Addressing Human Zinc Deficiency through Agriculture Innovations in Ethiopia

Abstract

Zinc deficiency is a major public health problem in Ethiopia and other African countries, affecting nutrition and health outcomes particularly in young children and women of reproductive age, but some widely-used interventions such as food fortification can be less effective in reaching rural populations. Recent soil fertility mapping initiatives have identified widespread deficiencies of zinc and other micronutrients in Ethiopian soils, and the Ethiopian Government has made a high-level commitment to promoting and facilitating the use of fertilizers blended with micronutrients to increase crop yields. However, in addition to increasing yields, inclusion of zinc in fertilizer applied to certain crops can increase zinc levels in harvested foods, a process called agronomic biofortification that can potentially increase dietary zinc intake in vulnerable populations. For agronomic biofortification with zinc to have impact on nutrition and health in Ethiopia, nutrition and health objectives must be integrated with agricultural objectives in the formulation of national policies and recommendations for the use of zinc-containing fertilizers. Furthermore, while agronomic biofortification with zinc-containing fertilizers is widely believed to have the potential to positively impact nutrition and health, there is limited rigorous empirical evidence to support its large-scale use as a strategy to combat zinc deficiency and its associated adverse health outcomes. To address zinc deficiency in children and women in Ethiopia, several research activities are currently taking place, conducted by the International Maize and Wheat Improvement Centre (CIMMYT), the Harvard Chan School of Public Health (HSPH), the Ethiopian Public Health Institute (EPHI), the Internatonal Food Policy Research Institute (IFPRI), the Ethiopian Institute of Agricultural Research (EIAR), and the Gent University in Belgium. The overarching goal of theseefforts is to promote nutritionsensitive policy formulation and scale-up of zinc-containing fertilizer use, to generate evidence that will guide formulation of national policies and targeted agronomic recommendations in the near term, and to conduct the formative research necessary for rigorous evaluation of the nutritional and health impact of zinc-containing fertilizers in Ethiopia. For the AAAE meetings in Addis Ababa, we propose to present the results of the different aspects of this research over five themes: - Impact of Soil Fertility on Human Health - Integrating Nutrition and Agricultural Policies to Reduce Human Zinc Deficiency in Ethiopia - GIS analysis of potential impact of agronomic biofortification with zinc on human health using Disability-Adjusted Life Years (DALYs) in Ethiopia - Cost-effectiveness of Agronomic Biofortification to Improve Nutrition and Health Outcomes in Ethiopia - Towards a national strategy for implementation and scaling up of agronomic biofortification in Ethiopia

Full text

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

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)

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)

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

Results: Pot Trial in Bako

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

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

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

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

On-Farm Trials

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

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

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

Thank you
for your
interest!