bianca g empirical evidence of food security and mitigation benefits july 2011
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Economics
of
sustainable
agricultural
systems
E
S
A S
Empirical evidence of food security
and mitigation benefits
from improved cropland management
by
Giacomo Branca
with
L. Lipper, N. McCarthy and M.C. Jolejole
(Agricultural Development Economics Division, FAO)
Smallholder Mitigation:
Mitigation Options and Incentive Mechanisms
Expert Workshop
Rome, June 7-8 , 2011
Economics
of
sustainable
agricultural
systems
E
S
A S
Outline
1. Key research questions
2. Data and methods
3. Results
4. Discussion
Economics
of
sustainable
agricultural
systems
E
S
A S
1. Key research questionsSustainable agriculture :
• increases crop productivity and system resilience, without resources degradation
• potential to deliver climate change mitigation co-benefits: reduced GHG emissions and increased Carbon sequestration
Where to expect highest mitigation co-benefits from changes in smallholder agriculture aimed at
promoting food security and CC adaptation (synergies)?
What are the key barriers that prevent the adoption of “climate smart” agricultural systems
(trade-offs)?
Economics
of
sustainable
agricultural
systems
E
S
A S
2. Data and methods • Empirical results from lit review (CAB Abstracts, Science Direct, Science Magazine Online, ProQuest, Economist Intelligence Unit, World Bank & OECD, WOCAT technology database)
Academic & grey literature (e.g. WOCAT: thesis, manuscripts and other unpublished work)
•English, Spanish, Portuguese; developing countries
•implementation at smallholder level: small-size farms (<1-2 ha); only a few cases medium-large scale farms
•Not included: model estimations, research station experiments, on-farm field trials, studies without quantitative impact or technology packages; research experiments included only in case of long-term/worldwide/large areas experiments
•Additional lit review (qualitative) of adoption barriers
Economics
of
sustainable
agricultural
systems
E
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A S
Meta-analysis:
Each study result is one observation (one data point in a larger dataset containing all available information)
A single publication contributed more than once if a separate study was done for different countries or if more than one crop type was studied
% change of average yields with respect to the yield under conventional agriculture (results compared with control areas)
Cereals Other crops Total
Agronomy 28 10 38
Integrated nutrient management 24 7 31
Tillage and residue management 55 15 70
Water management 44 8 52
Agroforestry 20 6 26
Total 171 46 217
Management practice n.
Economics
of
sustainable
agricultural
systems
E
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A S Effect of improved cropland management practices: average % marginal increase of cereal yields at global level (95% confidence intervals )
3. Results: synergies
121
79
106115
69
0
20
40
60
80
100
120
140
160
180
Agronomy (28) Integrated nutrient
management
(24)
Tillage and residue
management
(55)
Water management
(44)
Agroforestry (20)
Management
Practices
Details of the Practices
Cover crops
Improved crop or fallow rotations
Improved crop varieties
Nutrient
management
Organic fertilization (use of compost, animal and
green manure)
Incorporation of crop residues, mulching
Reduced/minimum/zero tillage
Terraces, contour farming
Water harvesting
Live barriers, fences
Trees on cropland
Agronomy
Tillage and residue
management
Agroforestry
Water
management
Economics
of
sustainable
agricultural
systems
E
S
A S Dry areas
116
72
122
9281
0
50
100
150
200
250
Agronomy (6) Integrated nutrient
management
(20)
Tillage and residue
management
(42)
Water management
(30)
Agroforestry (8)
122 118
55
164
61
0
50
100
150
200
250
Agronomy (22) Integrated nutrient
management
(4)
Tillage and residue
management
(13)
Water management
(14)
Agroforestry (12)
Humid areas
Economics
of
sustainable
agricultural
systems
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A S
0
20
40
60
80
100
120
140
160
Agronomy Tillage/residue management
Water management
Agroforestry
%
Asia and Pacific Sub-Saharan Africa
Source: Henao and Baanante 2006
Asia and Pacific
Average % marginal increase potential of cereal yields at regional level
Sub-Saharan Africa
Economics
of
sustainable
agricultural
systems
E
S
A S
High mitigation & food security potential in humid areas: synergies (potential to link mitigation finance)
Mitigation co-benefits smaller in dry lands – but overall impacts of changes on food security substantial (mitig. finance mainly feasible over large areas/farmers)
0100200300
Dry
0 100 200 300
Agronomy
Nutrient management
Tillage/residue management
Water management
Agroforestry Moist
Yield: average marginal increase (%/year)
GHG reduction (tCO2e/ha/year) (graph 1ton=100%)
Economics
of
sustainable
agricultural
systems
E
S
A S • SLM is key in developing “Climate-smart” productive systems:
- difference between humid and dry areas and implications for climate finance
- geographical differences: SLM more effective in SSA?
- no effect of farm size?
• Limits of the present analysis:
- limited number of crops (maize and wheat), climates (warm dry/humid, no cool climates). And mainly small farms…
- no observations reported negative responses (may be biased sample)
- limited information on the yield variability
- consistence of results differs across technologies
4. Discussion
Economics
of
sustainable
agricultural
systems
E
S
A S Expand research :
expand database of SLM and crop yields• include other crops and agro-environmental conditions
• consider grasslands and livestock
• meta-analysis of experimental data
• Consider single practices instead of technology packages
• correct biased regional representation - 60% in SSA
• Conduct analysis at farming systems/AEZ level
build databases for emission reduction coefficients by farming system/agro-ecologies
identify locations/farming systems where mitigation has highest economic returns to FS & agricultural development
4. Discussion
Economics
of
sustainable
agricultural
systems
E
S
A S
THANK YOU
for your attention!
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