Sustainable Land & Watershed Management Interventions and Impact Workshop. Hilton Hotel, Addis Ababa, May 10, 2013.

1. Does water harvesting irrigation
technologies induce fertilizer use among
smallholders? Evidence from Ethiopia
[Agricultural systems 114(1): 54-63]
ESSP-IFPRI Workshop on:
Sustainable Land and Watershed
Management Interventions and Impact
May 10, 2013

2. Motivation
Crop production in Ethiopia: largely rain-
fed (~ 95% of the cultivated land)
Rainfall shortage, unpredictability:
production risk
Consequences: food shortage, poverty
Ethiopia implemented several programs
to improve food security since 1970s
Community soil-water conservation; R&D
to increase yield (e.g. seed varieties from
EARO)
1/15

3. motivation…
But, could not succeed to bring radical
changes on yield. Yield is low even by SSA
standard. Why is the low yield?
low modern input use (e.g. low fertilizer
use: (39% in 2007/08, Spielman et al 2011)
Various factors precondition the use of
fertilizer (e.g. price, access/SS, water)
Rainfall shortage could be a reason for the
ineffectiveness of fertilizer & the
improved seed varieties from R&D
2/15

4. motivation…
To remedy rainfall shortage (reduce
weather risk), WHTs introduced 2000s
WHTs has several advantages:
affordable, locatable, individually
owned, fit to the tenure system
If so, does WHTs induce the use of
modern input e.g. fertilizer?
3/15

5. motivation…
4/15
Types of WHTs: ponds,
shallow-wells, diversions

6. motivation…
 Previous studies: focused on non-water
factor/inputs (e.g. fertilizer price)
 Especially, microeconomic studies neglected
the interaction between water use and
fertilizer use (requires explicit investigation)
5/15

7. Objective
Investigate if the use of water harvesting
induces the use of fertilizer use by
smallholder farmers;
See if fertilizer use stimulates the use of
WH; and, the other way round as well
6/15

8. Theoretical highlight
 Microeconomic theory: Input demand is a
function of input and output prices
 In developing countries: imperfect market
and weather risk (e.g. Sadoulet & de Janvry)
 So, fertilizer demand depends not only on
its price and other factors
 Von Liebig’s Agronomic principle of Law
of the Minimum (de Wit; Paris: 1992)
 Theory of technology adoption and the
agronomic principle (control the timing of
fertilizer application) again: joint adoption 7/15

9. Methods
 Descriptive analysis: No. of fertilizer user and
non user households-(than the fert. quantity)
 Econometric analysis:
a) analyzing the effect of WHT on
fertilizer use: RE probit with WH
dummy, conditional on other factor
b) Analyzing the joint adoption of WHT
and fertilizer: bivariate probit model
(simultaneous equation)
 Data: panel data- 2005 & 2010 (400hhs)
8/15

10. Results
9/15
Users of fertilizer Non-
users of
fertilizer TotalOnly on
irrigated
plots
On both
irrigated &
rain-fed
plots
Only on
rain-fed
plots
Year 2005
Users of WHTs 12 33 102 185 332
Non-users of
WHTs
- - 15 53 68
Total 12 33 117 238 400
Year 2010
Users of WHTs 6 51 119 59 235
Non-users of
WHTs
- - 90 75 165
Total 6 51 209 134 400

11. results…
The RE estimate indicated that:
WHTs increase the probability of using
fertilizer (in any of the estimates)
Significant parameter estimates
(positive marginal effect of WHT)
In the estimate that tested joint adoption:
Past WHT use increases the probability
of current fertilizer use but past fertilizer
use does not affect current WHT use;
10/15

12. results…
Farm-size, farm capital, education:
increase the probability of using
fertilizer but fertilizer price, distance to
market decrease
Market, perennial, education, distance
to water source affect adoption of WHT
On the other hand, the hypothesis that
fertilizer use induces the use of WHTs is
rejected
11/15

13. Discussions with farmers (facts on the field)
12/15

14. discussions …
13/15

15. Conclusions
Low fertilizer use rate (39%) might not
only be due to price and other
conventional factors
Water as a precondition to modern input
use is critically important
The affordable, replicable and locatable
WHTs induce fertilizer use, in line with
both the agronomic & economic
principles
14/15

16. conclusions…
To lift the low fertilizer use rate,
encourage irrigation, (similar to other
both developed and developing
countries’ experiences) e.g….
To sustain the WHTs: Role of R&D, PS,
the govt., NGOs, local institutes, farmers
The effect of road infrastructure and
education: urge the need to continue
with the investments
15/15

17. Thank you.