Agricultural Outlook Forum
U.S. Department of Agriculture
Presented: March 1-2, 2007
SWITCHGRASS FOR BIOMASS ENERGY: STATUS AND PROGRESS
Kenneth P. Vogel
Research Leader & Geneticist
Agricultural Research Service, USDA
Lincoln, Nebraska
SWITCHGRASS FOR BIOMASS
ENERGY: STATUS AND
PROGRESS
Kenneth P. Vogel
Research Leader & Geneticist
Agricultural Research Service,
USDA
Lincoln, Nebraska
Presented Thursday, March 1, 2007
USDA-ARS Forage & Biomass
Research Project- Lincoln,NE
• Switchgrass research 1930’s to present.
• Switchgrass
domestication – breeding
and management.
• Prior to mid-1990’s, use
by livestock had been
emphasized.
• 1990 - began work to
develop switchgrass into
biofuels crop (DOE
cooperative research)
Northern Plains Switchgrass Field
Scale Production & Economic Trials
15”-17”
Annual
Precipitation
2000-2006
On-Farm
Production
Trials:15-20 acre
fields
31”-33”
Annual
Precipitation
Energy Production in the Great
Plains – On farm economic study.
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•
•
•
•
Field shown at left had a five
year cumulative average cost
of $30/U.S. ton switchgrass
biomass including land costs.
Average costs for 10 farms
was $49/ton; experienced
farmer’s costs were $36/ton.
Economic analyses in journal
review (UNL Ag Economist)
Data from trials being used for
net energy balance analysis.
Soils sampled before & after
trials – C sequestraion
research (ARS Lincoln &
Mandan, ND.)
Switchgrass field in NE South Dakota
in 2005. Yields averaged 4 tons/acre.
Take Home Lessons
• Economic production efficiency can be improved
via research and producer training.
• Improved high yielding cultivars/hybrids with
improved conversion efficiency are needed.
• Additional agronomic research on fertility,
establishment, seed quality, & other factors.
• Feedstock harvesting and storage research
needed.
• Adaptation and production trials in other
potential biomass production areas are needed.
Switchgrass biomass energy
Current Goals & Research
• Goals
• Full establishment in 1
year with 50% yield.
• Be at full production
second year.
• Goal of 10T/A
(Midwest); improved
ethanol yield/ton.
• Fully documented
environmental benefits
• Tools and Products
• Weed control, no-till
planting, seed quality.
• Breeding - Biomass
specific cultivars & F1
hybrids, improved
conversion
• Molecular biology, cell
wall modification & seed
quality.
• Environ. studies/ C
sequestration.
Establishment & Seed Quality
• Establishment weed control
with improved herbicides
Biochemical & molecular studies on
mechanisms of switchgrass seed
dormancy and germination.
.
Different seed quality tests
Fluorescence microscopy of switchgrass
seeds incubated on FDA for 2 days
Improved seed quality &
seed quality tests
(Sarath et al., 2006. Planta
223:1154-1164)
Breeding improved grasses for biomass and
grassland production systems: multi-step process.
Germplasm evaluation
& Selection nurseries.
Polycross
Hybridization
Regional yield
Regional small plot trials
tests.
Grazing trials to document
economic value
Breeding Progress for Conventional
Switchgrass Cultivars
Yield Trial Mead, NE 2003-2005
Cultivar
Year
released
Trailblazer
1984
IVDMD
Biomass
yield
(%)
(tons/acre) (mature)
6.3
52.5
Shawnee
1995
6.5
54.8
7.4
53.8
7.0
55.2
NE 2000C1 In seed
increase
NE Late
In seed
YD C4
increase
Improve biomass yields – hybrid
cultivars
Strain
Kanlow &
Summer
F1’s
Kanlow
Summer
Yield
tons/acre
9.4
7.1
6.1
• Improved hybrid cultivars with modified cell walls could
improve ethanol yields & reduce costs.
Biorefineries and Biomass
Feedstock Quality
(source: Nebraska Ethanol Board)
Switchgrass genetic variation in stem lignin (STLIG) & digestibility (STDMD)
Regression of STLIG vs STDMD
Population:
3 cycles for
High DMD
STLIG (g/kg)
For 1550
Each graph
point is a
two year
mean of a
switchgrass
genotype
80
75
70
65
60
55
50
45
40
r²= 0.766
F=638.35
df=195
400
450
500
550
600
STDMD (g/kg)
Regression of STLIG vs STDMD for 836
Population:
1 cycle for
low DMD
STLIG (g/kg)
90
r²= 0.736
F= 547.5
df=196
80
70
60
50
40
300
400
500
STDMD (g/kg)
600
Genetic effects on lignin, anatomy & ethanol yield
from switchgrass cellulose
Thick, lignified layer
↓
Mean Ethanol Yield mg/g
80
Stem Lignin 63.2 g/kg
Eth an o l yield (m g /g
78
76
74
72
70
68
66
64
C-1 Hi Lig
Stem Lignin 50.7 g/kg
C-1 Lo Lig
C+3 Hi Lig
Population
C+3 Lo Lig
Modification of switchgrass cell walls can have
adversely fitness effect – maintaining fitness must
be part of improvement strategy.
Results of multi-cycle selection for increased forage digestibility
without selection for yield or fitness.
Means from multi-year trials at
Mead, NE, Ames, IA, and
Madison, WI.
Cycle 3 half-sib family nursery at
Mead, NE showing differential winter
kill among families.
Carbon sequestration Study- Corn vs
Switchgrass, Mead, NE
• Quantify carbon
sequestration on cropland
converted to switchgrass.
• Compare to no-till corn.
• Ten year experiment in
eastern NE established in
1998.
• In 2000, plots split and
stover removed (50%) on
split half of corn plots.
• Cooperative ARS-Ft.
Collins (R. Follett) &
NRCS National Soils Lab
ARS Switchgrass and other Herbaceous Bioenergy Crop Research
St. Paul, MN
Mandan, ND
Management
Alfalfa
Breeding
Molecular Genetics
Quality
Management
Madison, WI
Switchgrass
Other Grasses
Breeding
Management
Corvallis, OR
Gasification
Other Grasses
College Park, PA
Switchgrass
Management
Albany, CA
Switchgrass
Molecular genetics
ERRC, PA
Lincoln, NE
Gasification
Switchgrass
Other Grasses
Breeding
Molecular biology
Management
Economics
Harvest & Storage
Quality
Athens, GA
Spectroscopy
Quality
Tifton, GA
Conversion
Peoria, IL
Switchgrass
Alfalfa
Fermentation
Conversion
Other grasses
Breeding
Management
Bottom Line
• Switchgrass is an economically feasible
biomass energy crop for use on marginal
cropland.
• Improvements in genetics and agronomics
will improve:
–
–
–
–
biomass yields
biomass quality
conversion
ethanol yield per acre