Irrigation's Potential to Improve Dietary Diversity, Production Diversity and Income in Sub‐Saharan Africa: Evidence from Ethiopia and Tanzania
Authors: Passarelli Simone Amanda , Bryan Elizabeth , Mekonnen Dawit 
Published: June 2021

Interventions aimed at increasing water availability for agricultural activities hold great potential for improving nutrition by increasing food production, income, water, sanitation and hygiene (WASH) conditions, and women's empowerment. There is scarce evidence on the linkages between small‐scale irrigation and the pathways through which nutrition outcomes can be achieved. Using data from a cross‐sectional household survey collected between 2014 and 2015 from 439 and 451 households in Ethiopia and Tanzania respectively, we explore the potential for small‐scale irrigation to contribute to improved diets as well as identify the pathways through which irrigation affects nutrition. We analyze data with an instrumental variable approach to estimate a simultaneous system of three equations, examining the relationships between irrigation and production diversity, household income and household dietary diversity. Results show that access to irrigation leads to improved household diet quality, as measured by the Household Dietary Diversity Score, mainly through the pathway of increasing household incomes. Irrigation is also found to increase production diversity, but we find no evidence that production diversity leads to increased dietary diversity. Our results are consistent with other studies that show how production diversity may be inversely associated with dietary diversity, potentially due to forgone productivity and profits associated with crop specialization.

Support or Funding Information

No conflict of interest. This research was funded by the United States Agency for International Development, Innovation Lab for Small Scale Irrigation and conducted at the International Food Policy Research Institute.

Regression results of a simultaneous system of equations on dietary diversity, production diversity, household income, and irrigation access in Ethiopia

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Variable
Dietary diversity
Production diversity
Total income
Irrigation

Estimate
Std. Err.
Estimate
Std. Err.
Estimate
Std. Er.
Estimate
Std. Err.

Production diversity
−0.179
(0.199)

Total income, USD
0.727**
(0.301)

Irrigation (yes=1)

1.624***
(0.354)
0.412**
(0.181)

Total land, hectares
−0.200
(0.132)
0.450***
(0.078)
0.299***
(0.043)
0.054**
(0.025)

Household Size
0.079
(0.071)
0.066*
(0.037)
0.025
(0.020)
0.003
(0.012)

Tropical livestock units (TLUs)
0.023
(0.016)
0.009
(0.014)
0.017**
(0.008)
0.002
(0.005)

Woman household head
0.602**
(0.279)
−0.509**
(0.238)
−0.228*
(0.133)
0.088
(0.079)

Education of woman respondent, years
0.022
(0.029)
0.026
(0.027)
0.005
(0.015)
0.002
(0.009)

Age of the woman respondent
−0.025*
(0.015)
0.001
(0.007)
0.003
(0.004)
−0.002
(0.002)

Household has info on marketing crop/livestock products

−0.161
(0.156)
0.134
(0.084)
0.060
(0.051)

Household has info on climate

−0.005
(0.153)
0.267***
(0.081)
0.025
(0.051)

Household has info on livestock

−0.247
(0.240)
0.009
(0.128)
−0.184**
(0.079)

Household has info on crop production

0.095
(0.284)
0.091
(0.151)
0.097
(0.094)

Ethnicity dummy
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

Village dummy
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

Distance to market (hours)
−0.104
(0.131)
−0.027
(0.133)
−0.042
(0.073)
−0.025
(0.044)

Log of elevation

4.291
(4.328)

−4.264***
(1.617)

Number of children under 5
−0.191
(0.488)

Used Improved seed on any plot

0.015
(0.112)

Used fertilizer on any plot

0.284*
(0.170)

Distance to major river, KM

−0.047***
(0.017)

Distance to surface water, KM

−0.032
(0.021)

Average depth of groundwater

0.002
(0.002)

Household has info on irrigation options and methods

0.369***
(0.061)

Constant
0.525
(2.892)
−28.345
(32.368)
8.864***
(0.330)
32.045***
(12.045)

R squared
−0.003

0.487

0.469

0.365

Standard errors in parentheses;

p<0.01,

p<0.05,

* p<0.1

Regression results of a simultaneous system of equations on dietary diversity, production diversity, household income, and irrigation access in Tanzania

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Variables
Dietary diversity
Production diversity
Total income
Irrigation

Estimate
Std. Err.
Estimate
Std. Err.
Estimate
Std. Err.
Estimate
Std. Err.

Production diversity
−0.299
(0.479)

Total income, USD
0.735*
(0.433)

Irrigation (yes=1)

1.205***
(0.259)
1.293*
(0.685)

Total land, hectares
−0.052
(0.103)
0.099***
(0.037)
0.187***
(0.040)
−0.034
(0.030)

Household Size
0.148
(0.201)
−0.024
(0.036)
−0.042
(0.041)
−0.007
(0.028)

Tropical livestock units (TLUs)
0.068
(0.067)
0.095***
(0.030)
0.039
(0.033)
0.006
(0.023)

Woman household head
0.278
(0.397)
−0.207
(0.174)
−0.466**
(0.213)
−0.094
(0.132)

Years of education of household head

0.047**
(0.024)
0.048*
(0.028)
−0.046**
(0.020)

Education of woman respondent
0.050
(0 058)
0.015
(0.026)
0.041
(0.029)
0.036*
(0.020)

Age of woman respondent
−0.002
(0.026)
0.015**
(0.006)
0.006
(0.007)
0.001
(0.005)

Distance to market (hours)
−0.088
(0.182)
0.012
(0.091)
0.143
(0.099)
−0.073
(0.075)

Household has info on marketing crop/livestock products

−0.224
(0.189)
−0.020
(0.203)
0.116
(0.146)

Household has info on climate

−0.015
(0.143)
−0.005
(0.161)
−0.394***
(0.138)

Household has info on livestock

0.328*
(0.190)
0.173
(0.204)
−0.037
(0.151)

Household has info on crop production

0.085
(0.140)
0.099
(0.149)
−0.084
(0.111)

Village dummy
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

Met with an ag extension worker

0.052
(0.140)
−0.208
(0.151)
−0.070
(0.112)

Number of children under 5
−0.593
(1.183)

Met with nutrition extension
0.506*
(0.269)

Used improved seed on any plot

0.143
(0.281)

Used fertilizer on any plot

0.116
(0.236)

Distance to major river, KM

0.020
(0.021)

Distance to surface water, KM

−0.028
(0.076)

Average depth of groundwater

−0.003
(0.007)

Household has info on irrigation options and methods

0.369***
(0.117)

Household member belongs to credit or microfinance group

2.398***
(0.550)

Constant
−5.021
(5.208)
0.710
(0.465)
12.652***
(0.556)
0.818**
(0.384)

R‐squared
0.023

0.238

0.283

−1.762

Standard errors in parentheses;

p<0.01,

p<0.05,

p<0.1