Dr Samson Chimphango

Research Interests

I am interested in understanding the physiological mechanisms of plant (especially legumes) adaptation to extreme edaphic conditions and climate change. Legumes are known to be high resource (nutrient) demanding for plant growth and biological nitrogen fixation. And yet, legumes are found in most of the ecosystems of the world including those with infertile and acid soils. The ability of legume species and their micro-symbiont to function under extreme conditions is quite amazing to me. Additionally, I also enjoy studying the influence of edaphic factors on the biogeography of legumes in an area.

Key Research Categories

• Legume adaptation to extreme edaphic factors and climate change
• Ecophysiology of legumes
• Legume biogeography –role of edaphic factors
• Phosphorus nutrition of indigenous legumes
• Economic use of legumes from natural systems
• Estimation of N2 derived from atmospheric fixation by symbiotic legumes in natural and agricultural ecosystems
• Enhancing biological N2 fixation in agricultural systems by exploiting legume genotypes and their microbial symbionts
• Minimisation of use of inorganic fertiliser in Agriculture by promoting soil microbial activity in:
• Biological nitrogen fixation
• Mycorrhizal effect
• Organic matter decomposition<>/li

Current Research Projects

The role and tolerance mechanisms of indigenous N2 fixing legumes in the acidic and low P environment of the Western Cape Floristic Region, South Africa. (Funded by the NRF, South Africa).

The role of edaphic factors in the biogeography of legumes in the Cape Floristic Region

Rhizobia diversity in the Cape Floristic Region

Improving soil fertility and water retention by using low C:N organic residues in rooibos tea cultivation at Nieuwoudtville, Northern Cape, South Africa.

Student Supervision

1. Mark Maistry (Supervisor) MSc project titled “An investigation of phosphorous constraints on biological nitrogen fixation (BNF) in indigenous legumes adapted to the infertile soils of the Cape Floristic Region” (Graduated June 2010)
• Mr Maistry is continuing with his studies for a PhD Degree on a project titled “Enhanced P acquisition strategies and symbiotic N2-fixation in low P adapted Aspalathus and Podalyria species indigenous to the Cape Floristic Region”.
2. Simon Power (Supervisor) MSc project titled “Do ecophysiological traits of legumes account for their lack of persistence in late-successional post-fire CFR?” (Graduated, December 2010)
3. Meshack Dludlu (Co-supervisor): MSc project titled “Systematics of the genus Otholobium C.H. Stirton (Leguminosae)”. (Graduated, December 2010)
4. Joachim Makoi (Co-supervisor): PhD project titled “Assessing flavonoid concentration in cowpea genotypes and the effect of plant density on growth, N2-fixation and rhizosphere phosphatases and grain yield of cowpea intercropped with sorghum” Cape Peninsula University of Technology (Graduated, March 2010).
5. Gardia Potgieter (Supervisor) MSc project titled “N and P limitation of legumes and non-legume plants of the Cape Floristic Region, South Africa. (Ongoing)
6. Oscar Dlodlo (Supervisor): MSc project titled “Characterization of rhizobia isolated from nodules of indigenous legumes and their effect on host plant distribution in the Cape Floristic Region, South Africa. (Ongoing)
7. Aluwani Tshiila (Co-supervisor): MSc project titled “Systematic studies of the Ficinia Clade (Cyperaceae) (Ongoing)
8. Stefan Milandri (Co-supervisor): MSc project titled “An investigation into the ability of vegetated biofilters to treat stormwater in the City of Cape Town, South Africa. (Ongoing)
9. Rabelani Munyai (Co-supervisor): MSc project titled “Are old monotypic Cape lineages genetically abd ecologically impoverished? A case study of Prionium. (Ongoing)

Publication - Peer reviewed

1. Makoi JHJR, Chimphango SBM, Dakora FD. 2010. Photosynthesis, water-use efficiency and δ13C of five cowpea genotpyes groan in mixed culture and at different densities with sorghum. Photosynthetica 48, 143-155
2. Makoi JHJR, Chimphango SBM, Dakora FD. 2010. Elevated levels of acid and alkaline phosphatase activity in roots and rhizosphere of cowpea  (Vigna unguiculata L. Walp) genotypes grown in mixed culture and at different densities with sorghum (Sorghum bicolour L. Moench). Crops and Pasture Science 61, 279-286.
3. Power SC, Cramer MD, Verboom GA, Chimphango SBM. 2010. Does phosphate acquisition constrain legume persistence in the fynbos of the Cape Floristic Region? Plant and Soil, 224, 33-46.
4. Makoi JHJR, Chimphango SBM, Dakora FD. 2010. Seed flavonoids and anthocyanins as markers of enhanced plant defence in nodulated cowpea  (Vigna unguiculata L. Walp). Field Crops Research, 118, 21-27.
5. Makoi JHJR, Chimphango SBM, Dakora FD. 2009. Effect of legume plant density and mixed culture on symbiotic N2 fixation in five cowpea genotypes in South Africa. Symbiosis 48, 57-67.
6. Naab JB, Chimphango SBM, Dakora FD. 2009. N2 fixation in cowpea plants grown in farmers’ fields in the Upper West Region of Ghana, measured using 15N natural abundance. Symbiosis 48, 37-46.
7. Dakora FD, Chimphango SBM, Valentine AJ, Wlmerich C, Newton WE (Eds.). 2008. Biological Nitrogen Fixation: Towards Poverty Alleviation through Sustainable Agriculture. Proceedings of the 15th International Nitrogen Fixation Congress and the 12th International Conference of the African Association for Biological Nitrogen Fixation, 21-26 January 2007, Cape town, South Africa. Current Plant Sciences and Biotechnology in Agriculture, Vol. 42. Springer, New York, USA.
8. Chimphango SBM , Brown CF, Musil CF and Dakora FD. 2007. Effects of elevated UV-B radiation on seed yield of Glycine max and an assessment of F1 generation for carryover effects. Physilogia Plantarum 131, 378-386.
9. Cramer MD, Chimphango SMB, van Cauter A, Waldram Matt, Bond WJ. 2007. Grass competition induces N2 fixation in some species of African Acacia. Journal of Ecology 95, 1123-1133.
10. Chimphango SBM , Musil CF and Dakora FD (2004) Response to ultraviolet-B radiation by purely symbiotic and NO 3-fed nodulated tree and shrub legumes indigenous to Southern Africa. Tree Physiology24, 181-192.
11. Chimphango SBM , Musil CF and Dakora FD (2004) Impact of increased ultraviolet-B radiation stress due to stratospheric ozone depletion on N 2 fixation in traditional African commercial legumes. South African Journal of Botany70, 790-796.
12. Chimphango SBM , Musil CF and Dakora FD (2003) Effect of ultraviolet-B radiation on plant growth, symbiotic function and concentration of metabolites in three tropical legumes. Functional Plant Biology30, 309-318
13. Chimphango SBM , Musil CF and Dakora FD (2003) Response of purely symbiotic and NO 3-fed nodulated plants of lupinus luteus and vicia atropurpurea to ultraviolet-B radiation. Journal of Experimental Botany54, 1771-1784.
14. Musil CF, Kgope BS, Chimphango SBM and Dakora FD (2003) Nitrate additions enhance the photosynthetic sensitivity of a nodulated South African Mediterranean-climate legume ( Podalyria calyptrata) to elevated UV-B. Environmental and Experimental Botany50, 197-210.
15. Musil CF, Chimphango SBM and Dakora FD (2002) Effects of elevated Ultraviolet-B radiation on native and cultivated plants of Southern Africa. Annals of Botany 90, 127-137.