1. Agronomic Studies and Cost-effectiveness of Zinc Biofortification in Ethiopia
Hae Koo Kim1, Hugo De Groote1, Samuel Gameda1,
Demissie Belayneh1*, and Nilupa S. Gunaratna2
1* Presenter, International Maize and Wheat Improvement Center (CIMMYT)
1 International Maize and Wheat Improvement Center (CIMMYT)
2 Harvard TH Chan School of Public Health

2. Zinc Deficiency in Ethiopian Soils
Ethiopian soils are deficient in zinc, potentially contributing to high zinc deficiency in the population
Would addition of zinc to fertilizer improve yields and grain zinc content in key staples?
Will it be cost-effective?
Map: Ethiopian Soil Information System (EthioSIS)

3. Methods: Agronomic Trials
Objective:
Evaluate the effect of zinc formulations and application regimens on yield and grain zinc content of important staple crops and varieties on zinc-deficient Ethiopian soils
Pot trials:
Multiple ongoing trials at two research sites
Melkassa: semi-arid agroecology, Central Rift Valley
Bako: sub-humid agroecology, west of Addis Ababa
Maize, now the major crop in Ethiopia
At each site: 2 local zinc-deficient soils x 2 popular locally-adapted maize varieties (one conventional and one quality protein maize variety)

4. Methods: Agronomic Trials
On-farm trials:
Sponsored by GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit)
Ongoing trials in Tigray, where soils are highly zinc deficient
Wheat, teff, and barley: key staples in Ethiopia
Foliar application
Farmer-managed

5. Results: Pot Trial in Bako
Spend a little time explaining the 8 fertilizer treatments. The grouping helps. The 2nd control is the current recommendation.

6. Results: Pot Trial in Bako
Yield:
Fertilizer has high potential to increase yields on Ethiopian soils
Given the limitations of a single pot trial, fertilizer treatments were not significantly different for yield

7. Results: Pot Trial in Bako
Grain zinc:
While fertilizer without zinc increases yield, it does not increase grain zinc
Addition of ZnSO4 at nationally recommended levels to basal fertilizer increases grain zinc
However, we see further gains in grain zinc when additional ZnSO4 is applied later in crop development (side-dressing or foliar application)
There are smaller effects when using ZnO (currently not available in Ethiopia) or seed priming (less likely to be adopted by farmers)
However, fertilizer regimen effects vary significantly by soil and variety

8. Results: Pot Trial in Bako
Application of ZnSO4 at later stage – as side-dressing and especially through foliar application – results in high leaf zinc content
Important for livestock nutrition, and may benefit human nutrition as well
In both grain and leaf, bioavailability must be determined
In collaboration with EPHI, Harvard, and others
Other pot trials are ongoing

9. On-Farm Trials
Foliar application also demonstrates potential to improve grain zinc in other key cereals on Ethiopian soils

10. On-Farm Trials

11. Conclusions Our preliminary findings indicate:
Blended ZnSO4 in the basal application increases grain zinc
Additional ZnSO4 as side-dressing or through foliar application further increases grain zinc, with potential benefits for human and livestock nutrition
Foliar application of ZnSO4 may provide benefits for livestock nutrition

12. Next Steps Further pot studies and on-farm trials are ongoing
Larger scale on-farm evaluation of treatment regimens is needed on varying soils, crops, and varieties
Bioavailability of increased zinc levels must be established
Laboratory analyses are planned using cell-based assays
These studies provide evidence for national fertilizer recommendations and policy discussions

13. Acknowledgements
Ethiopian Institute of Agricultural Research (EIAR), in particular Melkassa Agricultural Research Center (MARC)
Oromia Agricultural Research Institute (OARI) at Bako
Bill and Melinda Gates Foundation
GIZ