How Agro-food System Structure impacts on the Nitrogen Cascade · How Agro-food System Structure...
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How Agro-food System Structure impacts on the Nitrogen Cascade: Lessons learned from the long term analysis of the French hydro-agro-food system (1850-2050) NITROGEN, A cross-cutting Environmental Challenge Vienna, 27 februari 2019 Gilles Billen 1 , Julia Le Noë 1,2 , Josette Garnier 1 1 CNRS / Sorbonne-Université, Paris (France) 2 Institute of Social Ecology, BOKU, Vienna (Austria)
Transcript of How Agro-food System Structure impacts on the Nitrogen Cascade · How Agro-food System Structure...
How Agro-food System Structure impacts on the Nitrogen Cascade:
Lessons learned from the long term analysis of the French hydro-agro-food system (1850-2050)
NITROGEN,A cross-cutting Environmental ChallengeVienna, 27 februari 2019
Gilles Billen1, Julia Le Noë1,2, Josette Garnier1
1 CNRS / Sorbonne-Université, Paris (France)2 Institute of Social Ecology, BOKU, Vienna (Austria)
aquifer
river
River network
estuary
Flood plain
riparianwetland
agriculture
Ville
costal sea
atmosphere
dam and reservoir
Pond and lakecity
Drinking water nitrate contamination
Atmospheric pollutionGreenhouse gas emission
Coastal eutrophication
N2
Agriculture:Providing soil with nutrients to enhance, and compensate for, their export throughharvest. = Intentional introduction of « new » reactive N
Because of the mobility of N, this initiates a Nitrogen Cascade, contaminating all environmental compartments.
Vorführender
Präsentationsnotizen
The N cascade and more prceisely the N losses to the environment are one of the most on of the major enviroenmental
Bifurcations in the N cascadeProcesses which determines whether N flows toward
either desirable and useful,
or dispersive and non-manageable
pathways.
635
304
12
207
70261318
9185
Based on examples from the long term trajectory of French agriculture (1850-2015) (Le Noë et al., 2018)
0
50
100
150
200
0 100 200 300 400
Surp
lus,
kgN
/ha/
yr
total soil N inputs, kgN/ha/yr
0
50
100
150
200
0 100 200 300 400N
Yie
ld, k
gN/h
a/yr
total soil N inputs, kgN/ha/yr
The fate of fertilizersHarvest or loss?
fert
ilisa
tion
yiel
d
cropland
Harvest
N cascade
Surplus (= N balance)
Y = Ymax. F/(F+Ymax)
Yield vs Fertilisation relationship(over the whole crop rotation cycle)
Ymax=300
Total N soil inputs
0
20
40
60
80
100
0 100 200 300 400N
UE,
%total soil N inputs, kgN/ha/yr
Surplus
N Use Efficiency
Intensification isthe first cause of N losses
and low NUE
Ymax=500
Ymax, kgN/ha/yr
< 200200-400400-600600-800> 800
Br
N-PdC
L Am
LCL Av
Pic
B
Al
S
A
CCDL
MSM
COGde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L
0
50
100
150
200
250
0 100 200 300
Yiel
d, k
gN/h
a/yr
Total N inputs, kgN/ha/yr
Eure-et-Loir (Ht Loir)
700
0
50
100
150
200
250
0 100 200 300
Yiel
d, k
gN/h
a/yr
Total N inputs, kgN/ha/yr
Loire Aval
465
0
50
100
150
200
250
0 100 200 300
Yiel
d, k
gN/h
a/yr
Total N inputs, kgN/ha/yr
Yonne ('petites terres')
300
0
50
100
150
200
250
0 100 200 300
Yiel
d, k
gN/h
a/yr
Total N inputs, kgN/ha/yr
Ile de France 650
0
50
100
150
200
250
0 100 200 300
Yiel
d, k
gN/h
a/yr
Total N inputs, kgN/ha/yr
Poitou-Charente
370
0
50
100
150
200
250
0 100 200 300
Yiel
d, k
gN/h
a/yr
Total N inputs, kgN/ha/yr
Gers
500
In the same pedo-climaticcontext, organic crop rotations have similar Y vs F relationshipas conventional ones
Conventional Organic
Cropping systems
AlfAlf
Alf
WhTrit
Flax
Lent
WhBarl
Rape
Wh
Barl
0
50
100
150
200
0 50 100 150 200
Yiel
d , k
gN/h
a/yr
N input, kgN/ha/yr
0
50
100
150
200
0 100 200
Yiel
d, k
gN/h
a/yr
total soil N input, kgN/ha/yr
Picardy
400
800
2012
1852
0
50
100
150
200
0 100 200
Yiel
d, k
gN/h
a/yr
Total soil N input, kgN/ha/yr
Burgundy
400
200 2012
18520
50
100
150
200
0 100 200
Yiel
d, k
gN/h
a/yr
total soil N inputs, kgN/ha/yr
Brittany
300
600
2012
1852
The historical trajectory of regional French cropping systems
0
50
100
150
200
1850 1900 1950 2000Yi
eld
, kgN
/ha/
yr0
50
100
150
200
1850 1900 1950 2000
N in
put c
rop,
kgN
/ha/
yr
200
1852
Post 1980
1980
An unprecedent intensification of cropping systems since the mid 20th century, with limited NUE improvements since the 1980’s.
Post 1980 situations
0
20
40
60
80
100
0 20 40 60 80 100 120 140 160 180ob
serv
ed le
achi
ng, k
gN/h
a/yr
surplus N, kgN/ha/yr
The fate of the surplusSoil storage or loss?
fert
ilisa
tion
yiel
d
cropland
Surplus (= N balance)
SoilOM pool
soil storage
leaching
denitrification
Leaching vs Surplus relationship(over the whole crop rotation cycle)
cropland withcover crop
Leaching is the major fate of surplus, unless conditions are met for significantsoil OM storage (grassland, covercrops, …)
Billen et al. (2013); Vertès et al. (2007).
fert
ilisa
tion
yiel
d
cropland
Surplus (= N balance)
SoilOM pool
soil storageleaching
denitrification
in-streambenthicretentionAquifers
denitrificationin riparianwetlands
N2, N2O
N2, N2O
N2, N2O
riverDelivery at the outlet
The fate of N leaching‘retention’ or delivery at the watershed outlet?
1900 1950 2000
15
10
5
0
Nitr
ate
, mgN
/l
How large is hydrosystem retention?
0
100
200
300
400
1850 1900 1950 2000
Soil
N b
alan
ce, k
tonN
/yr Paris
River Seine network
Clay & clayed rockBasalt & rhyoliteLimestoneChalkGneissGraniteSandstoneMicashistOphioliteSandSchist & ShaleLoess
0
100
200
300
400
1850 1900 1950 2000
N o
utpu
t flu
xes,
kto
nN/y
r export at outletin stream retentionriparian retentionaquifer retentionsoil denitrificationN soil sequestration
0 100 200 km
The case of the Seine watershed
Export to the sea1/3 of N surplus
Billen et al. (in press) HEC
Denitrification in soil & riparian wetlands1/3 of N surplusStorage in soil OM and aquifers1/3 of N surplus
The fate of harvestFood or feed? (The human diet issue)
nb LU
livestockpermanent & semi-natural
grassland
PopulationAnimal pdcts
Vegetal pdcts
ferti
lisat
ion
yiel
d
cropland
surplus
NH3
foodfeed
0.0
0.1
0.2
0.3
1850 1900 1950 2000
conv
effi
cien
cy
Historical mixed crop & livestockfarming sytems
Intensive specializedlivestock farmingsystems
Low efficiencyLarge losses
Vorführender
Präsentationsnotizen
Let we come back to agricultural production. What is the fate of N imbedded in harvest? One major bifurcation there is between human nutrition or animal feeding. Because of the very low conversion efficiency of vegetal to animal protein, this bifurcation is of great importance with respect to the N cascade: animals occasionate large N losses to the atmosphere.
The status of animal farming in 19th c. traditional agriculture
5
Population1.5 M inhab
3.4
1
3.2
2.4
21
0.717
25
3
17
3
-1
cropland
14 320 km²
42
5
N Surplus
Animal pdctsVeg. pdcts
Grassland1266km²
29
728
0.7
1
Urban sludges
Livestock0.3
LU/haUAA
Export animal prdcts
Export vegetalprdcts
Symb N fix, atm depos
1852
The case of Picardy, 1852 kgN/ha/yr
FishMilkMeatVegCereals
Die
t, kg
N/ca
p/yr
Grass based mixed crop & lvstck farmingFodder based mixed crop & lvstck farming
Fodder legumes ensure most N fertilization;Animals convert fodder into manure
Alf/Clo
Wh
Barl
End 19th century: necessary connection between crop and livestock farming
Vorführender
Präsentationsnotizen
La fertilité des sols agricoles dans ce système dépend clairement des animaux, qui constituent certes une sourced de protéine animales (lait viande) le moyen de traction, mais surtout le moyen d’assurer la restitution au sols arables des nutriments prélevés par la récolte.
1909: Fritz Haber discovers the process of ammonia synthesis from atmospheric N2 and H2
Industry becomes able to massively introduce reactive N into the biosphere
N2 + 3 H2 2 NH3 NO 2 HNO 3hightemperaturehighpressurecatalyst
→ → →
Industrial fixation of atmospheric nitrogen
1913: Carl Bosch brings the process at industrial scale
Vorführender
Präsentationsnotizen
Le concept d’anthropocène est né du constat que l’homme est devenu un agent biogéochimique majeur, bouleversant de manière quantitative le cycle des principaux éléments biogènes. De ce point de vue , la perturbation du cycle de l’azote est l’exemple le plus frappant, ce qui permet de dater précisément le début de l’Anthropocène: on a le choix des dates: 1903: découverte du procédé en laboratoire qui permet de fixer l’azote atmosphérique, inerte, en azote réactif, ammoniacal ou nitrique; 1909 : dépôt par Fritz Haber et Carl Bosch du brevet du procédé, qui servira d’abord pour fabriquer des explosifs, ce qui permettra le massacre de 18 M pers en Europe pendant la première guerre mondiale, ensuite pour faire des engrais.
Second half 20th century: Agriculture becomes dependent on Chemical Industry
Vorführender
Präsentationsnotizen
30 ans plus tard, après Haber Bosch, tout a changé: …
1852
Picardy 2010, kgN/haUAA/yrPicardy 1852, kgN/haUAA/yr
1970 20101955
Stockless cropping systems
Territorial specialization of agriculture Grass-based mixed crop & livestock farmingFodder-based mixed crop & lvstck farmingSpecialized cropping systemsDisconnected crop & livestock systemsIntensive specialized livestock systems
5
Population1.5 M inhab
3.4
1
3.2
2.4
21
0.717
25
3
17
3
-1
cropland
14 320 km²
42
5
N Surplus
Animal pdctsVeg. pdcts
Grassland1266km²
29
728
0.7
1
Urban sludges
Livestock0.3
LU/haUAA
Export animal prdcts
Export vegetalprdcts
Symb N fix, atm depos
22
Population2 M inhab
8.9
5.4
3.5
7
25
3.2102
3311
15
4
6
Cropland
11 780 km²
131
8
N Surplus
Animal pdcts
Vegetal pdcts
grassld1687km²
26
1540
2.1
1Urban sludges
Livestock0.4
LU/haUAA
Export animal pdcts
Export vegetal pdcts
Symbiotic fix& atm depos
3
112
Syntheticfertilizers
1852
Grass-based mixed crop & livestock farmingFodder-based mixed crop & lvstck farmingSpecialized cropping systemsDisconnected crop & livestock systemsIntensive specialized livestock systems
1970
Britanny 2010, kgN/haUAA/yrBritanny 1852, kgN/haUAA/yr
1980 2010
Specialized livestock farming systems
Territorial specialization of agriculture
75
Population3.2 M inhab
4.3
7
4.5
59
77
20
138
10
95
5
11
Cropland
14 950 km²
101
15
Surplus N
Animal pdcts
Veg pdcts
grassld1900km²
19
9
19
1Urban sludges
Export animal pdctsSymb N fix &
atm depos
5
62
197
Synthfertilizers 111
Import feed
Export veg pdcts
38
33
Livestock1.6
LU/haUAA
Population2.3 M inhab
3.4
1.0
3.2
2.2
17
Export animal pdcts
0.5
248
11
5
4
Cropland
14 483 km²
20
5
Animal pdcts
Veg Pcdts
Grassld9677km²
8
1027
2
0.7
1
Urban sludges
Livestock0.28
LU/haUAA
Symb Fix & atm depos
N Surplus
Densité bétailUGB/ha SAU
< 0.50.5-0.750.75-11-1.5> 1.5
MaghrebAsie min
25
8040
Espagne, Portugal, Italie
25 23 30
25
17 Benelux, Allemagne, UK et autres EU28
Amerique Latine
88
Asie
112
32
20
Flux d’azote totalktonN/an
1052
Le Noé et al. (2016). Cahiers Agricultures
Extreme opening of the French agro-food system (2006)
B, G, UK
Spain,Port,Italy Lvstck dens.
LU/haUAAN fluxesktonN/yr
Vorführender
Präsentationsnotizen
La céréaliculture est essentiellement tournée vers l’exportation, vers le Maghreb à partir des ports de Rouen, vers l’europe du Nord, vers l’europe du sud pour le mais du Sud-Ouest. La Bretagne nourrit de ses productions animales bas de gamme le reste du pays, mais dépend pour ce faire d’importations massives de soja brésilien ou argentin. Au total la France exporte à peine plus de protéines sous forme de céréales qu’elle n’en importe sous forme de soja.
The need for crop and livestock farming reconnectionThe exemple of the Brie region (East of Paris)
1955: mixed crop and dairy farming
2016: Stockless cropping system
Garnier et al (2016). Envir Sci & Policy
150
2016: stockless cropping system
2016: A few organic farm, withstockless cropping systems
2025?: Possible organic mixed crop& lvstck system
2016: organic stockless farm
The fate of human excreta‘Elimination’ or recycling?
PopulationAnimal pdcts
Vegetal pdcts
N2, N2O
wastewatertrtmt plant
cropland
hydrosystemEsculier, Le Noë et al, 2018. JoH
Current fate of human excreta in Paris City kgN/cap/yr
4.7 5.3
3.1
0.22.0
Sludge recycling
Other waste
0.6
CH3OH
Vorführender
Präsentationsnotizen
Today, the human excreta of a city such as Paris are collected in sewers together with all domestic wastewater and rainfall, treated in centralized wastewater trtmt plant, were org matter is first mineralized, the N is denitrified with added ethanol as an electron acceptor. The process requires 1ton fuel equivalent per ton N eliminated, ie about the same energy as initially required for producing this ton of reactive N through the Haber Bosch process. Only a few percent of the treated N is recycled to agriculture as sludge.
PopulationAnimal pdcts
Vegetal pdcts
wastewatertrtmt plant
cropland
hydrosystemEsculier, 2019. Thesis
Source urine separation
4.7
3.8
1.5
Other waste
0.6
0.5Sludge recycling 1
Ecosanitation: source urine collection
Vorführender
Präsentationsnotizen
Yet, because most of N and P excreted by humans are present in urine, it would be technically easy to recycle most of it by a selective collection of this product before it is mixed with wastewater.
Tentative Conclusions (1)The levers to control the N Cascade?
□ The introduction of reactive N into the biosphere and its dispersion into all environmental compartements has become a major thread at the planetary scale
□ A number of steps and bifurcations of the N cascade completely escape social management, being controlled by purely bio-physical processes.e.g. soil and wetland denitrification
ammonium volatilizationnitrate leaching
□ Other steps are completely under human control, but changing them requires deepstructural changes in the socio-ecological organization of the agro-food system,Including diversification of crop rotation with better use of legume crops
reconnection of animal and crop farmingreconnection of food production and consumptiondietary change toward less animal proteinrecycling of human excreta
Dreaming of another future? A world without Haber-Bosch
An agro-ecological scenario for France in 2050
Activation of 3 levers
Billen, Le Noë & Garnier, 2018. STOTEN
1. Human diet
2. Reconnection of livestock and crop farming
3. Generalization of organic farming
635
304
12
207
70261318
9185
1. Human diet
635
304
12
207
70261318
9185 43
322
150
76661
374
4975
158
Demitarian diet (Barsac declaration ) (http://www.nine-esf.org)
2018g/cap/dayg/cap/day
kgN
/cap
/yr
demitarian
35%
veg
etal
65%
ani
mal
60%
veg
etal
40%
ani
mal
Current French system Agro-ecological Scenario
0
2
4
6
8
1850 1900 1950 1960 1970 1980 1990 2000 2010
kgN
/cap
/yr
fishdairy productsmeatfruits and vegetablescereals
Billen, Le Noë & Garnier, 2018. STOTEN
2. Reconnection of livestock and crop farming
Livestockdensity, LU/ha UAA
< 0.50.5-0.750.75-11-1.5> 1.5
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
% perm. grasslandin total agric. area
0 - 1010 - 2020 – 4040 - 60 60 - 80> 80
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
Livestock everywhere at the densitypermitted by local feed production, min 33% from permanent grassland. No import of feed!
Current French system Agro-ecological Scenario
3. Generalization of organic farming
Long and diversified crop rotations, with legume cropsNo synthetic fertilizersRe-cycling of urban excreta
Current French system Agro-ecological Scenario
AlfAlf
Alf
WhTrit
Flax
Lent
WhBarl
Rape
Wh
Barl
Short crop rotations, Synthetic fertilizersPesticides
Population62 inhab
232145
29
Export Importvegetal pdcts
540
Cropland
183 445 km² 2192
grassland93330 km²
livestock18.6 lu
Export animal pdcts
1888
Synthfertilizers 436
Symb Nfix& atm dep
Current French system:
Synthetic N fertilizers 2000 ktonN/yr
Imports 25% of livestock feed as soybeansExports 25% of its vegetal production as cereals
Population75 inhab
135
273
3
Export (or other use)vegetal pdcts
222
Cropland
180 682 km² 1550
grassland97 930 km²
livestock12 lu
Export animal pdcts
Symb Nfix
1170
365
344
Agro-ecological Scenario
No Synth N fertilizers ; Symb N fixation; urban recycling
No feed importExport of cereal (40% of current export)
ktonN/yr ktonN/yr
An agro-ecological scenario for France in 2050
Current French system
Br
N-PdC
L Am
LCL Av
Pic
B
Al
S
A
CCDL
MSM
COGde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L
< 0.450.45 – 2.252.25 – 5.655.56 – 11.3>11.3
NO3, mgN/l
Bio-Local-Demitarien
Agro-ecological Scenario
< 0.450.45 – 2.252.25 – 5.655.56 – 11.3>11.3
NO3, mgN/l
kgN/ha/yr< 3535 - 5050 - 6565 - 80> 80
N surplus
River concentration
Assessing losses to the hydrosystem
Br
N-PdC
L Am
LCL Av
Pic
B
Al
S
A
CCDL
MSM
COGde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L
Assessing greenhouse gas emissions by the agricultural sector
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
Agro-ecological scenario
N2O emissionkgN-N2O/km²/yr
<5050 - 7575 - 125125 - 175 175 - 250 > 250
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
Current French System
0 - 10001000-20002000-30003000-4000 4000-6000> 6000
CH4 emissionkgC-CH4/km²/yr
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
N-PdC
L Am
LCL Av
Pic
S
CCDL
MSM
Gde L
Gd J
AR
I-D-A
Gd MG-HGarPOcc
Lan
Gir
VC
AL
POrr
IdFE
E&L AlBr
A
CO
B
Nitrous oxide
Methane
Net Carbon dioxideCO2 net emissionkgC-CO2/ha/yr
>-200-200 to -100-100 to 00 to 100100 to 200200 to 300300 to 400400 to 500> 500
Garnier et al., 2019 STOTEN
Le Noë et al, in press Frontiers
Garnier et al., 2019 STOTEN
ktC-CO2equ / yr ktC-CO2equ / yr9000 3850
ktC-CO2equ / yr ktC-CO2equ / yr15200 8950
ktC-CO2equ / yr ktC-CO2equ / yr7400 2650
0
50
100
150
0 10 20 30 40
tota
l N lo
sses
, TgN
/yr
total trade, TgN/yr
2009
1961
Popul
3 109 inhab
11
3.6
7
3.635
Syntheticfertilizers
12
Symbioticfixation & deposition
Cropland
10 106 km²
Animal pdct
Vegetal pdcts
TgN/yr
fisheries0.4
Internationaltrade
World, 1961
2.5
13
2415
10
Grassland31 106 km²
14
52livestock0.5 109 lu
48
2.5
2.5
Popul
3 109 inhab
11
3.6
7
3.635
Syntheticfertilizers
12
Symbioticfixation & deposition
Cropland
10 106 km²
Animal pdct
Vegetal pdcts
TgN/yr
fisheries0.4
Internationaltrade
World, 1961
2.5
13
2415
10
Grassland31 106 km²
14
52livestock0.5 109 lu
48
2.5
2.5
« Feeding the world »? Can this scenario be generalized at the global scale?
Lassaletta et al., ERL 2016
Population
7 M inhab
31
12
19
1162
Syntheticfertilizers
97
Symbioticfixation & deposition
Cropland
12 106 km²
Animal pdct
Vegetal pdcts
TgN/yr
fisheries1.7
Internationaltrade
World, 2009
21
1.4
88
7540
26
Grassland34 106 km²
36
118
105
livestock1.2 109 lu
20
20 1.4
36
2009
1961
Vorführender
Präsentationsnotizen
Dernier point. Ce type de scénario n’est il pas un scénario égoïste, pour pays riche? La population mondiale atteindra 9 M en 2050. Pour répondre à leurs besoins alimentaire il faut accroitre la prod agricole, et il est plus efficace, meilleur pour la planète, de le faire là où les conditions pédo climatiques sont favorables (chez nous donc!) et de compter sur le commerce international pour re distribuer les pdts agricoles là où on a a besoin. Plutôt que de produire localement de tout partout dans de moins bonnes conditions. Voici comment fonctionne le monde aujourd’hui, avec un commerce international qui intéresse plus du quart de la prod agricole totale, et dont près de la moitié de la production agricole est destinée à l’alimentation du bétail. Depuis 50 ans, les pertes d’azote ont augmenté parallèlement avzc l’accroissemnt du commerce international. Il y a un gd nombre de scénarios possible pour nourrir le monde en 2050. Nous en avons étudié deux: Le premier est la traduction d’un scénario éonomique, qui lié l’agriculture et le régime alimentaire humain au PIB. Spécialisation, intensification, conduisent à accroitre considérablement le commerce international eet la pollution. Le second, basé sur les mêmes principe que le scénario bio-loal et demitarien que nous avons élaboré pour le BP, est un sc de souveraineté aliemntaire, Il permet de nourrir le monde avzc nettement moins de commerce international et nettement moins de pollution. Penser global c’est manger local (et bio)
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« Feeding the world »? Can this scenario be generalized at the global scale?
* Diet according to GDP in each country* Animal production specialized by country, with feed trade* Synthetic fertilisation adjusted to the needs and economicalpossibilities of each country, with environmental regulations* International trade fills the uncovered needs
2050 BAU scenario based on economic trends (SRES A1)
Lassaletta et al., 2016 ERL
Bodirsky et al, 2014 (MAgPIE model)Valin et al, 2014
2050 agro-ecological, food-sovereignty scenario* Equitable diet (4 kgN/cap/yr, 40% animal)* Ruminant production adjusted to grass production (+20% fodder production) * Symbiotic fixation adjusted to the needs and agronomical possibilities of each country by systematic introduction of legume crops in the rotations; recycling of human excreta* International trade fills the uncovered needs with excedents producedelsewhere over local requirements
Vorführender
Präsentationsnotizen
Dernier point. Ce type de scénario n’est il pas un scénario égoïste, pour pays riche? La population mondiale atteindra 9 M en 2050. Pour répondre à leurs besoins alimentaire il faut accroitre la prod agricole, et il est plus efficace, meilleur pour la planète, de le faire là où les conditions pédo climatiques sont favorables (chez nous donc!) et de compter sur le commerce international pour re distribuer les pdts agricoles là où on a a besoin. Plutôt que de produire localement de tout partout dans de moins bonnes conditions. Voici comment fonctionne le monde aujourd’hui, avec un commerce international qui intéresse plus du quart de la prod agricole totale, et dont près de la moitié de la production agricole est destinée à l’alimentation du bétail. Depuis 50 ans, les pertes d’azote ont augmenté parallèlement avzc l’accroissemnt du commerce international. Il y a un gd nombre de scénarios possible pour nourrir le monde en 2050. Nous en avons étudié deux: Le premier est la traduction d’un scénario éonomique, qui lié l’agriculture et le régime alimentaire humain au PIB. Spécialisation, intensification, conduisent à accroitre considérablement le commerce international eet la pollution. Le second, basé sur les mêmes principe que le scénario bio-loal et demitarien que nous avons élaboré pour le BP, est un sc de souveraineté aliemntaire, Il permet de nourrir le monde avzc nettement moins de commerce international et nettement moins de pollution. Penser global c’est manger local (et bio)
Conclusion (2)Revisiting Haber-Bosch legacy?
□ The rapid adoption of the Haber-Bosch process as the basis of the ‘Green Revolution’ in the second half of the 20th century has moved the global agri-foodsystem towards an exclusively industrial and capitalistic trajectory,
…post-poning by one century the development of more sustainable agro-ecologicaloptions.
« …the lives of around half of humanity are made possible by Haber–Bosch nitrogen »Erisman et al., 2008.
□ These options would allow feeding the growing global population at a reasonable(and equitable) diet, composed of a maximum share of 40% animal protein.
Vorführender
Präsentationsnotizen
We don’t know however what would have happened if the Haber-Bosch process had not been invented! Maybe the simple agro-ecological practices that we re-discover today would have been developped more rapidly. Maybe Haber-Bosch has initiated an hegemonic and exclusive socio-ecological trajectory that we now, one century later, have many difficulties to escape! From the perspective I adopted in this talk, this might be viewed as a terrible waste of time
• Anglade J, Billen G, Makridis T, Garnier J, Puech T et Tittel C. (2015). Nitrogen soil surface balance of organic vs conventional cash crop farming in the Seine watershed. Agricultural Systems 139:82-92.
• Billen G., Le Noë J., Garnier J. (2018). Two contrasted future scenarios for the French agro-food system. Science of the Total Environment 637–638: 695–705. doi.org/10.1016/j.scitotenv.2018.05.043.
• Esculier F., Le Noé J., Barles S., Billen G., Créno B., Garnier J., Lesavre J., Petit L., Tabuchi J.-P. (2018). The biogeochemical imprint of human metabolism in Paris Megacity: a regionalized analysis of a water-agro-food system. J. Hydrol. Doi.org/10.1016/j.jhydrol.2018.02.043
• Garnier J., Anglade J., Benoit M., Billen G., Puech T., Ramarson A., Passy P., Silvestre M., Lassaletta L., Trommenschlager J.-M, Schott C., Tallec G. (2016). Reconnecting crop and cattle farming to reduce nitrogen losses in river water of an intensive agricultural catchment (Seine basin, France). Environmental Science and Policy. 63: 76–90. doi.org/10.1016/j.envsci.2016.04.019
• Garnier J., Le Noë J., Marescaux A., Sanz-Cobena A., Lassaletta L, Silvestre M., Thieu V., Billen G. (2019). Long term changes in greenhouse gas emissions of French agriculture (1852-2014): from traditional agriculture to conventional intensive systems”. Sci. Tot. Environ. Doi.org/10.1016/j.scitotenv.2019.01.048.
• Lassaletta L., Billen G., Garnier J., Bouwman L., Velazquez E., Mueller N.D., Gerber J.S. (2016). Nitrogen use in the global food system: Past trends and future trajectories of agronomic performance, pollution, trade, and dietary demand. Environ. Res. Lett. 11 (2016) 095007 doi:10.1088/1748-9326/11/9/095007
• Lassaletta L., Billen G., Grizzetti B., Garnier J., Leach A. M., Galloway J.N. (2014). Food and feed trade as a driver in the global nitrogen cycle: 50-year trends. Biogeochemistry, 118: 225-241, doi.org/10.1007/s10533-013-9923-4
• Le Noë J., Billen G., Lassaletta L., Silvestre M., Garnier J. (2016). La place du transport de denrées agricoles dans le cycle biogéochimique de 1 l’azote en France : un aspect de la spécialisation des territoires. Cahier agri., 25, 15004, doi.org/10.1051/cagri/2016002
• Le Noë J, Billen G, Garnier J (2017). How the structure of agro-food systems shapes nitrogen, phosphorus, and carbon fluxes: the Generalized Representation of Agro-Food System applied at the regional scale in France. Science of the Total Environment 586: 42–55. doi.org/10.1016/j.scitotenv.2017.02.040
• Le Noë J., Billen G., Esculier F., Garnier J. (2018). Long term socio-ecological trajectories of agro-food systems revealed by N and P flows: the case of French regions from 1852 to 2014. Agriculture, Ecosystems and Environment 265: 132–143. doi.org/10.1016/j.agee.2018.06.006
• Le Noë J., Billen G., Mary B., Garnier J. (2019). Drivers of long-term carbon dynamics in cropland: a bio-political history (France, 1852–2014). Environmental Science and Policy. 93: 53–65. doi.org/10.1016/j.envsci.2018.12.027
• Le Noë J, Billen G, Garnier J. (2019). Carbon dioxide emission and soil sequestration for the French agro-food system: present and prospective scenarios. Frontiers in Sustainability (in press)
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