Skip to main content

Widespread heterogeneity in staple crop mineral concentration in Uganda partially driven by soil characteristics

Abstract

Calcium (Ca), iron (Fe), selenium (Se), and zinc (Zn) deficiencies are widespread in sub-Saharan Africa, with severe implications for human health. In Uganda, where the predominant diet depends heavily on plant-based staples, crop mineral concentration is an important component of dietary mineral intake. Studies assessing the risk of nutrient deficiency or the effectiveness of nutrient-focused interventions often estimate dietary mineral intake using food composition tables that are based on crops grown in developed countries. However, little is known about the actual nutritional content of crops grown in Uganda. Here, we document the Ca, Fe, Se, and Zn concentration of staple crops collected from Ugandan household farms. While median mineral concentrations were similar to those reported previously, variation in crop mineral concentration was high, particularly for Fe and Se. An ordinary least squares regression showed that some soil characteristics were correlated with crop mineral concentrations. Of these, soil pH was often positively associated with crop mineral concentration, while sand and organic carbon concentrations were negatively associated with several crop mineral concentrations. However, much of the variation in crop mineral content was not associated with the soil characteristics measured. Overall, our results suggest that extensive heterogeneity in staple crop mineral concentration in Uganda is likely due to a combination of edaphic characteristics and other variables. Because staple foods constitute a large portion of dietary mineral intake in Uganda and other developing countries, these results have implications for estimates of dietary mineral intake and the development of effective intervention strategies in such regions.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14

Notes

  1. 1.

    Based on food frequency data collected in Uganda (Bevis and Hestrin 2020), the median quantity of maize porridge consumed daily by young children is estimated to be 314 g. Maize porridge contains approximately 12% raw maize flour by weight, providing 38.47 g of maize flour per meal, or 115.42 g per day (Hotz et al. 2012a).

References

  1. Alloway, B. J. (2009). Soil factors associated with zinc deficiency in crops and humans. Environmental Geochemistry and Health, 31(5), 537–548.

    CAS  Google Scholar 

  2. Barrett, C. B., & Bevis, L. E. (2015). The micronutrient deficiencies challenge in African Food Systems. In D. E. Sahn (Ed.), The fight against hunger and malnutrition: The role of food, agriculture, and targeted policies (pp. 61–88). Oxford: Oxford University Press.

    Google Scholar 

  3. Bevis, L. E., Conrad, J. M., Barrett, C. B., & Gray, C. (2017). State-conditioned soil investment in rural Uganda. Research in Economics, 71(2), 254–281.

    Google Scholar 

  4. Bevis, L. E., & Hestrin, R. (2020). Variation in crop zinc concentration influences estimates of dietary Zn inadequacy. PlosONE, 15(7), e0234770. https://doi.org/10.1371/journal.pone.0234770.

    CAS  Article  Google Scholar 

  5. Bhutta, Z. A., Das, J. K., Rizvi, A., Gaffey, M. F., Walker, N., Horton, S., et al. (2013). Evidence-based interventions for improvement of maternal and child nutrition: What can be done and at what cost? The Lancet, 382(9890), 452–477.

    Google Scholar 

  6. Black, R. E., Victora, C. G., Walker, S. P., Bhutta, Z. A., Christian, P., De Onis, M., et al. (2013). Maternal and child undernutrition and overweight in low-income and middle-income countries. The Lancet, 382(9890), 427–451.

    Google Scholar 

  7. Bouis, H. E., & Saltzman, A. (2017). Improving nutrition through biofortification: A review of evidence from HarvestPlus, 2003 through 2016. Global Food Security, 12, 49–58.

    Google Scholar 

  8. Bouyoucos, G. J. (1936). Directions for making mechanical analyses of soils by the hydrometer method. Soil Science, 42(3), 225–230.

    CAS  Google Scholar 

  9. Cakmak, I. (2002). Plant nutrition research: Priorities to meet human needs for food in sustainable ways. Plant and Soil, 247, 3–24.

    CAS  Google Scholar 

  10. Chen, C. M., Dynes, J. J., Wang, J., & Sparks, D. L. (2014). Properties of Fe-organic matter associations via coprecipitation versus adsorption. Environmental Science and Technology, 48, 13751–13759.

    CAS  Google Scholar 

  11. Chilimba, A. D., Young, S. D., Black, C. R., Meacham, M. C., Lammel, J., & Broadley, M. R. (2012). Agronomic biofortification of maize with selenium (Se) in Malawi. Field Crops Research, 125, 118–128.

    Google Scholar 

  12. Chilimba, A. D., Young, S. D., Black, C. R., Rogerson, K. B., Ander, E. L., Watts, M. J., et al. (2011). Maize grain and soil surveys reveal suboptimal dietary selenium intake is widespread in Malawi. Scientific Reports, 1, 72.

    Google Scholar 

  13. De Benoist, B., McLean, E., Egli, I., & Cogswell, M. (2008). Worldwide Prevalence of Anaemia 1993–2005: WHO Global Database on Anaemia. Geneva: World Health Organization.

    Google Scholar 

  14. Delong, G., Leslie, P. W., Wang, S.-H., Jiang, X.-M., Zhang, M.-L., Rakeman, M., et al. (1997). Effect on infant mortality of iodination of irrigation water in a severely iodine-deficient area of China. The Lancet, 350, 771–773.

    CAS  Google Scholar 

  15. Donovan, U. M., Gibson, R. S., Ferguson, E. L., Ounpuu, S., & Heywood, P. (1992). Selenium intakes of children from Malawi and Papua New Guinea consuming plant-based diets. Journal of Trace Elements and Electrolytes in Health and Disease, 6(1), 39–43.

    CAS  Google Scholar 

  16. dos Reis, A. R., El-Ramady, H., Santos, E. F., Gratão, P. L., & Schomburg, L. (2017). Overview of selenium deficiency and toxicity worldwide: Affected areas, selenium-related health issues, and case studies. In Selenium in plants (pp. 209–230). Cham: Springer.

  17. Ecker, O., Weinberger, K., & Qaim, M. (2010). Patterns and determinants of dietary micronutrient deficiencies in rural areas of East Africa. African Journal of Agricultural and Resource Economics, 4(2), 175–194.

    Google Scholar 

  18. FAO, IFAD, WFP. (2015). The State of Food Insecurity in the World 2015. Rome: FAO.

  19. Ferguson, E. L., Gibson, R. S., Thompson, L. U., Ounpuu, S., & Berry, M. (1988). Phytate, zinc, and calcium contents of 30 East African foods and their calculated phytate: Zn, Ca: phytate, and [Ca][phytate]/[Zn] molar ratios. Journal of Food Composition and Analysis, 1(4), 316–325.

    CAS  Google Scholar 

  20. Fiedler, J. L., & Afidra, R. (2010). Vitamin A fortification in Uganda: Comparing the feasibility, coverage, costs, and cost-effectiveness of fortifying vegetable oil and sugar. Food and Nutrition Bulletin, 31(2), 193–205.

    Google Scholar 

  21. Fordyce, F. M. (2005). Selenium deficiency and toxicity in the environment. In O. Selinus, B. J. Alloway, P. L. Smedley, J. A. Centeno, R. B. Finkelman, R. Fuge, & U. Lindh (Eds.), Essentials of medical geology (pp. 375–416). Amsterdam: Springer.

    Google Scholar 

  22. Foster, H. L. (1981). The basic factors which determine inherent soil fertility in Uganda. Journal of Soil Science, 32(1), 149–160.

    Google Scholar 

  23. Gray, C. L. (2011). Soil quality and human migration in Kenya and Uganda. Global Environmental Change, 21(2), 421–430.

    Google Scholar 

  24. Haase, H., & Rink, L. (2014). Multiple impacts of zinc on immune function. Metallomics, 6(7), 1175–1180.

    CAS  Google Scholar 

  25. Harvey, P., Rambeloson, Z., & Dary, O. (2010). The 2008 Uganda food consumption survey: Determining the dietary patterns of Ugandan women and children. A2Z: the USAID Micronutrient and Child Blindness Project. Washington, DC: Academy for Educational Development.

  26. Hengl, T., et al. (2017). Soil nutrient maps of Sub-Saharan Africa: Assessment of soil nutrient content at 250 m spatial resolution using machine learning. Nutrient Cycling in Agroecosystems, 109, 77–102. https://doi.org/10.1007/s10705-017-9870-x.

    CAS  Article  Google Scholar 

  27. Horton, S., Alderman, H., & Rivera, J. A. (2009). Hunger and malnutrition. Global Crises, Global Solutions: Costs and Benefits, pp. 305–354.

  28. Hotz, C., Abdelrahman, L., Sison, C., Moursi, M., & Loechl, C. (2012a). A food composition table for Central and Eastern Uganda. Washington, DC: International Food Policy Research Institute and International Center for Tropical Agriculture.

    Google Scholar 

  29. Hotz, C., Loechl, C., Lubowa, A., Tumwine, J. K., Ndeezi, G., Masawi, A. N., et al. (2012b). Introduction of β-carotene–rich orange sweet potato in rural Uganda resulted in increased vitamin A intakes among children and women and improved vitamin A status among children. The Journal of Nutrition, 142(10), 1871–1880.

    CAS  Google Scholar 

  30. Joshi, A. K., Crossa, J., Arun, B., Chand, R., Trethowan, R., Vargas, M., et al. (2010). Genotype × environment interaction for zinc and iron concentration of wheat grain in eastern Gangetic plains of India. Field Crops Research, 116(3), 268–277.

    Google Scholar 

  31. Joy, E. J., Ander, E. L., Broadley, M. R., Young, S. D., Chilimba, A. D., Hamilton, E. M., et al. (2017). Elemental composition of Malawian rice. Environmental Geochemistry and Health, 39(4), 835–845.

    CAS  Google Scholar 

  32. Joy, E. J., Ander, E. L., Young, S. D., Black, C. R., Watts, M. J., Chilimba, A. D., et al. (2014). Dietary mineral supplies in Africa. Physiologia Plantarum, 151(3), 208–229.

    CAS  Google Scholar 

  33. Joy, E. J., Broadley, M. R., Young, S. D., Black, C. R., Chilimba, A. D., Ander, E. L., et al. (2015a). Soil type influences crop mineral composition in Malawi. Science of the Total Environment, 505, 587–595.

    CAS  Google Scholar 

  34. Joy, E. J., Kumssa, D. B., Broadley, M. R., Watts, M. J., Young, S. D., Chilimba, A. D., et al. (2015b). Dietary mineral supplies in Malawi: Spatial and socioeconomic assessment. BMC Nutrition, 1(1), 42.

    Google Scholar 

  35. Karami, M., Afyuni, M., Khoshgoftarmanes, A. H., Papritz, A., & Schulin, R. (2009). Grain zinc, iron and copper concentrations of wheat grown in central Iran and their relationships with soil and climate variables. Journal of Agricultural and Food Chemistry, 57, 10876–10882.

    CAS  Google Scholar 

  36. Kennedy, G., Nantel, G., & Shetty, P. (2003). The scourge of” hidden hunger”: Global dimensions of micronutrient deficiencies. Food Nutrition and Agriculture, 32, 8–16.

    Google Scholar 

  37. Kihara, J., et al. (2020). Micronutrient deficiencies in African soils and the human nutritional nexus: Opportunities with staple crops. Environmental Geochemistry and Health. https://doi.org/10.1007/s10653-019-00499-w.

    Article  Google Scholar 

  38. Kupka, R., Nielsen, J., Nyhus Dhillon, C., Blankenship, J., Haskell, M. J., Baker, S. K., et al. (2016). Safety and mortality benefits of delivering vitamin A supplementation at 6 months of age in Sub-Saharan Africa. Food and Nutrition Bulletin, 37(3), 375–386.

    Google Scholar 

  39. Kyamuhangire, W., Lubowa, A., Kaaya, A., Kikafunda, J., Harvey, P. W., Rambeloson, Z., et al. (2013). The importance of using food and nutrient intake data to identify appropriate vehicles and estimate potential benefits of food fortification in Uganda. Food and Nutrition Nulletin, 34(2), 131–142.

    Google Scholar 

  40. Larochelle, C., Katungi, E., & Cheng, Z. (2016). Household consumption and demand for bean in Uganda: Determinants and implications for nutrition security (No. 310-2016-5485).

  41. Ligowe, I. S., et al. (2020). Selenium biofortification of crops on a Malawi Alfisol under conservation agriculture. Geoderma, 369, 114315. https://doi.org/10.1016/j.geoderma.2020.114315.

    CAS  Article  Google Scholar 

  42. Manzeke, G. M., Mapfumo, P., Mtambanengwe, F., Chikowo, R., Tendayi, T., & Cakmak, I. (2012). Soil fertility management effects on maize productivity and grain zinc content in smallholder farming systems of Zimbabwe. Plant and Soil, 361(1–2), 57–69.

    CAS  Google Scholar 

  43. Manzeke, G. M., Mtambanengwe, F., Nezomba, H., & Mapfumo, P. (2014). Zinc fertilization influence on maize productivity and grain nutritional quality under integrated soil fertility management in Zimbabwe. Field Crops Research, 166, 128–136.

    Google Scholar 

  44. Manzeke, G. M., Mtambanengwe, F., Watts, M. J., Hamilton, E. M., Lark, R. M., Broadley, M. R., et al. (2019). Fertilizer management and soil type influence grain zinc and iron concentration under contrasting smallholder cropping systems in Zimbabwe. Scientific Reports, 9, 6445.

    Google Scholar 

  45. Maziya-Dixon, B., Kling, J. G., Menkir, A., & Dixon, A. (2000). Genetic variation in total carotene, iron, and zinc contents of maize and cassava genotypes. Food and Nutrition Bulletin, 21(4), 419–422.

    Google Scholar 

  46. McIntosh, J. L. (1969). Bray and Morgan soil test extractants modified for testing acid soils from different parent materials. Agronomy Journal, 61, 259–265.

    CAS  Google Scholar 

  47. Mistry, H. D., Pipkin, F. B., Redman, C. W., & Poston, L. (2012). Selenium in reproductive health. American Journal of Obstetrics and Gynecology, 206(1), 21–30.

    CAS  Google Scholar 

  48. Morgan, M. F. (1941). Chemical soil diagnosis by the universal soil testing system. Connecticut Agricultural Experiment Station Bulletin, 450, 579–628.

    CAS  Google Scholar 

  49. Moura, D., Fabiana, F., Miloff, A., & Boy, E. (2015). Retention of provitamin A carotenoids in staple crops targeted for biofortification in Africa: Cassava, maize and sweet potato. Critical Reviews in Food Science and Nutrition, 55(9), 1246–1269.

    Google Scholar 

  50. Murata, M. R., Hammes, P. S., & Zharare, G. E. (2003). Effect of solution pH and calcium concentration on germination and early growth of groundnut. Journal of Plant Nutrition., 26, 1247–1262.

    CAS  Google Scholar 

  51. Ngigi, P. B., Du Laing, G., Masinde, P. W., et al. (2019). Selenium deficiency risk in central Kenya highlands: An assessment from the soil to the body. Environmental Geochemistry and Health. https://doi.org/10.1007/s10653-019-00494-1.

    Article  Google Scholar 

  52. Okalebo, J. R., Gathua, K. W., & Woomer, P. L. (2002). Laboratory methods of soil and plant analysis: A working manual, 2 edn. Chapter: Soil particle size analysis by the Bouyoucos or hydrometer method. Tropical Soil Biology and Fertility Programme Nairobi, Kenya.

  53. Phiri, F. P., et al. (2019). The risk of selenium deficiency in Malawi is large and varies over multiple spatial scales. Scientific Reports, 9(1), 1–8.

    CAS  Google Scholar 

  54. Prasad, A. S. (2003). Zinc deficiency. BMJ, 326(7386), 409–410.

    Google Scholar 

  55. Sahrawat, K. L., Rego, T. J., Wani, S. P., & Pardhasaradhi, G. (2008). Sulfur, boron, and zinc fertilization effects on grain and straw quality of maize and sorghum grown in semi-arid tropical region of India. Journal of Plant Nutrition, 31(9), 1578–1584.

    CAS  Google Scholar 

  56. Shivay, Y. S., Kumar, D., & Prasad, R. (2008a). Effect of zinc-enriched urea on productivity, zinc uptake and efficiency of an aromatic rice-wheat cropping system. Nutrient Cycling in Agroecosystems, 81, 229–243.

    CAS  Google Scholar 

  57. Shivay, Y. S., Kumar, D., Prasad, R., & Ahlawat, I. P. S. (2008b). Relative yield and zinc uptake by rice from zinc sulphate and zinc oxide coatings onto urea. Nutrient Cycling in Agroecosystems, 80(2), 181–188.

    CAS  Google Scholar 

  58. Supriatin, S., Weng, L., & Comans, R. N. (2015). Selenium speciation and extractability in Dutch agricultural soils. Science of the Total Environment, 532, 368–382. https://doi.org/10.1016/j.scitotenv.2015.06.005.

    CAS  Article  Google Scholar 

  59. Tidemann-Andersen, I., Acham, H., Maage, A., & Malde, M. K. (2011). Iron and zinc content of selected foods in the diet of schoolchildren in Kumi district, east of Uganda: a cross-sectional study. Nutrition Journal, 10(1), 81.

    CAS  Google Scholar 

  60. USDA. (2008). “USDA National Nutrient Database for Standard Reference, Release 21.” U.S. Department of Agriculture, Agricultural Research Service, USDA Nutrient Data Laboratory. Beltsville, MD.

  61. USDA. (2013). “USDA National Nutrient Database for Standard Reference, Release 26.” U.S. Department of Agriculture, Agricultural Research Service, USDA Nutrient Data Laboratory. Beltsville, MD.

  62. van Heerden, S. M., & Schönfeldt, H. C. (2004). The need for food composition tables for southern Africa. Journal of Food Composition and Analysis, 17(3–4), 531–537.

    Google Scholar 

  63. Walkley, A., & Black, I. A. (1934). An examination of the Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil Science, 37(1), 29–38.

    CAS  Google Scholar 

  64. Wasserstain, R. L., & Lazar, A. N. (2016). The ASA’s statement on p-values: Context, process, and purpose. The American Statistician, 70(2), 129–133.

    Google Scholar 

  65. Weil, R. R., & Brady, N. C. (2017). The nature and properties of soils (pp. 601–642). Upper Saddle River, NJ: Pearson.

    Google Scholar 

  66. Wessells, K. R., & Brown, K. H. (2012). Estimating the global prevalence of zinc deficiency: Results based on zinc availability in national food supplies and the prevalence of stunting. PLoS ONE, 7(11), e50568.

    Google Scholar 

  67. Wood, S. A., Tirfessa, D., & Baudron, F. (2018). Soil organic matter underlies crop nutritional quality and productivity in smallholder agriculture. Agriculture, Ecosystems & Environment, 266, 100–108.

    CAS  Google Scholar 

Download references

Acknowledgements

Kampala IFPRI and HarvestPlus offices provided office space and support during the collection process. Thanks are due to survey PIs Clark Gray, Ephraim Nkonya, Darrell Shultze, Chris Barrett, and Leah VanWay, to all surveyors, particularly Agaba Choice and Sentumbwe George, to Mike Rutzke, Ross Welch, Raymond Glahn, and Johannes Lehmann for guidance, to Tembi Williams, Maia Call and Tonny Bukeera for research assistance, and to Chris Barrett, David Just, Shanjun Li and various seminar participants for feedback.

Funding

Data collection was funded by the National Science Foundation (BCS-1226817), HarvestPlus, and the Cornell International Institute for Food, Agriculture and Development. Kampala IFPRI and HarvestPlus offices provided office space and support during the collection process. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Author information

Affiliations

Authors

Contributions

LB designed study and coordinated sample collection and analysis. LB also conducted the statistical analyses, with critical insight and suggestions from RH. Both authors contributed to the writing of the manuscript and approved the final version of the manuscript.

Corresponding author

Correspondence to Leah Em Bevis.

Ethics declarations

Conflicts of interest

The authors have declared that no competing interests exist.

Availability of data and material

Raw data are available upon request.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Appendix

Appendix

See Tables 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19.

Table 7 Recovery rates of NIST certified reference materials and an internal standard for ICP-AES analyses run at the Cornell Nutrient Analysis Laboratory (CNAL)
Table 8 Bean mineral concentration and soil characteristics
Table 9 Groundnut mineral concentration and soil characteristics
Table 10 Maize mineral concentration and soil characteristics
Table 11 Sorghum mineral concentration and soil characteristics
Table 12 Sweet potato mineral concentration and soil characteristics
Table 13 Cassava mineral concentration and soil characteristics
Table 14 Bean mineral concentration and soil characteristics, with pH interaction
Table 15 Groundnut mineral concentration and soil characteristics, with pH interaction
Table 16 Maize mineral concentration and soil characteristics, with pH interaction
Table 17 Sorghum mineral concentration and soil characteristics, with pH interaction
Table 18 Sweet potato mineral concentration and soil characteristics, with pH interaction
Table 19 Cassava mineral concentration and soil characteristics, with pH interaction

See Figs. 8, 9, 10, 11, 12, 13, and 14.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Bevis, L.E., Hestrin, R. Widespread heterogeneity in staple crop mineral concentration in Uganda partially driven by soil characteristics. Environ Geochem Health 43, 1867–1889 (2021). https://doi.org/10.1007/s10653-020-00698-w

Download citation

Keywords

  • Micronutrient
  • Deficiency
  • Calcium
  • Selenium
  • Iron
  • Zinc
  • Soil
  • Staple crops