Soil fertility management and malnutrition

Parched skin; milky eyes; dry, dull and straw-like looking or completely lost hair, weakness, unplanned weight loss and in other cases, weight gain/obesity. These are some physical evidences of malnutrition in children and adults alike; usually an outcome of abnormal nutrient intake levels (excessive, deficient or imbalanced) by the human body. This articles therefore takes a look at the rising cases of malnutrition in Zimbabwe and how soil fertility management can serve as an effective tool for reversal.

The State of Malnutrition in Zimbabwe

The World Health Organisation (WHO)¹ reports that about 462 million adults across the globe are underweight, 1.9 billion others are overweight or obese, while over 200 million children are either stunted, wasted or overweight. These are persons who by choice or unforeseen circumstances consume a little less or more of the nutrients required by the body. Thus, malnutrition, reported as one of the world’s greatest health concerns is a condition which weakens the immune system, makes affected persons more susceptible to diseases, and easy targets for death. Furthermore, it leads to slower psychological development and reduced productivity at the work place, translating to a reduced earning potential for adults². It is caused by low intake of food sometimes caused by outright food shortages or inability to purchase food due to economic and political instability, and most recently the Corona Virus pandemic.

In Zimbabwe, where agriculture contributes significantly to export earnings and economic growth, the unfortunate “double-burden” of malnutrition persists. Today, 18% of the country’s population (27.9% and 5.6% female and male population respectively) are obese while approximately 11% and 5% of the adult male and female population respectively are underweight³. An analysis of this data indicates a rise in obese over underweight cases which is because of poor economic conditions that have forced a good proportion of the country’s population to depend more on starch-based diets. The Food and Agriculture Organisation reports that despite its economic placement, the Zimbabwe agricultural sector is unable to meet country’s the nutritional needs due to declining soil fertility, low rainfalls/drought, shortage of farm workforce, low investment amongst other factors. Thus, leading to unavailability of food and consequently malnutrition. Poverty and income inequality are also causal factors that cannot be neglected, as many households are unable to afford basic food needs even when food is available.

Soil Fertility Status in Zimbabwe

Zimbabwe is categorized under five (5) agroecological zones⁴. However, changing rainfall patterns due to climate change has affected this zonation, therefore creating a mismatch between agronomic practices and existing land degradation problems. The country’s dependence on agriculture and shrinking arable land size also place its soil resources at a disadvantage. Against this backdrop, soils in Zimbabwe are consistently cultivated to meet domestic food needs and export commodity requirements, thus, leading to low organic matter content, leaching and subsequently decline in soil fertility. For example, Nitrogen, Phosphorus, Sulphur and in severe depletion cases Potassium, Magnessium, Copper and Zinc⁵ are nutrients commonly deficient in Zimbabwean soils.

Soil Fertility Management and Malnutrition

Poor soil fertility management is one of the causes of mortality, stunting and wasting in children⁵. As such, conserving and supplying soils with micro- and other missing nutrients is an effective approach to improving human health⁶. Mulching, crop residue management, appropriate fertilizer application and crop rotation are examples of soil fertility management practices that ensure soils are healthy and contain the right mix and amount of nutrients to support plant growth. These nutrients in the context of garbage-in-garbage-out are infused in the crops and then taken-up by the human body for use on consumption. This implies a direct relationship between healthy soils and healthy humans. Healthy soils are more productive in terms of producing more quantity and better quality of food required to end hunger and malnutrition.

Way Forward

Despite donor funded nutrition-focused programmes, global and regional commitments, national policies, strategies and legislations such as the ongoing efforts to revise the existing Zimbabwean Agro-ecological Zone Maps developed in 1960, malnutrition gaps still exist and may be on the rise in the country. This emphasizes the need to focus more on implementation of the right strategies such as ensuring that soil resources in the country are properly managed to provide the right nutrients that support crop growth and subsequently curb malnutrition. The following are some measures that would support soil fertility management and drive for change;

1. Investment in precision agriculture: this involves the use of drones, digital soil mapping, and soil sampling to monitor crop performance and determine crop and soil nutrient requirements. It may involve investing in and promoting the adoption of crop and site specific fertilizer blends such that the nutrients supplied to crops through fertilizers are precise to meet the crops specific needs and increase crop productivity. This is a deviation from blanket fertilization which contributes to wastage of resources. Thus, it can be concluded that precision agriculture also promotes resource use efficiency since missing nutrients are only supplied in accurate amounts.
2. Promotion of sustainable soil management practices: these are agronomic practices that support healthier soils. Examples include crop rotation as a strategy for breaking crop pest and disease cycles, crop residue management, cover cropping, mulching, crop diversification, reduced tillage, appropriate use of organic and mineral fertilizers. An effort at promoting sustainable soil management practices would be to enhance the capacity of small-holder farmers by conducting regular trainings on these practices.
3. Strengthen policy environment: this can be achieved by providing and/or supporting institutional frameworks that promote the adoption and implementation of sustainable soil management practices at national, state and communal levels. A solid policy framework would spur a web of interactions across sectors such as agriculture, environment and health to create change.
4. Conduct of a detailed national soil survey: an understanding of types and properties of soil resources in the country would serve as a guide for best crops suited for a given soil as well as the best agronomic practices to be adopted to increase productivity.
5. Dissemination of the FAO’s Voluntary Guidelines for Sustainable Soil Management and International Code of Conduct for the Sustainable Use and Management of Fertilizers: these publications are targeted at increasing productivity and improving food safety through the protection and management of soil resources as well as the safe use of fertilizers respectively. They both provide implementable frameworks that can be adopted by relevant stakeholders at national, sub-national and communal levels.

References

1. World Health Organisation (2021): Malnutrition: Key Facts. World Health Organisation website publication retrieved from https://www.who.int/news-room/fact-sheets/detail/malnutrition.
2. Africa Nutrition Chartbooks (2001): Nutrition of Children and Young Mothers in Zimbabwe. Findings from the 1999 Zimbabwe DHS Survey. ORC Macro International Incorporated, Maryland, USA. Extracted from https://dhsprogram.com/pubs/pdf/ANC14/ANC14.pdf.
3. NCD Risc (2017):  NCD Risk Factor Collaboration Report retrieved from http://ncdrisc.org/data-downloads.html
4. Manatsa, D., Mushore, T.D., Gwitira, I., Wuta, M., Chemura, A., Shekede, M.D., Mugandani R.,  Sakala, L.C., Ali, L. H., Masukwedza, G.I., Mupuro, J.M., and Muzira., N.M. (2020).  Revision Of Zimbabwe’s Agro-Ecological Zones. ISBN (In Press)  (2) (PDF) Report on Revised Agroecological Zones of Zimbabwe (in press). Available from: https://www.researchgate.net/publication/347966377_Report_on_Revised_Agroecological_Zones_of_Zimbabwe_in_press [accessed Jan 04 2022].
5. Nyamangara, J., Mugwira, L. M., Mpofu, S. E. (2000): Soil Fertility Status in Communal Areas of Zimbabwe in Relation to Sustainable Crop Production. Journal of Sustainable Agriculture, Vol 16 (2), Pp. 15-29.
6. Food and Farming Technology (2020): New Technology Helps Produce Detailed African Soil Fertility Maps. An online publication retrieved from https://www.foodandfarmingtechnology.com/news/data-analytics/new-technology-helps-produce-detailed-african-soil-fertility-map.html