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Carbon sequestration in pasture and forage systems. A. Moulin , P. McCaughey, D. McCartney, S. Bittman, M. Entz, W.F. Nuttall. Carbon sequestration in rotations with forages and pastures. Background Objectives Methods Carbon sequestration in rotations with forages - PowerPoint PPT Presentation
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Carbon sequestration in pasture and forage
systems
A. Moulin, P. McCaughey, D. McCartney, S. Bittman, M. Entz, W.F. Nuttall
• Background
• Objectives
• Methods
• Carbon sequestration in rotations with forages
• Carbon sequestration in fertilized and unfertilized pasture systems
Carbon sequestration in rotations with forages and pastures
• Greenhouse gases: nitrous oxide (N2O), methane (CH4), carbon dioxide (CO2)
• Carbon Sequestration: Carbon stored in the soil as soil organic matter
• Carbon Storage: Carbon stored in the soil as plant debris, roots, and soil organic matter
• One tonne of carbon removes 3.667 tonnes of CO2
Definitions
Carbon Sequestration in forages
• Increases of 5.4 and 9.3 Mg ha-1 in soil organic carbon (SOC) over 27 years for two studies in smooth bromegrass grassland. (Malhi et al. 1997, Nyborg et al 1994,
1998)
• 1.2 to 2.0 Mg C ha-1 yr -1 were stored on soils with poor fertility (Agro.Manger Sept 99 p 7-8)
• 0.2 Mg C ha-1 yr -1 over 20 years for intensive management of grassland. (Bruce et al 1999)
Objective
• To report organic carbon sequestered in pasture systems and rotations with forages.
• Discuss issues related to carbon sequestration in forage systems and pastures
Carbon Sinks
Atmosphere AtmosphereSoil
Management ManagementFertilizerRotationForages
TillageResidue
SinkTap Drain
Annual Cropping Systems
• Comparison of zero and conventional tillage at 200 locations in the Brown, Dark Brown, and Black soils in Saskatchewan
• Approximately 150 sites with a field comparison, 45 replicated studies, 5 detailed studies
Current Estimates of Carbon Sequestration• Published literature for zero vs
conventional tillage indicates 0.2 Mg C ha-1 yr-1 over 15 years for agricultural soils
• Research shows higher levels possible for Black soils over 15 years
Annual Crops (15 years)
Texture No-till vs Conventional
(Mg C ha-1 yr-1)
Continuous crop from
Crop-Fallow
(Mg C ha-1 yr-1)
Coarse (sand) 0.2 0.5-0.6
Medium (loam)
0.3 0.5-0.6
Fine (clay) 0.4 0.5-0.6
Carbon Sinks
Atmosphere AtmosphereSoil
SinkTap Drain
Management ManagementFertilizerRotationForages
Tillage
Forage Studies
• Forages in Rotation
• Melfort, Saskatchewan
• Glenlea, Manitoba
• Pasture Systems
• Pathlow, Saskatchewan
• Brandon, Manitoba
Melfort Rotations• Established in 1957 at Melfort,
Saskatchewan
• Silty clay soil, Thick Black soils
• Fertilized and unfertilized Fallow-Wheat-Wheat-Brome Alfalfa Hay- Brome Alfalfa Hay-Wheat
0
50
100
150
200
250
1970 1978 1982 1986 1994 1970 1978 1982 1986 1994
H6 H6 H6 H6 H6 Hu6 Hu6 Hu6 Hu6 Hu6
Rotation
So
il O
rgan
ic C
arb
on
(M
g h
a-1)
Carbon Sinks
Atmosphere AtmosphereSoil
Management ManagementFertilizerRotationForages
SinkTap Drain
Glenlea Rotations
• Established in 1993 at Glenlea, Manitoba• Clay soil, Thick Black soils• Rotations 1) wheat-pea-wheat-flax (W-P-W-
Fl); 2) wheat (under seeded to sweet clover)-wheat-flax (W.Cl-W-Fl); 3) wheat- alfalfa (two years)-flax (W-Al-Al-Fl); and 4) a restored native tallgrass prairie
• Flax phase was sampled in 1999
0
20
40
60
80
100
120
140
160
180
WPWF WScWF WAAF Native Grass
Flax Phase of Rotation 1999
Org
an
ic C
arb
on
(M
gh
a-1)
Fertilizer
No Fertilizer
Carbon Sinks
Atmosphere AtmosphereSoil
Management ManagementFertilizerRotationForages
SinkTap Drain
Pathlow Pasture
• Established in 1978 at Pathlow, Saskatchewan
• Undifferentiated medium to moderately fine textured soil, Gray soils
• Treatments 0, 45, 90, 180 Kg ha -1 N; 0, 20 kg ha-1 P; 0, 23, 45 kg ha-1 elemental S
• Sampled in 1989 and 1999
0
10
20
30
40
50
60
70
80
0-0-0 45-0-0 90-0-0 4-20-0 45-20-0 90-20-0 180-80-0 90-20-23 90-20-45
Fertilizer Rate (N-P-S) 1989
So
il O
rgan
ic C
arb
on
(M
g h
a-1)
0
2
4
68
10
12
14
16
0-0-0 45-0-0 90-0-0 4-20-0 45-20-0 90-20-0 180-80-0 90-20-23 90-20-45
Fertilizer N-P-S 1999
So
il O
rgan
ic C
arb
on
(M
g h
a-1)
0
5
10
15
20
25
30
0-0-0 45-0-0 90-0-0 4-20-0 45-20-0 90-20-0 180-80-0 90-20-23 90-20-45
Fertilizer Rate (N-P-S) 1999
So
il O
rgan
ic C
arb
on
(M
g h
a-1
)
Carbon Sinks
Atmosphere AtmosphereSoil
Management ManagementFertilizer
SinkTap Drain
Brandon Pasture
• Established in 1994 at Brandon, Manitoba• Fine sandy loam soil, Black soils• Treatments fertilized and unfertilized
bromegrass, fertilized and unfertilized alfalfa and bromegrass
• Fertilizer applied at soil test recommendations
• Sampled in 1999
0102030405060708090
Fertilized Unfertilized Fertilized Unfertilized
Alfalfa-bromegrass
Alfalfa-bromegrass
Bromegrass Bromegrass
Rotation 1999
So
il O
rga
nic
Ca
rbo
n (
Mg
ha-1
)
Carbon Sinks
Atmosphere AtmosphereSoil
Management ManagementFertilizerForages
SinkTap Drain
Carbon Sequestration in forages
• Potential carbon sequestration ranged from 5 to 15 Mg C ha-1, over a period from 15 to 20 years, depending on fertility management of forages in pasture and initial levels of soil organic carbon.