Summer 2004

Inside 

3 THIS SURE BEATS USING AN

ABACUS.

VISUAL SIMULATIONS: 5 THE ART OF GOOD PLANNING

ASSESS THIS.

Most would agree that having the righttools on hand can make just about any

job easier. Ever try to cut a tree down with a

sledgehammer? You’d probably find that an

ax would make that chore a whole lot easier.

Along with ease, the right tools can also

help save time and money. It’s well worth the

effort to keep abreast of new technology. For

example, today, a chain saw, or even a fellerbuncher, is probably the tool of choice when

cutting down a tree. 

In this issue of Inside Agroforestry, you’ll

find that numerous tools exist for you to use

when designing agroforestry plantings. It’s difficult to imagine what a tree planting might

look like in 20 years. But with CanVis, a new

visual simulation tool developed by NAC, you

can digitally alter photos to illustrate a proposed design alternative. And, if you have to

wait 20 years, you probably want to make sure

your windbreak will meet your expectations.

Using WBECON (WindBreak ECONomics)

computer program, you can calculate the economics of a crop field with windbreaks, all

while taking into account various factors, like

windbreak species and design, soil and climate, crop rotation, yields, and prices.

Here’s a chance to get some new

agroforestry tools for your tool bench!

If your only tool is a hammer,

you tend to see every problem as a nail.

Abraham Maslow

”

“
costs for installation and maintenance budgets and county soil rental rates for calculating program payments. Default values

from Nebraska are used to demonstrate the

tool. You can easily customize the tool for

your area by entering your NRCS state

average costs and local county soil rental

rates. Buffer$ can be downloaded from the

NAC's website www.unl.edu/nac/

conservation/ and requires Microsoft Excel

to run. A free CD with Buffer$ can

also be requested by contacting NAC

at (402) 437-5178.

1st World Congress of Agroforestry

NAC Director’s Corner

A commentary on the status of agroforestry by NAC Director, Dr. Greg Ruark

2 Inside Agroforestry |Summer 2004

Participants from 82 countries gathered in Orlando, Floridafrom June 27 to July 2, 2004 for the 1st World Congress of

Agroforestry. Over the past 25 years significant progress has

been made in building a scientific foundation for the design,

installation, and management of agroforestry systems. The

resultant gains in crop production and diversification, economic performance, and environmental benefits serve to illustrate the value of agroforestry research and technology development efforts and argue for the need to expand our gains to

better meet societal demands. 

The Congress produced two books that document the current state-of-knowledge and practice of agroforestry worldwide. These books have already been published and they provide valuable resource tools for those wishing to further

explore the potentials of agroforestry. The 1st World Congress of

Agroforestry Book of Abstracts (426 pages) contains summaries

of the talks and poster sessions and represents the collective

endeavor of hundreds of researchers, extensionists,

landowners, students, and others involved in agroforestry.

The second book is titled New Vista in Agroforestry: A

Compendium for the 1st World Congress of Agroforestry, 2004 (480

pages) and it offers a state-of-the-art synthesis of agroforestry

as it applies to a broad array of topics in both temperate and

tropical ecosystems.

More details on how to acquire these books can be

obtained on the conference website at 

http://conference.ifas.ufl.edu/wca.

Critics say, “Two thumbs up... Buffer$ pay!”

"Buffer$ allows me to quickly calculate an

economic return on buffers, saving me valuable time with landowners" says Don Ulrich,

a conservation professional with the Natural

Resources Conservation Service (NRCS). In

the previous issue of Inside Agroforestry, we

presented Buffer$, a spreadsheet-based application developed by the USDA National

Agroforestry Center (NAC) to assist

When people can estimate the costs of changing their

minds before they install a practice, we are more likely to see

conservation on-the-ground ten years after the installation.

Madalene Ransom, NRCS Economist

Gary Bentrup

Research Landscape Planner

Lincoln, Nebraska

landowners and planners in analyzing the

cost-benefits of conservation buffers. Buffer$

can calculate potential income from a buffer

using cost-share programs, growing agroforestry specialty products, and incorporating

other income opportunities. To aid in decision-making, the tool can compare potential

income generated between a buffer alternative and a cropping alternative. 

Although recently released, this tool is

already gaining popularity with conservation

professionals because it has an easy-to-use

interface. Buffer$ uses state average NRCS

“

”
see WINDBREAK ECONOMICS on page seven

Field windbreaks reduce wind speeds for a distance of20 to 30 times their own height (H) and increase

crop yields out to about 15H. Although they compete

with crops within their root zone (about 1H) and take

land out of production, at maturity, the overall production increases at the field level usually outweigh any localized decreases.

The computer program, WindBreak ECONomics

(WBECON), was created to calculate the economics of

field windbreaks over their lifespan. WBECON is a useful

tool for natural resource professionals and landowners. It

calculates the economics of windbreaks taking into

account various factors such as species and characteristics, design, soil and climate factors, crop rotation, windbreak costs, crop costs and crop prices. For each year of

the windbreak’s life, from the time of planting or from a

specified age, costs and benefits are calculated. Costs

include windbreak establishment, maintenance, and

removal, yield losses due to competition, and land taken

out of production. The benefits are crop yield increases

for each year and reduced input costs. Other economic

benefits, such as soil erosion control and crops from

windbreak trees, are not considered in the program.

The user enters the following information:

• Soil texture, moisture condition, and prevailing wind

• Crop rotation (for up to five years), production 

costs, crop prices, expected yield without shelter

• Field dimensions

• Windbreak species, placement, and number

After the user has entered all of the necessary information, the computer does the calculations.

The output summarizes inputs and assumptions used

in the calculations. The program calculates the annual

benefits of the windbreak at maturity in constant dollars.

Most importantly, the windbreak’s Net Present Value

Windbreak structure - height, density,

number of rows, species composition,

length, orientation, and continuity - 

determine how effective a 

windbreak will be.
Agroforestry opportunities are being identified

using geographic information systems (GIS), a collection of computer hardware and software used to analyze and display geographically referenced data.

Using readily-available data layers like soils, slope, and

land cover, suitable locations for agroforestry practices can be identified. 

In the Pacific Northwest, fast growing hybrid

poplar are being increasingly used by the pulpwood

industry. To assist landowners who are considering

diversifying their operations with poplar, optimal

growing sites need to be identified. Dave Hoover,

State GIS coordinator for Idaho NRCS, analyzed

regional soils data using GIS to find the most suitable

sites in the Pacific Northwest

for hybrid poplar.

At the Center for Subtropical

Agroforestry (CSTAF) located

at the University of Florida,

researchers have been developing an online GIS database to

help landowners and agroforestry practitioners select

plants for southern agroforestry systems. The

Southeastern Agroforestry Decision Support System

(SEADSS) allows users to select an area of interest

and view information on soils, land use, climate, and

other data. Based on these data, the tool provides a

list of agroforestry plants suitable for the site. Because

the GIS tool is linked to a plant database, a user can

quickly find out more information on the recommended plants, including management and propagation, products and services, and species photos. The

tool is currently being developed for counties in

Florida. Future plans include developing SEADSS

for Alabama and Georgia. More information can be

found at http://cstaf.ifas.ufl.edu/SEADSS.htm.

The most significant benefit of using GIS in agroforestry is the ability to combine different assessment

results to simultaneously address rural landowner and

community issues. Landowner goals, like minimizing

soil erosion and providing crop diversification, may

be accomplished by just focusing on site conditions,

4 Inside Agroforestry |Summer 2004

Gary Bentrup

Research Landscape Planner

Lincoln, Nebraska

however to solve community-driven goals like water

quality and wildlife habitat requires a larger scale perspective. GIS can provide a way to integrate these

different concerns by efficiently combining information from different scales.

At the USDA National Agroforestry Center

(NAC), multi-scale GIS-guided assessments are being

developed for water quality, wildlife habitat, soil protection, and agroforestry specialty products for the

western corn belt ecoregion of the U.S. The individual assessments are then combined to identify

where several objectives can be accomplished with

agroforestry practices. For instance, one of NAC's

assessments has identified perennial vegetation gaps

in riparian corridors that could be restored to facilitate wildlife species movement and provide surface

runoff filtration. Another assessment has identified

suitable locations

where decorative

woody florals, like

curly willow and

pussy willow, can be

grown. University of

Nebraska researchers

have shown potential

annual net returns ranging from $400 to $3500 per

1000 feet at four- to six-foot plant spacing. By combining these assessments results, areas are identified

where riparian buffers can be located to improve

habitat connectivity and protect water quality while

offering landowners the option to grow a product for

profit. More information can be found at:

www.unl.edu/nac/conservation/.

Depending on the scale of analysis, GIS-guided

assessments can support conservation policy and program development, prioritize projects, develop technology transfer programs, guide additional research,

and influence site-scale planning and design. Many

states have internet-accessible GIS data clearinghouses providing free spatial information, and skilled

GIS technicians can now be found in many state and

county-level resource management agencies which

may be able to provide assistance. Promoting acceptance, support, and adoption of agroforestry

will be easier with GIS mapping the way.

GIS maps 

help illustrate

where 

plantings can

be installed 

to enhance

wildlife

habitat, 

protect water

quality, and

increase 

economic

diversity.

Mapping

opportunities 

for agroforestry
agricultural features, people, and urban

park elements that can be quickly added to

the base image. This saves users' valuable

time by not having to create plant and

other images from scratch. Some of the

other tools available in CanVis include

adding shadows and text, cloning textures,

and adding hardscape elements like pathways and walls. This program will be available this fall. For more information, check

NAC's website www.unl.edu/nac/

conservation/.

Summer 2004 |Inside Agroforestry 5

"What will it look like?" Natural resource

professionals often hear those words from

landowners who have difficulty picturing a

proposed agroforestry tree planting or conservation plan. Planting plans and engineering

drawings, while necessary documents, often

mean very little to the general public.

Landowners lament that if they could only

see a picture of the final project. 

Now resource professionals have a visual

simulation tool to illustrate their design ideas.

Visual simulations are images that have been

digitally altered to illustrate a proposed design

alternative. Digital photos of the landowner's

property can be acquired by scanning photographs or taking pictures with a digital

camera. Using image-editing software, the

proposed design can be "created" by adding

images of trees, shrubs, grass, and other materials onto the base image of the landowner's

Visual simulations can be created using

software programs like JASC PaintShop

Pro and Adobe Photoshop Elements. While

these programs are quite powerful for creating simulations, they can take some time

to learn how to use them. In response,

NAC has developed a software program

that allows resource professionals to create

realistic simulations with minimal computer skills. One of the main benefits of

CanVis is its collection of object libraries

that contain images of plants materials,

Gary Bentrup

Research Landscape Planner

Lincoln, Nebraska

property. In a relatively short time, windbreaks, riparian buffers and other conservation practices can be depicted in rural and

urban environments.

In addition to communicating ideas and

design alternatives, visual simulations can be

used to engage the public in the design and

decision-making process. For example, a

Wisconsin community was opposing a proposed flood control dike because they had

difficulty visualizing how it would impact a

local park. Visual simulations were used at

public meetings and in the newspaper to

better explain the proposal. Once the public

saw the proposal, there was overwhelming

support for the project.

Visual simulations can be used as a marketing tool for new programs and as a

training aid to help new employees visualize

new concepts.

To facilitate the use of visual simulations in

agroforestry and conservation planning, the

USDA National Agroforestry Center (NAC)

is creating a manual to show users how to

create realistic and accurate simulations. The

manual will provide detailed information on

acquiring images and how to edit the images

using a variety of available software programs.

The core of the manual will focus on how to

size and locate plant materials and other

objects in the images using perspective and

scaling principles. Using the manual, resource

professionals will be able to gain the skill and

confidence that the simulations they create

are accurate depictions of the proposed

design alternative. See NAC’s website,

www.unl.edu/nac/conservation/, for

the manual availability this fall.

Visual simulations aid in

resource planning

Visual simulations were used at public meetings and in the

newspapers to better explain the proposal. Once the public saw

the proposal, there was overwhelming support for the project.

Pixel this:

Original photo Contour buffer strips, riparian

forest buffers, and windbreaks

are all simulated.
According to data from the USDA Farm Services Agency

(FSA), over 1.5 million acres of riparian forest buffers and

filter strips have been installed on American farmlands through the

CRP program. Most of these buffers have been installed according

to general program guidelines and not necessarily custom designed

to the site specific soils, slope, and vegetation cover or even modified with respect to other upland conservation practices on the

same fields. Consequently, we as resource professionals need a way

to evaluate riparian buffer function in order to know that our conservation program dollars are being used effectively.

With these issues in mind, Mike Dosskey, of the National

Agroforestry Center and Matt Helmers, Dean Eisenhauer, Tom

Franti, and Kyle Hoagland, all of the University of Nebraska, set

about to

develop a

field-based

approach

for

assessing

the sediment trapping efficiency of

riparian

buffers. It

has been

long recognized that

the concentration of runoff flows reduces the effectiveness of

riparian buffers because only a portion of the buffer will interact

with the field runoff. This group of researchers devised a visual

buffer evaluation system that takes into account the effects of

concentrated flows, without requiring lots of expensive monitoring equipment and time. 

It’s sedimentary: EBA/FRA=efficiency

They found that the relationship of the “effective buffer area”

(EBA), that area of the buffer that actually receives runoff, to the

“field runoff area” (FRA), that area of the field that contributes

runoff through the buffer, is a very good indicator of the buffer’s

sediment trapping efficiency (see Figure One). 

The field runoff area is delineated by walking the field margins

adjacent to the buffer examining the topography, microrelief, and

patterns of erosion and deposition of soil and crop debris. 

The effective

buffer area estimation is more

subjective and

requires careful

interpretation

of the runoff

flow path from

the field area

and into and

across the

buffer to the stream. One of the most critical areas to examine is

the field margin where sediment deposits and tillage berms often

direct runoff to flow and concentrate along the edge of the buffer

for relatively long distances before finally entering the buffer (see

Figure Two).

The visual indicators of the runoff flow direction are far easier

to find in the spring before buffer vegetation gets to tall and the

crop closes canopy over the field. This visual approach to

assessing sediment trapping of buffers is relevant for 10-year rain

events or larger. Although this appears to ignore more frequent

rain events, the researchers believe that the 10-year event is a good

indicator of runoff patterns. 

More details can be found in the article, Assessment of concentrated flow through riparian buffers, Journal of Soil and Water

Conservation. (2002) 57: 336-343.

Figure Two: Field runoff schematic.

Figure One: Sediment trapping graph.

Moving from generality to specificity in buffer assessments
Summer 2004 |Inside Agroforestry 7

Windbreak Economics

continued from page three

I

n agroforestry, it is often important to manage the tree over story

canopy density in order to produce the

desired crops in the under story. This

is especially true for the practices of

silvopasture, forest farming, and, in

some instances, alley cropping. 

Canopy has often been calculated

using ocular estimates which have

been shown to be neither accurate nor

reliable by two different people. The

spherical densiometer is a simple,

inexpensive tool that will often meet

the needs for collecting canopy estimates. It is essentially a convex, circular mirror etched with a grid that

divides the mirror into 24 squares.

To use a densitometer:

•Hold instrument level, with the 

mirror pointing up, 12 to 18 

inches in front of body and at 

elbow height.

•Assume four equal-spaced dots 

in each square on the grid and 

systematically tally the dots 

covered by canopy material.

•Total dot count equals the 

percent canopy closure. 

•Make four readings per sample 

point-facing North, South, 

East and West.

This will provide a reliable

estimate for managing canopy

density in agroforestry systems.

Best Management Practices or BMPs havebecome a part of our conservation language as a result of the 1987 Clean Water Act

(CWA). The CWA has identified BMPs as the

primary means to address non-point source

water pollution. The Environmental

Protection Agency (EPA), is required to show

evidence of enforcement and has long sought

a standard BMP monitoring protocol to provide measurable data that are reliable and

comparable among states. As a result, many

states, universities, federal agencies, companies, and organizations

have developed BMPs

to guide their land use

management activities. 

The forest management community is no

different. In fact, the

term BMP was defined

to refer to precautionary activities designed to protect water

resources during timber harvests. It is in the

best interest of those involved in timber harvesting activities to effectively use BMPs

because then they are exempt from permitting

requirements under the CWA. 

However, individual state monitoring has

been sporadic, qualitative, and only marginally acceptable as a measure of effectiveness.

State Forestry agencies have sighted manpower, time, cost, reluctance to change their

individual BMP specifications, and monitoring team makeup as barriers to acquiring a

common protocol. 

The Northeastern Area Association of

State Foresters, Water Resources Committee

Is your BMP working?

Agroforestry tools:

The spherical densiometer

(NAASF), using a grant from the U.S. Forest

Service has initiated a project to create a

regional BMP monitoring protocol. The protocol focuses on water crossings and riparian

areas as having greater potential to adversely

impact water resources. Evaluating BMP principles, incorporating a quality control system,

and recording impacts on GPS units will

overcome state agency barriers and permit

evaluation by watershed, political or other

boundaries. Quantitative data will permit

computer modeling and provide a meaningful

foundation for risk and

impact analysis and a

defensible measure of

the impact of forest

management activities

on water resources.

Since Version 1,

the monitoring protocol has been through

two seasons of field testing in 10 northeastern

states and the equipment cost was reduced by

a factor of ten when the protocol was adapted

for use in PDAs Pocket PCs and Trimble

units using Pendragon and Windows software. Several western states are also looking at

this protocol for evaluating timber harvesting

activities in their regions.

Although this monitoring protocol has

been developed to evaluate timber harvest

activity BMPs, the protocol may become the

foundation for evaluating other land use

BMPs.

Adapted from A Protocol for Monitoring

Best Management Practices, USDA Forest

Service Northeastern Area bulletin.

(NPV) is calculated. NPV is the net benefit

over the windbreak’s life-span in which the

benefit calculated each year in constant dollars is discounted at an annual discount rate

to account for real interest rates. For

example, at a five percent discount rate,

$100 earned at the beginning of the first

year has a present value of $100 but $100

earned one year in the future has a present

value of only $95. The NPV is important

because it permits a realistic comparison of

windbreaks which have different life-spans

and growth rates.

It is easy to change windbreak design,

crop rotation, and other factors and recalculate the economic benefit. This allows the

user to try out different scenarios and assess

the sensitivity of NPV to changes in inputs. 

For more information or to get a copy of

WBECON, contact Jim Brandle at

jbrandle1@unl.edu or, in Canada,

John Kort at kortj@agr.gc.ca.

The protocol focuses on 

water crossings and riparian

areas as having greater 

potential to adversely 

impact water resources.

Protocol helps to protect our nation’s water resources
National Agroforestry Center

East Campus-UNL

Lincoln, Nebraska 68583-0822

PRSRT STD

POSTAGE & FEES PAID

USDA — FS

PERMIT NO G-40

September 18-19, 2004

“Goods from the Woods Marketplace.” 

Grand Rapids, Minnesota. 

http://specialforestproducts.com/woods/

marketplace.php

September 18-19, 2004

Northeast Small Farm & Rural Living 

Expo. New Paltz, New York. 

www.smallfarmexpo.com

October 2, 2004

“Wild Fruit and Nut Jam.” Nebraska 

City, Nebraska. Contact: Scott Josiah, 

sjosiah@unlnotes.unl.edu

October 2-6, 2004

“One Forest Under Two Flags.” Society of

American Foresters / Canadian Institute 

of Forestry. Edmonton, Alberta, Canada. 

www.safnet.org/convention

Official Business

Penalty for Private Use, $300

Address Correction Requested

Summer 2004 | Agroforestry Inside

Upcoming Events

Inside Agroforestry is published quarterly by the 

USDA National Agroforestry Center. 

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

Greg Ruark, NAC Director ext. 27

Michele Schoeneberger, FS Research Lead 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.

NAC’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, NAC 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 Natural Resources 

Conservation Service Rocky Mountain Research Station

October 10, 2004

Third Annual Catskill Mountain Ginseng 

& Medicinal Herb Festival. Catskill, New 

York. Contact: (515) 965-2883, 

hoca@mhonline.net.

October 16, 2004

Missouri Chestnut Roast. New Franklin, 

Missouri. thtp://agebb.missouri.edu/umca/

events/chestnut.asp