The use of agroforestry principles to grow
woody biomass for bioenergy in southern
Ontario, Canada - A case study using
tree-based intercropping as an example.
Rémi Cardinael1, Naresh Thevathasan, Andrew Gordon,
Derek Sidders2, Tim Volk3, Indirs Mohammad and John Mann
School of Environmental Sciences
University of Guelph, Guelph, Ontario
Canada N1G 2W1
1AgroParisTech,
75231 Paris cedex 05, France
2 Canadian Wood Fibre Centre, NRCan.
3SUNY, Syracuse
Agroforestry Tree-Based Intercropping Alley
2m
2m
Competitive Zone
15 m
Complementary Zone
11 m
2m
Competitive Zone
Competitive Zone
Complementary Zone
•
•
•
•
•
•
•
•
• competition for moisture,
light and nutrients
enhanced nutrient cycling
enhanced nitrogen mineralization
larger additions of soil organic carbon
increased earthworm activity
improved carbon assimilation
lower soil temperature
lower evapotranspiration
reduced wind turbulence
Using Marginal Land
Sustainability
Agroforestry Intercropping Systems
15 m
11 m
Increased yields
for C3 plants
(soy, wheat, barley)
Sustainability
Using Marginal Land
Agroforestry Intercropping Systems
15 m
11 m
Complementary
Zone
Competitive
Zone
2m
Planting Willow SRWC Fields
Salix Maskiner SRC Step Planter
Planting Willow SRWC Fields
Salix Maskiner SRC Step Planter
Guelph Agroforestry Research Station
25 July 2006
12 weeks after planting
Short Rotation Woody Crops (SRWCs)
Hybrid Poplar
Shrub Willow
Soil parameters for both fields – 2006
Field
Texture
Sand, silt, clay
(%)
Soil C – total,
inorganic and
organic
pH
EC (mS.m-1)
Agroforestry
51.1, 34.7, 14.2
3.15, 1.84, 1.31
7.4
95.8
Control
53.4, 33.0, 13.6
3.29, 1.86, 1.43
7.5
89.9
None of the measured soil parameters were significantly different between
the two fields (t-test, p>0.05).
Biomass yields
Field and Clone
Willow Biomass
(odt ha-1y-1)
Agroforestry
9882-41
SV1
SX67
Control
9882-41
SV1
SX67
4.86*
2.82 b
5.64 ac
6.12 a
3.02*
2.24 b
4.50 c
2.31 b
16
14
yield (odt/ha)
12
10
8
6
4
2
0
0
1
2
3
date (year)
Agroforestry Field
Control Field
4
Willow biomass yield between an agroforestry intercropping experiment and a
monocropping system in June 2009, three years after coppice.
mean yield (odt/ha/year)
6.00
5.00
a
4.00
b
3.00
2.00
1.00
0.00
Agroforestry Field
Control Field
Belowground root biomass
Below ground root biomass (0-20cm)
• In the top 20 cm of soil, root biomass was 3000
kg ha-1 in the agroforestry field, and 2500 kg ha-1
in the control field (planting density was about
20 000 stools ha-1).
Root biomass in SRWCs
kg/ha
0
300
400
500
600
700
800
Depth (cm)
-5
-10
-15
-20
-25
Agroforestry Field
Control Field
900
1000
1100
Belowground root biomass for the three
clones
root biomass (kg/ha)
4000
3500
3000
2500
Agroforestry Field
2000
Control Field
1500
1000
500
0
9882-41
SV1
Clone
SX67
Leaf litter inputs
Willow leaf inputs (mean value per trap per day)
trap dm = 30 cm)
0.50
0.45
Leaf input (g/day)
0.40
Agroforestry 9882-41
0.35
C ontrol 9882-41
0.30
Agroforestry SV1
0.25
C ontrol SV1
0.20
Agroforestry SX67
0.15
C ontrol SX67
0.10
0.05
0.00
18Jun
2Jul
16Jul
30Jul
13Aug
27Aug
10Sep
Date
24Sep
8Oct
22Oct
5Nov
19Nov
Leaf inputs by clones across both sites
2500
Leaf input (kg/ha)
2000
1500
1000
500
0
9882-41
SV1
Clone
SX67
Leaf litter inputs:
Agroforestry (1900 kg ha-1) > monocrop (1550 kg ha-1)
2250
Leaf input (kg/ha)
2000
a
b
1750
1500
1250
1000
750
500
250
0
Agroforestry
Control
• Differences in belowground root biomass,
leaf litter inputs and biomass yields
between clones followed the same order:
SV1>SX67>9882-41 – grand mean from
both sites
Soil Organic Carbon (SOC)
Soil parameters for both fields – 2006
Field
Texture
Sand, silt, clay
(%)
Soil C – total,
inorganic and
organic
pH
EC (mS.m-1)
Agroforestry
51.1, 34.7, 14.2
3.15, 1.84, 1.31
7.4
95.8
Control
53.4, 33.0, 13.6
3.29, 1.86, 1.43
7.5
89.9
None of the measured soil parameters were significantly different between
the two fields (t-test, p>0.05).
Changes in SOC by willow
SOC changes between 2006 and 2009
2.5
(%)
2
1.5
Agroforestry
Control
1
0.5
0
2006
2009
Year
Influence of clones on soil organic C build up across both sites
Organic carbon (%)
2.00
a
1.95
a
1.90
1.85
1.80
b
1.75
1.70
1.65
9882-41
SV1
Clone
SX67
Organic Carbon (%)
Soil organic carbon build up in
2009
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
Agroforestry Field
Control Field
Willow Harvest in 2009
Willow harvest in 2009
Moisture content at harvest (Dec. 2009) = 41.3%
Over winter drying, moisture content in June 2010 = 10.43%
Re-growth in 2010 after Dec. 2009 harvest
Re-growth in 2010 after Dec. 2009 harvest
Conclusions
• The complementary interactions observed in a treebased intercropping system has helped to enhance, soil
organic C and biomass yields of all three tested clones
• It appears that a close correlation exists between
belowground root biomass, litterfall and willow biomass
yield.
• All three parameters followed: SV1>SX67>9882-41
• For landowners adopting agroforestry land-use systems,
this study provides an “option selection” – SRWC.
• Winter drying has proven effective to bring down the
biomass moisture content to levels suitable for end-use
processing
Acknowledgements
• Mr. Derek Sidders, Canadian Wood Fibre Centre,
NRCan., for his continued support and financial
assistance towards the harvest
• Dr. Tim Volk, SUNY, Syracuse, for his advice and
assistance towards the supply of clones, step planter
and establishment
• Funding from Canadian Biomass Innovation Network
(CBIN) and Ontario Centre of Excellence (OCE)