Addressing malnutrition with biofortified maize in Zimbabwe: from crop management to policy and consumers

The double burden of malnutrition refers to the suboptimal intake of essential nutrients (minerals, metals and vitamins), either caused simply by inadequate dietary intake and/or due to the intake of "empty calories" i.e., food that has sufficient calories but lacks adequate amounts of essential nutrients. This double burden falls disproportionally heavy on developing countries, and there on women and children. It directly increases child mortality and childhood stunting, and reduces people's ability mending diseases. In Zimbabwe, an estimated one in four children have vitamin A deficiency, two-thirds are living with iron deficiency and one in three have iron deficiency anaemia (UNICEF, 2019). And a quarter of children (0.76 million) under five in Zimbabwe are currently stunted. Among women of reproductive age, one in four have vitamin A deficiency, six in ten women have iron deficiency and one in four are anaemic.

Malnutrition and its negative effects are particularly common in rural areas where people mostly live from their own crop production and the diet is mostly cereal based. This group is difficult to reach with supplements and has basically no access to fortified processed food. As an alternative method, plant breeders developed "biofortified" crops, meaning crops with a higher content of minerals, metals and (pro)vitamin A (PVA). However, recent research has shown that the effectiveness of such biofortified crops is a) affected considerably by soil characteristics, and that b) their nutrient content can be enhanced with micronutrient fertilizer and other crop management options. To enable making best use of the new biofortified crop varieties we propose the following research:

Work package (WP) 1: what are the effects of agronomic management options on PVA concentration and micronutrient uptake of novel, biofortified maize lines. African soils are often poor and have a low fertility, resulting in low yields and low grain quality. This can, for example, be addressed with soil conservation methods (increased return of crop residues and reduced tillage), with macro and micro nutrient treatments, or with liming. However, little is known how such treatments affect the nutrient content in the newly developed biofortified maize varieties. We will, therefore, test a range of the new varieties under several agronomic management options, to identify the best conditions and treatments for high quality, nutritious maize.

WP2. Testing the effectiveness of agronomic biofortification at the farm-scale. As mentioned above, African soils are often poor, but they are also very variable. Farmers of course know their soils well, they know where the crops grow well and where not, and they often increase soil fertility in particular fields (where they dump kitchen refuse or crop residues, where the cattle are kept at night, etc). Therefore, farmers could grow biofortified crops in preferential places but it is unknown how much this could contribute to an improved nutritional value. We will test these options with 60 farmers for two seasons for their effectiveness, feasibility, and possible impact.

WP3. Closing the nutrient gap or Predicting the effect of bio + agro fortification at the national level. Although maize is a very important staple for most people in Zimbabwe, they also eat other food. And only their total "food basket" determines their nutrient uptake. Knowledge of the food basket composition and of the nutrient content of all items in the basket allows then to estimate the possible contribution of the bio-and agro-fortified food on the nutrition of the people. WP3 will estimate this impact for all regions in Zimbabwe based on WP1 and WP2 results in combination with national statistics on food consumption and, where necessary, some additional analysis of common food items.

WP4. This WP focuses on upscaling and dissemination and has no research components.

The direct impact of our research is aimed towards enhancing the quality of life, health and well-being of people in sub-Saharan Africa (SSA). The initial focus of the project is Zimbabwe (Low Income Country on the DAC List of ODA Recipients), which has considerable micronutrient deficiency (MND) problems, but results will be is easily scalable to neighbouring countries in East Africa with a similar dependence on maize as main stable and equally wide spread micronutrient deficiencies. By developing a multidisciplinary approach combining biofortification and agronomic fortification with a dissemination and policy framework, the project will address several of the UN Sustainable Development Goals (SDGs), including the elimination of hunger (SDG2), good health and wellbeing (SDG3) and responsible consumption and production (SDG12).

Finalized and ongoing "GeoNutrition" projects in Malawi and Ethiopia are already improving our understanding of the link between soil characteristics and crop composition for Zn and Se. Our ongoing GeoNutrition project also tests micro-nutrient fertilizer treatments for maize in Ethiopia. Another project led by Rothamsted Research, the "Africa Soils Information Service (AfSIS)" has prepared digital soil maps which can be used to localize micronutrient deficiencies at a regional scale across Africa. On the other hand, CIMMYT developed provitamin A maize germplasm and released it already in Malawi, Tanzania, Zambia and Zimbabwe. Efficacy studies demonstrated that increasing provitamin A intake through consuming provitamin A maize has a positive effect on the vitamin A status of consumers. Our project brings together these different efforts to combine biofortified maize with agronomic fortification and knowledge of farmers' crop management to maximize the benefit for the health of all consumers.
The idea of combining these different approaches to maximize the nutritional quality of maize seems obvious but limited research has been conducted and is, therefore, highly innovative (partly because not many biofortified crop varieties have been released). The proposed analysis of grain quality of biofortified lines on farmers' fields with a range of soil quality levels is also novel and will allow a much better evaluation of the possible impact of the bio/agronomic fortification approach in the real environment of smallholder farmers.

From a natural sciences perspective, the data and approaches proposed in our project have the potential to shape/enhance soil and crop management decisions, and investment in breeding programmes. For example, it can inform decisions on how to prioritise R&D and deploy new traits/varieties most effectively to benefit consumers, farmers, and the wider industry. We also believe that the geospatial food basket analysis together with our results on grain quality will identify hotspots of micronutrient deficiency and enable more targeted interventions for bio/agronomic fortification. It could also provide considerable value for monitoring/testing policy interventions through a geospatial framework.

From a social sciences perspective, food systems research from both consumer (demand-driven) and producer (supply driven) perspectives could potentially be transformed by being able to account for spatial variations in food mineral compositions. The flows of some minerals (e.g. zinc, iron) through food systems can be integrated into health burden/outcome-based socioeconomic frameworks (e.g. using Disability Adjusted Life Years, DALYs). Thus, our findings can contribute immediately towards influencing public policies to address micronutrient deficiencies at local, regional and national scales, e.g. through education and dietary diversification. Our "Pathways to Impact" activities will align directly with ongoing activities of the Food and Nutrition Council, and therefore be integrated into national efforts to combat the double burden of malnutrition.