Spring 1996
U.S. Department of Energy
Bioenergy Feedstock Development Program at
Oak Ridge National Laboratory
Energy Crops Forum was published periodically by the Bioenergy
Feedstock Development Program, Environmental Sciences Division, Oak Ridge
National Laboratory, managed by UT-Battelle, LLC., for the U.S. Department of
Energy under Contract No. DE-AC05-00OR22725.
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Table of Contents
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Virginia Tolbert, Biofuels Feedstock Development Program
The Environmental Research task of the Biofuels Feedstock Development Program
(BFDP) supports research to understand environmental changes that may occur
from growing biomass crops. This includes changes in soil erosion, soil
structure, chemical movement through soil, water quality, sequestration of
carbon, and wildlife habitat use from planting biomass crops (hardwood trees
and perennial grasses) on fallow or active agricultural lands. BFDP research on
the interactions between biomass crops and wildlife is designed to develop
useful, informative guidelines that will assist biomass producers in achieving
both economic and wildlife values from their crops.
Specific research questions about wildlife habitat and energy crop production
currently include the following :
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How do energy crop plantings compare with other land uses (e.g., row crops, hay
fields, native grasslands, forests) as habitat for selected wildlife species?
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How do different energy crop characteristics (e.g., acreage, age, species,
adjacent land uses) affect wildlife use of the energy crop?
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How do energy crops with particular characteristics affect wildlife in adjacent
natural or managed habitats?
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How can growers manage biomass crops to optimize energy and economic values in
different regions of the country while simultaneously benefiting native
wildlife?
Since 1992, environmental research funded by BFDP has addressed whether the
diversity of bird and small mammal species in row crops and on Conservation
Reserve Program lands (erosive agricultural lands temporarily retired through a
government program) changes when these lands are planted with fast-growing
trees for energy and fiber. This research has also looked at how bird and small
mammal communities respond when agricultural land is used for energy crop
acreage and vegetation structure.
Birds and small mammals are sensitive to changes in habitat at different
scales—birds are broad ranging whereas small mammals are confined to smaller
areas by their lack of mobility—and use different components of the habitat.
Consequently, these are complementary species groups to use in assessing native
wildlife response to changes in land use. BFDP hopes to complement ongoing
wildlife research in the north-central and southeast United States in the near
future by including studies in other regions. We hope to monitor plantings of
additional hardwood tree species, to assess tree crops over their full growth
cycles from planting to harvest, to evaluate large acreage plantings, and also
to explore how large mammals and other wildlife groups use energy crops as
habitat.
To date, studies of biomass plantings conducted in the north-central United
States have shown that hardwood tree crops support increased diversity of birds
in comparison with row crops. However, the habitat value of these tree
plantings for birds was less than that of natural forest. In the Pacific
Northwest, breeding birds used the more mature poplar plantings but fall
migrant birds did not. Studies in Iowa showed that switchgrass provided an
enhanced habitat over row crops for grassland birds. Bird communities were
found to be more highly influenced by the surrounding landscape than by the
structure of the switchgrass plantings. Bird communities also differed between
the studied plantings and the various habitat types surrounding the switchgrass
(wetland, forest, row crop). Bird species found in adjacent surveyed woodlands
were not found in the younger, more open tree plantings.
Studies of small mammals found differences in habitat use in tree plantings,
nearby natural wooded areas, row crops, and grasslands. Before canopy closure,
small mammal species using the plantings were similar to those using
grasslands. The tree plantings provided improved habitat value over row crops
for small mammals. More grass cover and increased vegetation diversity within
the tree plantings, tree deaths and differences in planting and management
techniques, increased small mammal density and diversity in the plantings. The
results of these studies are specific to hybrid poplars planted in the
northwest and north-central United States and to switchgrass plantings in the
north-central United States.
BFDP is continuing to define and promote cooperative research in other areas and
on plantings of different species. These studies will be conducted on larger
and older plantings (closed canopy) than the research conducted thus far. They
will more accurately address total effects and define maximum potential
benefits for wildlife diversity with energy crop development.
New research data will complement existing information and help direct future
plantings of biomass crops to enhance habitat for wildlife while meeting
production and grower needs.
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Richard Schultz, Iowa State University
Bountiful production of corn and soybeans can cause pollution of streams and
groundwater. Along many miles of Iowa streams, row crops are grown down to the
stream edge or cattle are grazed in narrow bands of land that include the
stream and its flood plain. Before European settlement, Iowa had many more
miles of streams that carried cleaner water than today. Floodplain forests,
prairies, and wetlands along the streams regulated water flow and quality and
provided wildlife habitat. As these plant communities were cleared and laid
fallow for part of each year, and as many fields were tiled and stream channels
were straightened, large amounts of soil and chemicals were carried to the
streams. Streams carried more water after rains, which collapsed streambanks
and caused them to erode deeper into the landscape.
Concerns about water quality and an interest in reestablishing forests,
prairies, and wetlands in Iowa and the Midwest led the Iowa State Agroforestry
Research Team (IStART) and the Agroecology Issue Team of the Leopold Center for
Sustainable Agriculture to develop a streamside management system. The
multispecies system uses trees, shrubs, and prairie plants as a buffer strip
along a stream. The basic model consists of four rows of trees planted along
the stream edge, followed by two rows of shrubs and then a strip of prairie
plants planted along the edge of the crop field. This plant community provides
a frictional surface that slows surface erosion and causes water and chemicals
to soak into a "living filter" made up of soil, plant roots, microbes, and soil
animals. Water moving through this filter is cleaned and slowly released to the
stream channel. Many variations of this model, with widths from 50 to 100 feet,
can be planted depending on the landscape features and landowner objectives.
The rich soil along the stream edge can support many species of trees, shrubs,
and prairie plants. The key is to get this plant community rapidly established.
To accomplish this, fast-growing trees such as willow, poplar hybrids, and
silver maple are usually planted in the two rows closest to the stream. The
other rows may consist of fine hardwoods such as black walnut, oaks, and ash.
Many species of shrubs can be planted to diversify the habitat for wildlife.
This system has been shown to reduce chemicals and surface erosion by as much
as 80%. Four times more bird species use this system than use the straightened
streams where corn and beans are grown to the edge. If planted as a short-
rotation woody crop or biomass energy system, all of the woody rows can be
planted with tree species such as willow, poplar hybrids, or silver maple. The
switchgrass strip provides an herbaceous energy crop.
Another important component of this system is the use of willows and certain
shrubs to stabilize the streambanks themselves. As much as 50–60% of the
sediment carried in streams can come from the collapse of streambanks. Woody
tree and shrub species that are able to produce roots from stem segments are
pounded or pushed into the streambank, where they hold the soil in place once
they have rooted and grown tops. The amount of work needed to assure success of
this procedure depends on the height and shape of the streambank. Where
streambanks are less than four feet high, it is possible to simply push or
pound two rows of willow posts, large cuttings up to 4–5 feet long, along the
bottom of the bank. Higher up the bank, smaller cuttings are pushed into the
bank. If the banks are 4–10 feet in height, the toe of the bank must be
specially stabilized with rock or red cedars to reduce the chance of
undercutting and collapse of the streambank. Willow posts and cuttings are
planted between the cedars or rock. Where vertical streambanks are 10 feet or
more in height, equipment is used to produce a gentler slope (2:1). Grass may
be seeded and a fiber mat staked down before the willow and shrubs are planted.
In this case, stabilizing the toe of the bank with cedars or rock is even more
important. These streambank bioengineering techniques can effectively stop
erosion along critical streambanks and protect such structures as bridges,
buildings, and fences that may be threatened by channel erosion.
The last component of the streamside management system is a small constructed
wetland built within the buffer strip where a field tiledrains into the stream.
A shallow depression, no deeper than 2 feet at the center, is excavated and
planted with cattails, bulrushes, and other wetland plants. Such wetlands, when
properly designed and maintained, can remove most of the nitrate contained in
the tile water. Microbes attached to sediments and decaying plant material use
the nitrate molecule in place of oxygen to provide them air to "breathe" while
releasing harmless nitrogen gas into the atmosphere.
The streamside management system, in concert with upland conservation practices
such as minimum tillage, grass waterways, and terracing, can effectively reduce
pollution produced by agriculture. At the same time it can provide diversified
products for the landowner and a diverse habitat for improved wildlife and
aesthetics. Native trees and shrubs together with prairie plants can help
improve water quality and protect the long-term sustainability of Iowa and
Midwestern farmland.
For additional information, contact the author at Iowa State University, College
of Agriculture, 251 Bessey Hall, Ames, Iowa 50011-1021, 515-294-7602.
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Dan Robison, SUNY
The wood biomass–bioenergy program at the State University of New York College
of Environmental Science and Forestry (SUNY ESF) in Syracuse has focused recent
work on developing a wood biomass production system for the northeast based on
an operational system in Sweden. This agri-forest system is based on a
double-row planting of approximately 6,200 willow trees per acre and is
harvested on a 3-year coppice cycle after being cutback the first year to
promote multiple sprouting and full site occupancy.
Mechanized planting and harvesting equipment has been commercialized in Europe.
Equipment configurations include 2- and 4- row planters which can plant 10 in.
precut cuttings or 1–2 yd long whips, cutting each off at 10 in. after
insertion. Mechanized direct- chip harvesters are modified from corn and sugar
cane harvesting machines, which cut and chip in a single operation, or from
whole- stem harvesters, much like old-fashioned reapers, which cut and stack
willow or poplar stems for storage and drying in the field, and for later
movement by grapple for transport and stationary chipping. These systems are
operational in Sweden and other areas of Europe and are under development by
SUNY ESF and the University of Toronto (UT) for use in North America.
Research and development at SUNY ESF has concentrated on willow clones but has
also included the introduction of select hybrid poplar clones into the system,
cooperation with the UT on clonal improvement and the testing of more than 300
willow clones, and experimental yields as high as 10.6 oven-dry tons per acre
per year. Ongoing clonal improvement through the SUNY ESF–UT efforts and
through work in Sweden is expected to increase yields by as much as 20-30%.
Other research topics include pest management, carbon sequestration, nutrient
cycling, organic soil amendments, clonal deployment patterns, and economics.
Scale-up activities have included a variety of clone-site and demonstration
trials including 12 acres established in 1995 and 17 acres planned for 1996. In
addition to continued support from the Biofuels Feedstock Development Program
for research and development efforts, a U.S. Department of Agriculture grant
will facilitate the establishment of a 60–100 acre research and demonstration
farm in 1996.
In public meetings, farmers and landowners have indicated a strong interest in
bioenergy crop production. SUNY ESF along with its sponsors/cooperators has
built a broad partnership across the northeast with industry, and
nongovernmental and government agencies. The principle partners include New
York State Energy Research and Development Authority, Niagara Mohawk Power
Corporation, New York State Electric and Gas Corp., South-Central New York
Resource Conservation and Development District, Burlington Electric Department,
Empire State Electric Energy Research Corp., New York Gas Group, and UT. A
feasibility study, recently completed by this partnership for the National
Renewable Energy Laboratory and the Electric Power Research Institute,
indicated a bottom line price of $1.96 per MBtu biomass by 2001.
For additional information, contact the author at State University of New York,
College of Environmental Science and Forestry, One Forestry Drive, Syracuse,
New York 13210-2778, 315-470-6774.
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Recent polls have indicated that renewable energy is publicly more popular than
ever before. The Biomass Energy Alliance, a non-profit organization, was
created to make policy makers and the public aware of the many benefits of
biomass use, which is second only to hydroelectric among renewable energy
technologies, and to accelerate the development of a major new American
industry. The Alliance seeks to bring together individuals and groups who
support these objectives -- for reasons as varied as the benefits themselves. A
united coalition of researchers, farmers, environmentalists, and industry is
essential to maintaining support for biomass energy.
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BFDP Subcontractors' Workshop, September 9-13, 1996, Ames,
Iowa. Hosted by Iowa State University. Details are being worked out as this
issue of Energy Crops Forum goes to press. To receive information as
it becomes available, contact Wilma McNabb, Biofuels Feedstock Development
Program, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN
37831-6422, E-mail: wmx@ornl.gov,
865-574-8029, 865-576-8143 (fax).
BIOENERGY '96 — The Seventh National Bioenergy Conference and ASAE Liquid
Fuels and Industrial Products from Renewable Resources Conference, September
15-20, 1996, Nashville, Tennessee. Contact Phil Badger,
205-386-3086 or 205-386-2963(fax) for technical information; Bonnie Watkins,
205-386-2925 or 205-386-2963(fax) for conference logistics. For trade show
information, contact, William Miller, 919-927-1770 (fax to same number). For
information about the ASAE event, contact ASAE, 2950 Niles Road St. Joseph, MI
49805-9659, 616-429-0300 or 616-429-3852(fax)
First Conference of the Short-Rotation Woody Crops Operations Working Group,
September 23-25, 1996, Paducah, Kentucky, sponsored by
Short-Rotation Woody Crops Operations Working Group, U.S. Department of Energy,
Oak Ridge National Laboratory, USDA Forest Service Souther Research Station
with a tour sponsored by Westvaco Corp. For conference information, contact
Wilma McNabb at the previously listed address.
For more information concerning the SRWC Operations Working Group, please
contact Bob Perlack, Box 2008, Oak Ridge, TN 37831, 865- 574-5186, 865-574-8884
(fax), Email: perlackrd@ornl.gov or
Bryce Stokes, Devall Drive, Auburn University, AL 36849, email:
stokes@so4702.usfs.auburn.edu, 3340 826-8700, 334-821-003(fax).
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