Intensive

EX-ANTE FARM-SCALE ANALYSIS OF THE IMPACTS
OF LIVESTOCK INTENSIFICATION ON GREENHOUSE
GAS EMISSIONS OF MIXED CROP-LIVESTOCK
SYSTEMS IN WESTERN AFRICA
J. Vayssières, C. Birnholz, N.J. Hutchings and P. Lecomte
6th GGAA, February 2016, Melbourne
DEMOGRAPHIC GROWTH AND
NUTRITION TRANSITION
Africa’s population will represent 20% of the world population by 2050
(ONU, 2004; Delgado, 2003)
HIGH IMPACT LEVEL

GHG balance of livestock products in SubSaharan Africa (SSA)
(Gerber et al, 2013)
SCIENTIFIC CHALLENGE

GHG balance of livestock systems in SSAfrica is a real
scientific challenge:
Limited knowledge (N/C cycles, emissions rates) (Vayssières & Rufino, 2012)
(Ida et al, 2015)
 Complex systems (mixed systems, multiple interactions)
(Audouin et al, 2015)
 Large diversity (from pastoral to intensive systems)


Question: In which magnitude livestock intensification
can mitigate the impact of SSA livestock systems on
climate change?
3 OBSERVATORIES
STUDY CASE
The study area:
3 OBSERVATORIES
The study area:
2 LIVESTOCK SYSTEMS IN THE GROUNDNUT BASIN OF SENEGAL
Traditional extensive system
Intensive fattening system
livestock
livestock
manure
crops
feeds
crops
FARM SCENARIOS
Traditional syst.
Livestock housing
Feed ration
Manure management
Soil-Crop fertilization
Crop rotation
No housing by day and
picketed by night
Grazing fallow/crop residues
on crop fields (no concentrate
feed)
(no manure collection and
storage)
Direct deposition during
grazing and, Night penning
Millet-groundut-fallow (3
years)
Intensive syst.
Improved intensive syst.
Stable (fattening)
Stable (fattening)
Trough/stall feeding
Forage/roughage
Concentrate feed
Trough/stall feeding
Forage/roughage
Concentrate feed
Manure Heap
Covered manure Heap
Broadcast
Millet-groundnut
(2 years, no fallow)
Incorporated into soil
(with residues)
association Millet/Cowpeagroundnut (2 years)
(In Bold mitigation options)
(Grange et al., 2015)
FARM SCENARIOS
Crop-livestock systems
2TLU/ha
Traditional syst.
Livestock housing
Feed ration
Manure management
Soil-Crop fertilization
Crop rotation
No housing by day and
picketed by night
Grazing fallow/crop residues
on crop fields (no concentrate
feed)
(no manure collection and
storage)
Direct deposition during
grazing and, Night penning
Millet-groundut-fallow (3
years)
Intensive syst.
Improved intensive syst.
Stable (fattening)
Stable (fattening)
Trough/stall feeding
Forage/roughage
Concentrate feed
Trough/stall feeding
Forage/roughage
Concentrate feed
Manure heap
Covered manure heap
Broadcast
Millet-groundnut
(2 years, no fallow)
Incorporated into soil
(with residues)
association Millet/Cowpeagroundnut (2 years)
(In Bold mitigation options)
(Grange et al., 2015)
FARMAC MODEL (1)

FarmAC
a “simple” and “generic” stock-flow model at farm scale
 representing the nitrogen (N) and carbon (C) cycles

(Hutchings et al., 2013)
FARMAC MODEL (2)
Deposition
Fixation
Fertilizer
Manure
NO
33
NO
NH
2
NH33,N
, N20,N
2O
Storage
NH3, N O
losses
Exported
NH3, N2O
NH
2
NH33,N
, N20,N
2O
Exported
NH3, N2O
Runoff
NO3
Exported
NH3, N2O
NH
2
NH33,N
, N20,N
2O
(Hutchings et al., 2013)
FARMAC MODEL (3)
Fertiliser
Manure
CO
23
NO
Storage
NH3, N O
losses
Exported
NH3, N2O
CH
4,CO
2
NH
3, N2O
Exported
NH3, N2O
Runoff
NO3
Exported
NH3, N2O
CH
4,CO
2
NH
3, N2O
CH
4,CO
2
NH
3, N2O
(Hutchings et al., 2013)
NITROGEN INPUT AND OUTPUT FLUXES
200
150
kg N. ha-1
100
50
0
-50
-100
-150
Traditional
Intensive
Improved Intensive
FULL NITROGEN BALANCE
Livestock intensification
Scenario
N balance
(kg N.ha-1)
N efficiency
(dmnl)
Nutrient conservation
Traditional
Intensive
Improved
Intensive
3.4
16.3
38.3
0.57
0.69
+21%
0.74 +26%
GHG BALANCE
Traditional
4%
9%
Intensive
2%
-7%
10%
5%
-7% 3%
47%
24%
75%
Improved
Intensive
47%
31%
11%
6%
6%
Enteric methane emissions
Manure methane emissions
Manure N2O emissions
Field N2O emissions
Change in C stored in soil
Total indirect emissions
6%
GHG BALANCE
Livestock intensification
Nutrient conservation
Intensive
Improved
Intensive
Balance
Traditional
kg CO2- eq. ha-1
2900
4750 +64%
4700 -02%
kg CO2- eq. kgLW-1
55.0
25.1 -36%
24.8
-01%
Kg CO2- eq. kgN of
edible product-1
80.6
37.0 -54%
33.2
-10%
CONCLUSIONS

Take into account multifunctional dimension of livestock:
producing meat
 producing cereals !


Joint analysis of N/C cycles and GHG balance to better access
the effectiveness of technical option(s) at farm level:
impact allocation  - 50 to 60% (N limited systems)
 interactions between options (multiple steps)



“Livestock intensification” (yes !) but
“Livestock intensification + N conservation techniques” (yes !!!)
Less impact on CC (-10% more)
 more food (+7% more proteins)
 More $
 Etc.

MANURE IS A KEY RESOURCE !