1. Closing the maize yield gap in Ethiopia: National analysis
Michiel van Dijk and Tom Morley
Imagine meeting 27 April, 2017
Contributions: Assefa Admassie, Katrien Descheemaeker, Martin van Ittersum, Roel Jongeneel, Marloes van Loon, Pytrik Reidsma, Joao Nunes Vieira da Silva, Kindie Tesfaye

2. Main findings
Technology gap (57%) makes up the largest component of the yield gap.
Economic constraints (30%) make up the second largest component of the yield gap
It is not profitable for farmers to use more fertilizer given current yield response and input and output prices.
Using improved seeds substantially increases yield.
Technical efficiency makes up 10% of the total yield gap.
Extension services have a positive (but small) effect on technical efficiency.

3. Policy messages
Expanding extension services to all farms will increase maize yield.
Improved farm management practices are required to close the technical efficiency yield gap.
Profitability analysis suggest that input and output prices are such that farmers do not have an incentive to expand production beyond the current level.
Stimulating the use of improved seeds has the potential to increase maize yield (but there might be economic constraints).
Closing the (technology) yield gap requires the diffusion of transformative technologies, policies and practices (e.g. precision farming).
Examples of new technologies: better pest and disease management, precision farming, new (drought) resistant cultivars.

4. Objectives
Integrate economic and agronomic approaches to assess yield gaps
Use the approach to analyse the constraints to maize yield growth in Ethiopia at the national level
Provide policy recommendations

5. Conceptual framework

6. Five different yield levels to benchmark farmer performance
Yield (tons/ha)
Biophysical maximum production level (climate, CO2, water)
w.l. potential
yield
Yield
gap
Best-practice + no economic constraints on inputs (on farm demonstrations)
Feasible yield
Economic yield
Best-practice + profit-maximizing
Technical
efficient yield
Best-practice
Actual yield
Observed yield at the plot

7. Policies to close the yield gap(s)
Yield (tons/ha)
Main causes
Policies
Potential yield
Yield
gap
Technology
Yield gap
Agricultural innovation system and broader institutional, technological, economic and social factors
Diffusion of transformative technologies, policies and practices
Feasible yield
Economic
Yield gap
Transaction and transportation costs.
Investment in rural roads
Domestic production of fertilizer
Economic yield
Allocative
Yield gap
Knowledge and financial constraints, risk issues and information asymmetries
Credit & insurance
Expand agro-dealer networks
Support market information
Land tenure systems
Smart input subsidies
Technical
efficient yield
Technology yield: diffusion of technologies that are not yet in use in the country, such as precision farming. Closing the yield gap is a long-term process.
Technical efficiency yield gap
Suboptimal crop management caused by knowledge, skills and information gaps.
Improve extension services
Stimulate knowledge transfer from best practice to average farmers
Actual yield

8. Yield gap measurement and estimation
Household survey,
Climate and soil
information
Stochastic frontier
analysis
Global Yield
Gap Atlas
Literature study
Best practice
Yield response function
Actual
yield
Technical efficient yield
Economic yield
Feasible yield
Water-limited
Potential
yield
Summary of data. Left hand side: water limited yield from GYGA and actual yield from LSMS-ISA.
Major part and innovation of the project is to link detailed plot, farm and spatial data that reflect economic and agronomic drivers to arrive at new insights. Key sources of information
GYGA: standardised approach to assess yield gap: spatial information on potential yield.
LSMS-ISA: new WB household surveys with very detailed data at plot, household and community level for multiple years and seven African countries (ETH, NGA, MWI, TZA, Niger, Mali, Burkina).
Yield gap decomposition

9. Data: Household survey (LSMS-ISA)
Summary of data. Left hand side: water limited yield from GYGA and actual yield from LSMS-ISA.
Major part and innovation of the project is to link detailed plot, farm and spatial data that reflect economic and agronomic drivers to arrive at new insights. Key sources of information
GYGA: standardised approach to assess yield gap: spatial information on potential yield.
LSMS-ISA: new WB household surveys with very detailed data at plot, household and community level for multiple years and seven African countries (ETH, NGA, MWI, TZA, Niger, Mali, Burkina).
Source: World Bank

10. Data: Global Yield Gap Atlas
Summary of data. Left hand side: water limited yield from GYGA and actual yield from LSMS-ISA.
Major part and innovation of the project is to link detailed plot, farm and spatial data that reflect economic and agronomic drivers to arrive at new insights. Key sources of information
GYGA: standardised approach to assess yield gap: spatial information on potential yield.
LSMS-ISA: new WB household surveys with very detailed data at plot, household and community level for multiple years and seven African countries (ETH, NGA, MWI, TZA, Niger, Mali, Burkina).
Source:

11. w.l. Potential yield (kg/ha)
Actual yield (Ya), water-limited yield (Yw) and other statistics by zone
ZONE
Yield
(kg/ha)
w.l. Potential yield (kg/ha)
Fertilizer
(%)
Nitrogen (kg/ha)
Area
(ha)
Improved seeds (%)
Extension (%)
Number
AMHARA
1,727
11,607 47
91.9
0.13 34 52
587
HARARI
850
6,361 59
51.2 14 43
162
OROMIYA
1,730
13,042 31
69.6
0.17 21 30
705
SNNP
1,860
12,362 35
64.7
0.18 27 26
574
SOMALI
1,031
10,571 2
7.8
0.32 90
TIGRAY
1,381
10,556 38
56.3
0.1 3 54
216
OTHER
1,827
12,709 4
13.2
0.23 5
318
TOTAL
1,685
11,888
71.3
0.16
2,562

12. Technical efficient yield (Yte): Extension services matter
Plots with extension services have on average ~10 pp higher technical efficiency

13. Economic yield: Not profitable for farmers to use more nitrogen
Yield response (YR) to nitrogen use ~8.4 kg maize/kg N
Value cost ratio (VCR)< 1.
But excludes 65% of farmers with N =0!
Highly depends on relative price information!
ZONE YR
VCR
Fertilizer (%)
Nitrogen (kg/ha)
AMHARA
6.2
0.61 47
91.9
HARARI
5.6
0.55 59
51.2
OROMIYA
10.0
0.99 31
69.6
SNNP
11.8
1.17 35
64.7
TIGRAY
6.3
0.63 38
56.3
TOTAL
8.4
0.83 39
72.2
World Bank (2010) YR: kg maize/kg N
Minten et al. (2013) YR: kg maize/kg N

14. Feasible yield (Yf): what if inputs would be for free?
Assumptions
50% more seeds
50% more labour
400 kg N/ha
All farmers use animal traction
All farmers use improved seeds
All farmers use manure

15. Comparison of yield levels by zone

16. Decomposition of the yield gap

17. By how much can national maize production in Ethiopia be increased when yield gaps are closed?
All yield gaps closed
economic optimal application of fertilizer
National maize production in 2013 (FAOSTAT)
All policies combined
Extension services for all plots
Application of improved seeds
Maize production 2013 ETH: 6.67 million tons (FAOSTAT)
Extension services: 0.15 million tons additional
Fertilizer: ~ 1 million tons additional
Improved seed: ~ 1.1 million tons additional
All policies: ~ 2.8 million tons additional (50 % of 2013 production).

18. Main findings
Technology gap (57%) makes up the largest component of the yield gap.
Economic constraints (30%) make up the second largest component of the yield gap
It is not profitable for farmers to use more fertilizer given current yield response and input and output prices.
Using improved seeds substantially increases yield.
Technical efficiency makes up 10% of the total yield gap.
Extension services have a positive (but small) effect on technical efficiency.

19. Policy messages
Expanding extension services to all farms will increase maize yield.
Improved farm management practices are required to close the technical efficiency yield gap.
Profitability analysis suggest that input and output prices are such that farmers do not have an incentive to expand production beyond the current level.
Stimulating the use of improved seeds has the potential to increase maize yield (but there might be economic constraints).
Closing the (technology) yield gap requires the diffusion of transformative technologies, policies and practices (e.g. precision farming).
Examples of new technologies: better pest and disease management, precision farming, new (drought) resistant cultivars.

20. Thank you
Questions?

21. Methodology to operationalise framework
Take actual maize yield from LSMS-ISA
Estimate frontier/technically efficient yield
Using stochastic frontier analysis
Compute profit maximizing fertilizer (nitrogen) use
Short run profit maximization under the assumption that capital and labour are fixed and fertilizer is variable
National level maize and fertilizer prices
Take yield potential from GYGA

22. Methodology Take actual maize yield from household survey
Use yield response function for best-practice farms/plots to estimate technical efficiency yield
Use regional maize and fertilizer prices to calculate economic yield
Estimate feasible yield using assumptions on input use
Take potential water-limited yield from GYGA
Calculate yield gaps

23. Yield levels
Potential (water-limited) yield: Biophysical maximum production level determined by CO2 emissions, solar radiation and climate (but constrained by water resources).
Feasible yield: Maximum yield that can be achieved on a plot with available technology and best-practice management assuming no economic constraints.
Economic yield: yield level at which profits are maximized.
Technical efficient yield: measures best-practice performance at each input level.
Actual yield: Observed yield at the plot level.