Seminar on Landscapes in a Carbon Focused World 26 October 2012 SIANI, Focali & Naturskyddsföreningen organized a one-day seminar in Gothenburg. Summary: Grassland for silage, hay and pasture has for long been the traditional roughage feeding strategy for cattle in northern Europe. There is an increasing interest for substituting this with maize silage and more concentrates which probably lead to different soil carbon balances. There are great difficulties to calculate such changes in estimates of GHG emissions from livestock production systems which will be discussed in this section. Christel Cederberg's research is mainly about environmental impact of livestock production systems in developed countries and focus on GHG emissions and land-use issues. Cederberg has a Master in Agriculture, a PhD in Environmental Science and now works at SIK and is adjunct professor at Chalmers.

1. Potentials for soil carbon sequestration
in different livestock feed strategies
Christel Cederberg
SIK, the Swedish Institute for Food and Biotechnology
Department of Energy and Environment, Chalmers
University of Technology
Focali 26 oct 2012
Chalmers University of Technology

2. Feeding livestock
~ 75 % of world agricultural land
23%
12%
65%
Arable land,
human food
Arable land,
feed for
livestock
Permanent
pasture,
livestock

3. Calculating the carbon footprint of milk
Primary production TransportProcessing Packaging Retail & consumer
CO2 x 1
CH4 x 25
N2O x 298
CO2 x 1 CO2 x 1 CO2 x 1 CO2 x 1
0
0,2
0,4
0,6
0,8
Primprod Process Pack Transport Retail&cons
CO2
CH4
N2O
kgCO2eperkgmilk
0.8
0.6
0.4
0.2
0
Prim prod Processing Packaging Transport Retail&cons.
CO2
CH4
N2O

4. -1000
-500
0
500
1000
1500
2000
Milk
Meat
Accounting for affected systems – total emissions globally
553 Mtonnes milk
34 Mtonnes meat
Dairy sector:
GHG emissions (Mtonnes CO2e)
associated with the dairy sector
290 Mtonnes CO2e ‘saved’~
Meat
dairy
sector
Meat
cow-calf
system
Gerber et al., 2010
Gerber et al., 2010

5. Agricultural GHG emissions 1990-2020
(no LULUC)
Källa: Smith et al 2007. Agriculture, Ecosystems and Environment 118: 6-28.
0
1000
2000
3000
4000
5000
6000
7000
8000
1990 2005 2020 1990 2005 2020 1990 2005 2020
Developing countries Developed countries Total
miljonertonCO2e/år
Biomass burning,
CH4&N2O
Manure management,
CH4&N2O
Rice cultivation, CH4
Enteric fermentation,
CH4
Soils, N2O

6. Global technical mitigation potential by 2030 in global
agriculture
Smith et al, 2007 Phil Trans R Soc 363:789-813; IPCC 2007
-200
0
200
400
600
800
1000
1200
1400
1600
MtonCO2e/year
Lustgas
Metan
Koldioxid
Close to 90% of mitigation
potential in 2030 is estimated to
be Soil Carbon Sequestration!

7. Soil carbon sequestration: Some basics
Carbon
storage,
Ton C
per ha
TIME
Arable soil
at
equilibrium
Measure:
conversion from
cropland to
grassland
Soil C sequestration
Carbon sink
saturation
10 to 100 years…….
Carbon sink
permanence
?

8. Affects soil carbon sequestration
• Carbon input
– crop residues
– organic material (e.g. manure)
• Initial carbon stock in soil
• Temperature
• Clay content
• Water content
• Carbon/Nitrogen ratio
• Tillage(?)

9. Carbon in harvest products and crop
residues
-8
-6
-4
-2
0
2
4
6
C in
harvest
C in crop
residues
Ton
C/ha

10. Important limitations for soil carbon
sequestration as a GHG mitigation option
• Carbon sink saturation – soils reach C saturation
after 20-50(100) yrs
• Achieved C sequestration is reversible – the same
land use must go on ”forever” to avoid C loss
• Displacement effects – e.g. if peatlands are taken
out of production to reduce GHG emissions,
foregone food production must take place
elsewhere, maybe by ploughing grasslands
(releasing carbon) or on deforested land
• Monitoring – verification that a particular
measure has increased soil carbon stock is costly

11. • C sequestration potentials in feed production

12. Energy from grain
Protein
pulses
Protein
Co-products
from oil
crops
Syntetiska aminosyror för snabb
tillväxt
Enmagade djur – generellt om deras foderFeeding monogastric animals

13. Cropland management for increased
C sequestration
• Agronomy practices >higher yields >more crop
residues (e.g. extending crop rotations with perennial
crops) ~0.88 t CO2/ha*yr
• Improved nutrient management ~0.55 tCO2/ha*yr
• Minimal – no tillage ~0.5 t CO2/ha*yr
• Agroforestry ~0.5 t CO2/ha*yr
• Land cover change, cropland to native
vegetation/grassland ~3 t CO2/ha*yr
Smith et al, 2007 Phil Trans R Soc 363:789-813; IPCC 2007

14. Idisslare – generellt om deras foder
Energy and proteins from
grassland
Energy from
grains Protein
from
oil seed
crops
Feeding ruminants

15. Observed effects on C-seq in
grassland soils
Net C seq (+) or
emission (-)
t CO2e/ha yr
Referens
Variable C stock change, several studies +13 till -6 Soussana m fl (2010)
Predicted range, C stock change,
European grasslands
+6 till -2a Janssens m fl (2005)
Conversion cropland to pasture +3,7 Conant m fl (2001)
Conversion cropland to grass +1,8 Soussana m fl (2004)
Conversion more leguminous plants +1,1 till +1,8 Soussana m fl (2004)
Conversion from short to permanent
grasslands
+1,1 till +1,5 Soussana m fl (2004)
Increased duration ley/grassland +0,7 till +1,8 Soussana m fl (2004)
Improved pasture management +1,3 Conant m fl (2001)
Fertilisation +1,1b Conant m fl (2001)
Reduction of N-input +1,1c Soussana m fl (2004)
Higherplantdiversity in grasslands +15 till +2,1 Steinbeiss m fl (2008)
Management of grasslands for C
sequestration
Cederberg m fl 2012. Jordbrukets potential som kolsänka, SIK-report in publication

16. Milk and beef can be produced with different
feed rations…..effects on soil carbon changes?
0,00
0,10
0,20
0,30
0,40
0,50
0,60
0,70
0,80
Baseline Maize & grass More&Better
Grass
kgDMfeedperkgmilk
Concentrates
Grain
Super-pressed pulp
Maize silage
Grass/clover silage, pasture
Production level
9000 kg
milk/cow*year
Wirsenius & Cederberg, ”Soil carbon sequestration as a greenhouse gas mitigation option in dairy
production”, manus in prep

17. Experiences from modelling soil C changes for
different feed rations in milk production
• Initial soil carbon status is very important for
the soil´s carbon sequestration potential
• The estimated soil carbon changes are
significant, but not of great importance for
milk´s total GHG balance
• Feed rations with more maize silage seem to
loose soil carbon
• Reasonably correct data on crop residues from
grasslands are needed – big lack of data!

18. Landscape focus with a carbon approach
• Develop knowledge and
understanding on
carbon fluxes and stocks
• System analysis, going
from product and farm
level to landscape level -
up-scaling?... Interaction
effects?…….
• Risk for displacement
effects?

19. Thank you!