Addressing Human Zinc Deficiency through Agricultural Innovations in

Ethiopia

Samuel Gameda1, Hae Koo Kim1, Hugo De Groote1, Israel Bekele2, Tadesse Birhanu Atomsa3, and Nilupa S. Gunaratna4

1 International Maize and Wheat Improvement Center (CIMMYT)2 Ethiopian Institute for Agricultural Research (EIAR-MARC)

3 Oromia Agricultural Research Institute (OARI)4 Harvard TH Chan School of Public Health

Zinc in Human Health

• Zinc is an essential nutrient for human health• Zinc deficiency increases the risk of:

– Child mortality

– Diarrhea and pneumonia

– Child stunting (poor linear growth) poorer health, development, educational attainment, economic productivity in adulthood

– Pregnant women: Preterm delivery

Zinc Deficiency:A Global Public Health Problem

• Affects 17% of the population globally

• Affects 24% of the population in Africa

• Remains among the top 15 contributors to the overall disease burden in Eastern, Central, and Western Africa

Figure: Black et al. 2008

Zinc deficiency, children < 5 years

Soil Zinc Deficiency

• Zinc in the food supply ultimately traces back to the soil:– Soil zinc concentration, soil

type and characteristics (e.g., pH), soil fertility management practices

• Soil zinc deficiency can reduce the zinc content of harvested crops

Strategies to Reduce Zinc Deficiency

• Dietary diversification and behavior change

• Supplementation

– Requires financial resources and delivery infrastructure

• Food fortification

– Requires centralized food processing

• Biofortification: Improvement of the nutritional contribution of food crops

Biofortification

GeneticConventional breeding or GMTargets rural populationsCost-effectiveRequires genetic diversityRequires source of mineralsRequires more time to impact

AgronomicEnrich fertilizer, perhaps beyond yield requirementCan also improve food securityDepends on crop, variety, soil, form of nutrient, application method and timingRequires less time to impact

Agronomic Biofortification for Ethiopia

• Zinc-enriched fertilizers have improved yields and grain zinc concentration:– Wheat in Turkey– Rice in India– Maize in Zimbabwe

Agronomic Biofortification for Ethiopia

What is the potential for Ethiopia?1. Is zinc deficiency a public health concern?

2. Are Ethiopian soils zinc deficient?

3. Would agronomic biofortification increase the zinc content of important crops, and will that zinc be bioavailable?

4. What will be potential impact on health?

5. Will it be cost-effective?

6. What are the policy needs for scaling?

Agronomic Biofortification for Ethiopia

• The Ethiopian Government is introducing zinc-containing blended fertilizers and reformulating fertilizer recommendations based on soil mapping

• The goal is yield. Can the goal also be nutrition-sensitive, while being cost-effective and not compromising on yield?

• Can the rollout of the Government’s blended fertilizer program be rigorously evaluated for human nutritional impact?

Team

• International Maize and Wheat Improvement Center (CIMMYT)

• Harvard T.H. Chan School of Public Health

• Ethiopian Public Health Institute (EPHI)

• International Food Policy Research Institute (IFPRI)

• Ethiopian Institute for Agricultural Research (EIAR)

• Close coordination with the Ethiopian Ministry of Agriculture (MoA) and Agricultural Transformation Agency (ATA)

• Sponsored by the Bill and Melinda Gates Foundation (BMGF) and the United Kingdom’s Department for International Development (DFID)

Project Objectives

1. Identify areas with high potential impact, using national data on food consumption, human zinc status, agricultural production, and soil fertility

2. Identify fertilizer formulations and application methods that result in a high increase in grain zinc content for the most popular maize varieties in target areas

3. Assess the bioavailability of the increased grain zinc content resulting from application of zinc-containing fertilizer

4. Conduct a cost-benefit analysis based on potential impact on DALYs and estimation of costs

5. Develop a protocol for evaluation during scaling and rollout

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 yields were not significantly different

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• DFID

Thank you for your interest!