economic analysis is just

one part of the reassessment loop. 

A black walnut/forage alley cropping system can produce hay, nuts, firewood from thinnings, and eventually high-value walnut lumber or veneer.
double the area protected from wind. In dry years, crop

yields in these adjacent protected areas can be expected to be

10 to 20 percent greater than in unprotected fields, resulting

in greater whole farm profitability. In addition, the trees are

slated for harvesting in six to eight more years, and are

expected to produce 35 cords (128 cubic feet) of wood per

acre, worth $1,400 per acre at today’s stumpage prices

(approximately $40 per cord). 

Timberbelts can improve net farm income, sequester carbon, enhance wildlife habitat, and improve water quality.

They serve as windbreaks to reduce soil erosion, increase

crop yields, and improve public safety through enhanced

snow management. Other benefits include diversifying farming systems and agricultural landscapes, improving soil quality, reducing the input and transport of agricultural chemicals

and fertilizers, and improving local air quality. Because they

both protect adjacent crops from the wind and produce wood products, timberbelts are an agroforestry

practice that becomes a new profit center for the farm.

8 Inside Agroforestry | Fall 2001 / Winter 2002

Scott J. Josiah

Extension Forester, University of Nebraska-Lincoln

Timberbelts are multiple row windbreaks that are planted with commercially valuable, fast growing trees to produce

wood products. Timberbelts are a good example of “productive conservation,” that is, a conservation practice that creates

a new source of income, while improving the crop environment and protecting and conserving resources. 

A network of four-year-old experimental hybrid poplar

(cottonwoods) timberbelts of varying widths (two to 14

rows) in west-central Minnesota are demonstrating the

power of this concept to quickly provide wind protection

over large areas, as well as to produce large amounts of salable wood fiber. Trees growing on the better soils, without

supplemental irrigation, average 29 feet tall and four inches

in diameter at breast height (4.5 feet above the ground).

These timberbelts are providing substantial wind protection

15 times the height of the trees or nearly 450 feet into the

adjacent fields. It would take more traditional windbreak

species (green ash, eastern red cedar, and pine) up to 20 years

to provide similar levels of protection. These timberbelts are

expected to reach 60 feet in height in six years, which will

Holding Up the Farm

TIMBERBELTS

Above: Timberbelts can create a new source of wood-based

income, while enhancing the crop environment, and protecting

and conserving natural resources. 
Design

continued from page 1

Fall 2001 / Winter 2002 | Inside Agroforestry 9

port soil nutrients to leaves. Leaves contribute

organic matter to soil and release nutrients as

they decompose.

 Create and provide wildlife habitat –

Linear plantings of trees and/or shrubs in an

agricultural landscape increases the wildlife

habitat diversity, both through increased

amount of edge and/or as a result of the

increased diversity (vertical and horizontal) of

vegetative types. Increased vertical complexity has been correlated with higher bird numbers. These areas can also serve as protective

corridors for wildlife movement and provide

a food source.

 Reduce non-point source pollutants delivery off-site – Fertilizers, in excess of that

taken up by the crop, can be utilized by the

tree, shrub, and/or grass plantings whose root

density is typically greater than traditional

annual agronomic crops. This same benefit

can apply to pesticides and herbicides, which

infiltrate soil profiles and then move horizontally through the soil until reaching zones in

which plant roots act as filters.

Designing an alley cropping practice

 Determine the landowners objectives and

site conditions

 Consider the physical interactions between

the woody component and the crop

Each alley cropping practice can be

uniquely designed to reflect landowner needs

and site potential. However, there are physical interactions between the rows of woody

species and the companion crop that should

be understood and reflected in the alley cropping practice design. 

Physical growth traits of individual trees

and how these influence the crop, are based

on three factors:

 Light competition – A tree species should

be selected that best accommodates the light

needs of a selected crop. Some tree species

have small leaves and feathery foliage casting a light shade and lend themselves well to

alley cropping. Additionally, tree spacing

and row orientation, an understanding of

crown and foliage characteristics and timely

thinning are all considerations for managing

light intensity.

 Root competition – Competition for water

and nutrients between the tree and the intercropped species not only affects the yields of

the companion crop but also the growth of the

trees. Tree species have different root zones

and site requirements.

 Allelopathy – Traditionally, literature has

used the term allelopathy (Greek: allelon, on

another; pathos,suffering) to denote the negative biochemical influence exerted by one

plant on the growth of nearby plants. The

current trend is to accept a broader definition

that includes both the positive and negative

influence that a plant has on the growth of

nearby plants. This includes interactions

induced by the release of organic and other

chemicals, such as nitrogen, acids, and/or

growth inhibitors.

Companion crops are planted in the

alleys between the tree rows. The choice of

companion crops will vary depending on the

types of trees selected. There are three major

groups of crops that can be grown in an alley

cropping practice. Initially, the growing environment in the alley will be favorable to row

crops requiring full sun, but as the trees grow

they produce more shade leading the producer to either thin and prune the trees or switch

to a more shade tolerant crop.

Typical companion crops include:

 Row crops – Typical row crops, such as

corn, soybeans, or wheat, can be used for several years. Depending upon the selected tree

species and the row spacing, shade can

become a problem within three or four years

(fast-growing species such as poplar) or in a

decade or more with slower growing species

(oak, walnut, etc.).

 Forages – In an alley cropping practice,

forage crops such as fescue, orchard grass, or

alfalfa, are grown for hay production between

rows of planted trees, but are not grazed. This

distinguishes the alley cropping practice from

a silvopasture practice.

 Specialty – More often associated with

the forest farming practice, specialty crops

also have potential for integration into alley

cropping systems. Plants that can be marketed for their medicinal, ornamental, or food

values (including ginseng, St. John’s Wort,

goldenseal, wildflowers for seed, pumpkin,

small fruit trees, etc.) also provide unique

opportunities in alley cropping. Species that

are light demanding can be established in

the alleyways while those requiring some

shade can be planted within the tree rows as

shade develops.

Arrangement of tree rows and 

number of rows

As mentioned earlier, landowner objectives

will determine the products to be harvested

from the alley cropping practice. These objectives also determine the arrangement of trees

and crops and the set of management practices needed to obtain those products. Alley

cropping practices are highly diverse and

range from simple to complex. Plantings can

consist of a single or multiple tree species.

Similarly, single or multiple tree rows may be

used. While past practices have emphasized

the establishment of monocultures, today’s

emphasis on optimizing biodiversity and creating more sustainable systems requires different designs that incorporate mixed species

plantings. There are several key factors to

consider when planning and establishing the

practice on a given site:

 Single or mixed species, Single tree row

or multiple rows, Tree arrangement within

the row – Each of these considerations can

affect the following: biodiversity, wildlife

habitat, economics, plant competition, plantsee DESIGN (2) on page 11

Each alley cropping practice can be uniquely designed to reflect landowner needs and site

potential.
10 Inside Agroforestry | Fall 2001 / Winter 2002

Opportunities

continued from page 3

Whether in a small backyard or a larger farm or forest, trees

are vital to the web of life. Protecting and planting trees can

restore wildlife habitat, heal degraded land, conserve soil, protect watersheds, diversify farm or garden products, beautify

landscapes, and enhance the economic and ecological viability

of land use systems. Careful planning and sound information is

needed to reach these goals. 

The Overstory Book distills essential information about working with trees into 72 short, easy-to-read, single-subject chapters. Each chapter shares key concepts and useful information,

so readers can get back to effectively planting and protecting

more trees, gardens, and forests.

Book $39.95 plus shipping • CD $16.95 plus shipping

To order visit www.agroforestry.net or send check or money

order to Permanent Agriculture Resources, PO Box 428,

Holualoa, HI 96725 USA

The Overstory Book

Cultivating Connections with Trees

—A concise source of

pertinent information, 

a resource packed

with practical advice

and innovations.

Adam J. Tomasek,

World Wildlife Fund,

Washington, DC

for optimal production and conservation benefits. Through the application of agroforestry’s alley cropping principles, large acreages of

agricultural lands could gradually be removed from pure agricultural

crops and placed into various combinations of trees and crops without financial loss to the landowner and with much gain for society.

However, if alley cropping is to be broadly adopted and its

principles applied in North America, both need and opportunity

must be clearly demonstrated. Landowners, in general, and farmers

in particular must be convinced that if they practice alley cropping,

the accrued benefits, including profits earned, will justify their

actions. 

Alley cropping presents an opportunity for the family farm. It

capitalizes on the interactions created when trees and crops are

grown together and bridges the gap between production agriculture

and natural resource management while providing environmental

protection. Among the benefits resulting from the interactions created are increased crop production, alternative crops and diversified

rural economies, improved water quality, filtering and biodegrading

of excess nutrients and pesticides, reduced flooding, microclimate

moderation, diversified habitats for wildlife and people, and the

restoration of degraded ecosystems.

The face of rural America has changed from a constellation of

small family farms banding together to meet the food needs of a

hungry nation to one dominated by large corporate farms producing

surpluses that help feed hungry millions abroad. Our largest 600,000

farms account for more than ninety percent of US farm output. The

remaining 1.5 million farms produce only six percent of our food

needs. Found within that 1.5 million farms are millions of acres of

“under-used” land ideally suited for the application of agroforestry. 

In transitioning to alley cropping, owners of small family farms

could improve their finances and in the process retain a way of life

that has been handed down from one generation to the next. Longterm, they could expect strong markets for their wood products and

through careful planning could select companion crops for their

trees that could be marketed locally, regionally, and nationally.

Success of such an endeavor is obviously tied to maintaining a cash

flow while waiting for the trees to produce fruit (pecans, walnuts,

chestnuts), specialty products (pine straw, floral green products,

chemicals) or wood. This is achieved by carefully selecting crops

for which known markets exist and diversifying so that several markets can be explored simultaneously. Should a market dry up due to

competition, either new markets must be found or new crops established for which markets exist.

Rural America is in need of revitalization. While alley cropping’s potential varies by region due to diverse landscapes, values

and regional/local markets and economies, the need for adoption

and the opportunities afforded the adopter are without question.

Adoption within the US is currently on the upswing thanks to

greater landowner awareness. This heightened awareness is attributed to a dramatic increase in the number of professionals actively

researching and teaching agroforestry principles, better national and

regional organizations of agroforestry enthusiasts, and greater

involvement of these enthusiasts and their organizations in securing

state and national policies to support agroforestry.

It can provide multiple and long-term benefits to the user and

society and can help meet the ecological, socioeconomic and cultural needs of land management, provide raw wood products to

off-set the loss from public lands, and help preserve a way of

life that is critical to the revitalization of rural America.

From Northeast Agroforestry Carbon Conference

October 2-4, 2001 Binghampton, New York

Proceedings Now Available!

Please send a check in the amount of $25.00 payable to:

CNY RC&D, 99 North Broad Street, Norwich, NY 13815

Postage is included with this price. It weighs approximately

2.5 lbs and over 100 pages! Includes: Handouts, PowerPoint

presentations, etc.
Specialty Forest Products

Series of Color Brochures

Marketing Special Forest Products • Edible Woody Landscapes for People and

Wildlife • Productive Conservation: Growing Specialty Forest Products in

Agroforestry Plantings • Hybrid Hazelnuts: An Agroforestry Opportunity

These full-color, four-page publications provide invaluable information

for the entrepreneur interested in researching and beginning to produce special forest products. To preview any of these publications visit

NAC’s website, www.unl.edu/nac/pubs.html. Or, to request a copy email Nancy Hammond, nhammond@fs.fed.us.

Fall 2001 / Winter 2002 | Inside Agroforestry 11

Erosion

continued from page 5

and the inside row(s) a hardwood. The

conifers were placed in the outside rows to be

used as trainer trees to reduce lower branching on the high-value hardwoods, and also to

absorb the damage that machinery in the field

could cause on the hardwood crop trees. The

rows of trees were spaced about nine to 10

feet apart and the trees in the row were six

feet apart. Herbicide was applied in a band

along the tree rows to reduce weed and grass

competition during establishment. Vegetation

between the rows was periodically mowed.

An initial measurement of sedimentation in

the tree/grass strips at one site showed that

sediment was effectively trapped in the strip.

A third demonstration is being established at

Arbor Day Farm near Nebraska City,

Nebraska using a similar design but incorporating additional species that can be used for

decorative florals, nuts and fruits.

Although this type of system can provide

improved soil and water quality, is it economical? Incorporating trees into this type of soil

conservation system decreases the overall risk

in the farming operation by integrating a variety of crops that can respond to diverse markets. The agricultural crops provide annual

cash flow while the tree crops are increasing

in value over the long term. Depending on the

site characteristics, using fine hardwoods like

walnut, oak, ash, and pecan can potentially

produce high value lumber or veneer logs.

Incorporating improved tree and shrub

species that produce nuts, fruit or decorative

floral products can result in additional intermediate products and income. To determine

the economic feasibility of this approach and

the conditions needed to make it a competitive alternative, Dave Countryman and John

Murrow of Iowa State University conducted an economic analysis based on one of the Iowa

demonstrations. They used a row cropping

sequence of corn and soybeans with conventional tillage as a base and then added different conservation practices, including contour

strip cropping, contour tree buffer strips, and

terraces. A scenario incorporating income

from the Conservation Reserve Program

(CRP) was also included. The contour tree

buffer analysis included four tree species:

black walnut, red oak, white oak, and ash.

Sensitivity analyses were also carried out on

land values, real interest rates, and the projected costs and revenues associated with the

different scenarios.

Results from this study indicate that contour tree buffers provide an economically feasible alternative for agricultural lands that

have soil erosion, a low land value and low

crop yield. On higher value land wih greater

productivity the wide tree/grass strips were

not economically feasible. However, if the

value of other landowner objectives is considered, the economic feasibility will

improve. Contour tree buffers rely on the row

crop cash flow initially, but unlike some of

the other conservation practices, the contour

tree buffer provides future revenue. This

study focused on the economics of contour

tree buffers, but they also provide several

non-market values that are difficult to quantify. These non-market values may include

reduced soil erosion, improved water quality,

added landscape diversity, and enhanced

wildlife habitat. Landowners who value these

items and want to develop a long-term investment, should consider the contour tree buffer

alternative.

Adapted from: Economic Analysis of

Contour Tree Buffer Strips Using Present

Net Value. By D.W. Countryman and J.C.

Murrow in Journal of Soil and

Water Conservation, Second

Quarter, 2000. Volume 55,

Number 2. Pp. 152-160.

insect relationships, the environment, tree

form, and erosion.

 Width of alleys – Tree rows are typically

established in a straight line, or along a contour, with an alley between them. Whether

single or multiple tree rows are established,

the overall success of any alley cropping program often is linked directly to the spacing

between the rows of trees. Allowing for adequate space for the annual crop is a must if

the system is to be economically productive.

 Equipment size – It is important to consider the size of all farm equipment that will be

operating in the alleys. The alley should be

wide enough to allow clear passage of the

widest piece of equipment. Another alternative is to allow clear passage of multiple

widths of equipment (Example: 13-foot wide

disk and 60-foot alleyway allowing four passes of the disk [52 feet] plus a buffer to ensure

that no damage is done to the trees). Be sure

to plan for space of the tree crown area. This

is particularly important in nut production

when early crown development is desirable. 

 Changes through time – Over time, shade

in the alleyways will increase due to the

developing crowns. Row crops can be grown

until shading reduces the productivity of the

site for those crops. At this time, the companion crops must be changed or trees must be

thinned to reduce competition.

Alley cropping offers another land stewardship alternative to convert degraded lands,

protect sensitive lands, and diversify farm

production systems.

Adapted from: “Designing an Alley

Cropping Agroforestry Practice” By Gene

Garrett and Dusty Walter in Agroforestry

Training Manual: Applied Land Use

Practices UMCA-2-2000.

Design (2)

continued from page 9
National Agroforestry Center

East Campus-UNL

Lincoln, Nebraska 68583-0822

PRSRT STD

POSTAGE & FEES PAID

USDA — FS

PERMIT NO G-40

April 1-3, 2002

13th Central Hardwood Forest 

Conference, Urbana-Champaign, IL, 

Contact: Scott C. Miller, Phone: 

217-333-2880; Fax: 217-333-9561; 

scmiller@uiuc.edu

April - June, 2002

Silvopasture Training Workshops for 

natural resource professionals in 

AL, FL, SC and potentially GA. 

Contact: Sid Brantly, Phone: 334-887-

4568; Sid.Brantly@al.usda.gov

July 13-17, 2002

Soil and Water Conservation Society 

2002 Annual Conference; Theme: 

"Setting the Pace for Conservation." 

Indianapolis, IN, Contact: Nikki 

McClain, 765-747-5531; 

www.hoosierchapterswcs.org/

activities/settingpace

October 5-9, 2002

Society of American Foresters 

National Convention. Theme: Forests 

at Work ; Benton Convention Center; 

Official Business

Penalty for Private Use, $300

Winston-Salem, NC www.safnet.org/

calendar/presentations

October 8-10, 2002

Changing Faces of Conservation and

Agriculture: The Future of Working

Lands, Soil and Water Conservation

Society; Moline, IL, Contacts: Chris

Murray, chrism@agribiz.org; Lynn

Betts, lynn.betts@ia.usda.gov;

http://www.iaswcs.org/west_north_central.htm

Agroforestry | Fall 2001 / Winter 2002 Inside

Upcoming Events

Inside Agroforestry is published quarterly by the USDA

National Agroforestry Center. 

Phone: 402-437-5178; Fax: 402-437-5712.

Greg Ruark, Center Director ext. 27

Michele Schoeneberger, 

FS Research Leader ext. 21

Rich Straight, FS Lead Agroforester ext. 24

Bruce Wight, NRCS Lead Agroforester ext. 36

Kimberly Stuhr, TT Specialist/IA Editor ext. 13

Ryan Dee, TT Assistant ext. 14

Mike Majeski, FS Agroforester

St. Paul, MN phone: 651-649-5240

Jim Robinson, NRCS Agroforester 

Fort Worth, TX phone: 817-509-3215

Gary Kuhn, NRCS Agroforester 

Spokane, WA phone: 509-358-7946

www.unl.edu/nac

The USDA National Agroforestry Center (NAC) is a partnership of the Forest Service, Research &

Development (Rocky Mountain Research Station) and State & Private Forestry and the Natural Resources

Conservation Service. The Center’s purpose is to accelerate the development and application of agroforestry

technologies to attain more economically, environmentally, and socially sustainable land-use systems. To

accomplish its mission, the Center interacts 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.

USDA policy prohibits discrimination because of race, color, national origin, sex, age, religion, or handicapping condition.

Any person who believes he or she has been discriminated against in any USDA-related activity should immediately contact the Secretary of Agriculture, Washington, DC 20250.

Opinions expressed in Inside Agroforestry are those of the author and do not necessarily represent the policy of the USDA

Forest Service and the USDA Natural Resources Conservation Service.

Mission