School of Agricultural, Earth and Environmental Sciences

A proud Mr Thando Mthembu.

Passion for Research Stirred in Master’s Graduate

Mr Thando Mthembu’s research on the water productivity of an indigenous crop helped him find a “sweet spot” for exploring academia and research and a line of work that is shaping his career trajectory.

Raised in Pietermaritzburg, Mthembu attended Scottsville Primary School and Alexandra High School, where his favourite subjects were Science and Geography.

With an awareness of climate change issues, Mthembu sought to find a vocation where he could contribute to combating the effects of this phenomenon. UKZN’s strength in its hydrological and agriculture programmes thus made the Institution his first choice.

He enrolled for an undergraduate degree in Hydrology and Soil Science and did his Honours in Hydrology, supervised by Mr Richard Kunz. This work exposed him to the concept of the Water-Energy-Food (WEF) nexus, an area where Mthembu found he could marry the disciplines of hydrology and agriculture, and that working in research and academia was a comfortable fit for him.

He decided to continue his work to master’s level, enrolling for a study funded under a Water Research Commission (WRC) project on the water use of indigenous root and tuber food crops.

Mthembu’s project involved assessing the water productivity of sweet potatoes, an important study for determining the water use of crops that have the potential to be high yielding in a water-efficient manner, which organisations including the WRC are promoting for cultivation in water-scarce environments such as South Africa. Crops like this also have promise for biofuel production as their sugars and starch can be converted into bioethanol.

‘The rural poor are particularly affected by climate change and crops like this are high-yielding, nutrient-dense and water-efficient,’ said Mthembu.

His research trial was situated at the Fountainhill Estate near Wartburg where field research did not come without its challenges, as he faced concerns about his crops receiving sufficient rainfall to grow optimally since he used no supplemental irrigation, and was concerned about the effects of hailstones from severe storms. These weather conditions did not adversely affect his work, but toward the end of the season, his trial was hit by porcupines which ate some of the sweet potatoes. He was able to harvest enough to derive the necessary data, however, and while finding the equipment to freeze dry his samples was also a challenge, he succeeded thanks to the collaboration of the project team and his supervisors.

Mthembu was able to develop a new dataset that contributes to the knowledge base on nutrient content, water use, water productivity, yield and management practices for sweet potato production in dryland conditions. He found that yield was higher than some studies in the literature that received irrigation as well as rainfall, however, he highlighted the importance of delineating the regions where these high-yielding crops were thriving with no irrigation. While the crop is drought-tolerant, prolonged dry conditions will affect its yield.

Mthembu presented his research at the South African Hydrological Society conference last year, and in December also received second prize in the School of Agricultural, Earth and Environmental Sciences for his oral presentation at UKZN’s Postgraduate Research and Innovation Symposium.

Mthembu, who tutored and demonstrated to students during his studies and sees himself in an academic career, is now doing a PhD on developing and applying a crop database for underutilised crops in South Africa, also funded by the WRC.

He thanked his family and supervisors, Kunz and Professor Tafadzwa Mabhaudhi, for their support during his studies as well as the WRC and the National Research Foundation for funding his studies.

Words: Christine Cuénod

Photograph: Abhi Indrarajan