The pursuit of knowledge truly is a lifelong endeavour – as demonstrated by 80-year-old Meiring du Plessis, who recently graduated with a PhD in Soil Science during the University of Pretoria’s (UP) autumn graduation season.

“Receiving a PhD in the month I turn 80 is a special gift from my heavenly Father,” he says. “I am blessed with good health and I am still compos mentis.”

Next to the guidance, advice and encouragement provided by his supervisor, Prof. John Annandale, Du Plessis credits his wife, Miemie, for being his main source of support.

“She was the first person I told about each examiner report that came in,” he says. “She encouraged me from the start, and never wavered in her support. She also took responsibility for so many chores that were my responsibility. Next to learn about my pass were our children, who were always supportive and encouraging, while being discreet in their enquiries about the (slow) progress their dad was making.”

His thesis is about risk-based, site-specific irrigation water quality guidelines. Du Plessis envisages that his research will find universal acceptance and application among irrigation users.

“It describes the development and main features of a newly developed software-based decision support system with which to assess the fitness for use of water containing several non-traditional water constituents for irrigation,” he explains. “The support system uses mainly internationally accepted cause-and-effect relationships to assess the effect of water quality constituents.”

Du Plessis admits that he was anxious about the nature of his research and how it would be received.

“I’m sure all students experience a stressful period while waiting for the results of their reports,” he says. “For me, it was especially stressful because my thesis did not represent a typical PhD thesis that presents a collection of research regarding a particular topic and related hypotheses. Rather, mine presented a decision-support tool. So you can understand how ecstatic I was when the examiner reports returned with a positive verdict and were quite complimentary. In fact, one examiner remarked: ‘To my knowledge, the decision support system is a first in the world and therefore novel.’”

Du Plessis was born in Gqeberha, and at the age at of nine, his family moved to Tshwane. He began his career in 1965 as an assistant professional officer at the Soil and Irrigation Research Institute of the then Department of Agricultural Technical Services, before becoming the deputy director responsible for soil surveys and irrigation planning. In 1987, he joined the Water Research Commission as a research manager, a position he retired from in 2009.

“When we think about education, our first thought is about acquiring knowledge that will equip us for a successful career in our favoured field of interest,” he says. “But education is more than that – attending a university helps you to grow into a well-balanced person who is inquisitive and open to new ideas, yet able to evaluate them critically. You also learn to be more tolerant of others who do not think similarly to you.”

He adds that university is a place where you meet people you would not otherwise meet, and make friends with like-minded people.

“It is where you start to develop your network of people on whom you can call for the rest of your life,” Du Plessis says. “I am reminded of something a professor once shared with me –education is that which you remember once you have forgotten everything you have been taught in class at varsity.”

He fondly notes how eager the next generation at UP is to acquire knowledge and make a success of their studies.

“It gives me great satisfaction when some of them tell me that my example inspired them to do the same.”