Biological Sciences ︱ Felix Dapare Dakora & Glory Chinonye Mbah Legumes can help to Biological (BNF): a green agricultural technology. N2ase + eliminate trace element N2 + 8e = 8H + 16ATP 2NH3 + H2 + 16ADP + 16Pi deficiency in • Uses light energy from the sun via Nutrient-poor soils in Africa is a utrient deficiency is a major University of Technology, Pretoria, pressing issue. As a result, many health problem on a global Professor Felix Dakora is well placed photosynthesis people in the African continent Nscale, and nowhere is this issue to conduct this research. • Low carbon footprint suffer from nutrient deficiency more apparent than in Africa. Due to due to not being able to access the inherently low concentration of A BACKGROUND TO THE PROBLEM nutritious foods. This is what nutrients in African soils, exacerbated Due to the inherently low levels of makes the work of Professor by the common practice of cultivating nutrients in African soils, approximately Felix D. Dakora of Tshwane crops without fertilisers, and the removal 232 million people suffer from trace Soil known as Rhizobia form root nodules University of Technology so of left-over crop residues after grain element deficiency in the African on legumes and fix nitrogen from the air. important. His pioneering harvest, nutrient deficiency is a serious continent. Examples of common nutrients research into finding foods that problem in the continent. that people are deficient in include iron, will enable increased nutrient zinc, selenium and iodine. Trace elements in which to increase trace elements In a comprehensive study undertaken in in order to obtain a satisfactory amount consumption in the diet, and his This is where the work of Professor are chemical elements present only in peoples’ diets through increasing 2005 and 2006, Professor Felix Dakora of trace elements in the diet. This means work demonstrating that the Felix Dakora and his Research Group in minute amounts in soil and have a the consumption of certain types proved the benefits of consuming a that growing certain types of application of nitrates, typically at the Tshwane University of Technology relatively low presence in foods. Despite of vegetables over others, and has particular legume, commonly known over others for consumption has huge found in fertilisers, can actually comes into play. Professor Felix Dakora being found in low levels, these trace specifically been researching the as cowpea, as a way of increasing trace health benefits. decrease the amount of trace is at the forefront of researching elements are nonetheless important. potential for legumes to be used as a elements within the diet. In this study, the elements in certain foods, is solutions that ensure people receive way of increasing the amount of trace concentrations of trace elements within the Professor Felix Dakora’s work also of vital importance for Africa’s enough trace elements in their diets. In small doses, they are vital for brain elements that people have access leaves and grain of 27 different types of indicates that the cowpea genotypes rural populations. Funded by the Bill and Melinda Gates development and are purported to to in their diets. cowpea were assessed, and it was found that contain higher amounts of trace Foundation, the National Research reduce the risk of chronic diseases such to contain up to three times more iron than elements in their leaves are high Foundation of South Africa, the South as cancer, cardiovascular disorders and Legumes are already known for their is found in spinach! This study showed nitrogen fixers, due to their physiological African Research Chair in Agrochemurgy age-related degenerative diseases. ability to provide plant make up. This means and Plant Symbioses, and the Tshwane Their deficiency can also lead to stunted protein, but there has that they are efficient at growth, a critical issue when considering been little assessment Due to the low levels of nutrients the process previously that many children suffer from trace of the relationship in soils, approximately 232 million mentioned; and they are element deficiency in Africa. between legumes and able to accumulate large mineral accumulation people suffer from trace element amounts of nitrogen In South Africa, the problem is so prior to Professor Felix in their biomass. severe that there is now a policy of Dakora’s research. deficiency in Africa. supplementing food materials for children A legume is a type Understanding this is with trace elements such as iron, zinc and of flowering plant that has a symbiotic the potential of cowpea consumption crucial; with careful breeding of select selenium in order to meet the dietary relationship with nitrogen-fixing bacteria for preventing trace element deficiency plants, the high nitrogen-fixing trait requirements recommended by the in the soil. in rural African communities, especially could be enhanced. This research has World Health Organization. While this is within children; this has huge implications the potential to overcome trace element of course a necessary short-term solution, This means that the bacteria live in the for human nutrition and health. deficiency in rural Africa through it is not sustainable in the long-term. root systems of the plant and convert plant breeding. nitrogen gas from air in the soil into To further this research, Professor Felix Although eating seafood, dairy products ammonia, which is then used by both Dakora and his Group also studied the Significantly, this research shows that and meat can provide trace element the bacteria and the plant to grow. The concentrations of trace elements in the the consumption of legumes has great supplements to the diet, this is not a bacteria benefit from being able to live different genotypes of cowpea. Genotypes potential to decrease trace element feasible solution for poorer communities in the plant roots where they obtain food are types of the same species but with deficiency in humans. While the study in rural Africa, as these communities made by the plant for their growth, while slightly different genetic makeups. did not necessarily indicate how these cannot afford these types of foods. the plant in turn benefits from nitrogen trace elements will be processed when compounds produced by the bacteria. This research has incredible practical consumed, Professor Felix Dakora has THE POTENTIAL OF LEGUMES As a result, legumes are able to take up implications. For example, if certain paved the way for further research, in Legumes are a type of flowering plant that Due to not being able to rely on animal more mineral nutrients from the soil, thus genotypes of cowpea have higher particular to identify suitable plants that have a symbiotic relationship with nitrogen- fixing bacteria in the soil. products for nutrition, Professor Felix increasing the amount of trace elements concentrations of trace minerals, then less exhibit high levels of trace elements in Dakora has been researching ways that they contain. of their leaf matter needs to be consumed edible plant parts.

www.researchoutreach.org www.researchoutreach.org Nitrogen fixing ability of legumes. Behind the Research Soybean Groundnut % N Amount of % N Amount of from atmos. N-fixed (kg/ha) from atmos. N-fixed (kg/ha) Professor Felix Dapare Dakora 50 - 97 23 - 220 24 - 67 46 - 188 E: [email protected] T: +27 79 489 3777 W: https://www.researchgate.net/profile/Felix_Dakora

Mung Bean Cowpea Research Objectives References % N Amount of % N Amount of from atmos. N-fixed (kg/ha) from atmos. N-fixed (kg/ha) Professor Dakora’s research investigates biological nitrogen Dakora, F.D., Belane, A.K. (2019). Evaluation of protein and 66 - 86 31 - 111 50 - 96 17 - 198 fixation with a focus on the legume, the interaction between micronutrient levels in edible cowpea (Vigna unguiculata microbe and host plant, as well as the microsymbiont itself. L. Walp.) leaves and seeds. Front. Sustain. Food Syst. 3:70. https://doi.org/10.3389/fsufs.2019.00070

Pigeon Pea Kersting’s Groundnut Detail Samson B.M. Chimphango, Charles F. Musil & Felix D. % N Amount of % N Amount of Dakora (2012). Alteration in the mineral nutrition of purely Bio from atmos. N-fixed (kg/ha) from atmos. N-fixed (kg/ha) symbiotic and nitrate-fed nodulated legumes exposed to Prof Dakora completed his PhD degree in in 1989 27 - 92 42 - 400 40 - 75 23m - 102 elevated UV-B radiation. Journal of Plant Nutrition, 35:1, at the University of Western , and is currently Plant 1-20. http://dx.doi.org/10.1080/01904167.2012.631663 and Soil Biotechnology Professor at the Tshwane University of Technology in Pretoria. Prof Dakora is a recipient of the Belane, A.K., Dakora, F.D. (2011). Levels of nutritionally- UNESCO-Equatorial Guinea International Prize for Research important trace elements and macronutrients in edible THE PROBLEM WITH NITRATES in the Life Sciences; the African Union leaves and grain of 27 nodulated cowpea (Vigna unguiculata Professor Felix Dakora has done Professor Dakora has paved the way Science Excellence Award; and is a Fellow of the Academy L. Walp.) genotypes grown in the Upper West Region of additional research into the issue of trace of Science of South Africa, Fellow of the African Academy of . Food Chemistry. 125(1):99-105. DOI: 10.1016/j. for further research, showing that more foodchem.2010.08.044 element deficiency, but taking a different Sciences, as well as Fellow of The World Academy of Sciences path, which looks at the potential of needs to be done to identify suitable for the developing countries (TWAS). In 2017, Prof Dakora Belane, A.K., Makhubedu, I.T., Pule-Meulenberg, F., Dakora, adding nitrates to plants to increase was elected President of the African Academy of Sciences. F.D. (2014). Nitrogen fixation and -induced the amounts of minerals and nutrients crop plants that exhibit high levels accumulation of mineral nutrients by cowpea (Vigna that they contain. Nitrate fertilisers Funding unguiculata L. Walp.) Crop and Pasture Science. 65(3):250. are notorious for contributing both to of trace elements. The Bill and Melinda Gates Foundation, the National DOI: 10.1071/CP13283 ground and water pollution, as well as to mineral elements in their leaves, stems these plants to fix nitrogen, which is Research Foundation of South Africa, the South African global warming. Despite this, they are and roots. In many of the legumes, so desperately needed for sustainable Research Chair in Agrochemurgy and Plant Symbioses, thought of as the solution to increasing certain nutrient quantities increased; crop growth and yields. Professor Felix and the Tshwane University of Technology, Pretoria. Personal Response crop yields, and therefore food security, for example, in one species, commonly Dakora’s research has shown that certain in many situations. However, in a study known as water blossom pea (Podalyria types of plants can contribute more What further research needs to be done on trace undertaken in 2012, along with student calyptrata), the concentrations of calcium in terms of combating trace element element deficiency? researchers in his laboratory, Professor increased in all parts of the plant, while deficiency and that although nitrate use Getting beneficial soil microbes to promote greater Felix Dakora demonstrated that in the the concentrations of potassium and iron can increase some nutrients in plants, it trace element uptake by cereal crops is our next research case of increasing trace elements in diets increased in only the leaves. decreases trace elements and therefore activity. Because soil bacteria (rhizobia) can increase in Africa, adding nitrates to crops would cannot be used to solve the problem. the concentrations of trace elements in nitrogen-fixing have the opposite intended effect. These increases in nutrients can be Taken together, this research provides a legumes, this means that a sustainable solution to the current practice of supplementing maize with trace explained; as the plant feeds on nitrates, very clear takeaway message; that there elements in South Africa can be found by identifying The study tested how several legume it also needs to take in potassium and is huge potential for legumes grown in effective soil that can promote increased plants (including cowpea) would respond calcium in order to restore ion balance. certain ways to decrease trace element absorption of these trace elements by maize and other to the addition of nitrates. The results While this may sound like good news, deficiency in rural Africa. cereal crops. That way, the greater concentrations of trace of his study showed that adding the study actually found that while elements in cereal grain will help to eliminate trace element nitrates to five different legume species nitrates can increase concentrations Although trace element deficiency is deficiency in Africa. More research also needs to be done to significantly altered the concentration of of some elements, nitrate supply a serious problem in many rural areas identify many different food plants that show high levels of significantly decreases the concentration in Africa, Professor Felix Dakora’s research trace elements in edible parts. Additionally, there is a need to understand how these trace elements are processed in of trace elements, thus decreasing the into both the potential of legumes the human body when consumed in food. Furthermore, dietary value of legume leaves. The study to contribute to lowering rates of trace we need a better understanding of how trace elements are further found that the concentrations of element deficiency and the effects reduced when nitrate is supplied to the plant. My ultimate trace elements including manganese, of adding nitrates to these plants is of aim is to completely eliminate trace element deficiency in zinc and boron decreased in four legume crucial importance. He has shown that rural Africa using food plants that have the ability to take up more trace elements from soils. yuda chen/Shutterstock.com species after nitrates had been applied. including legumes in agricultural systems The study also found that the addition is necessary for enhancing nutritional Nitrate fertilisers can significantly decrease the Photo shows a yellowish maize crop growing on an African soil that is poor concentration of trace elements, thus reducing of nitrates to legumes as they grow had security in Africa, and that nitrate use in nutrients, while the associated Bambara groundnut crop (a legume) is the dietary value of legume leaves. the potential to decrease the ability of is not necessarily part of this solution. looking green because it obtains its nitrogen mostly from air.

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