In memoriam - Anthony Roger (Tony) Dexter (1942 – 2021)
Anthony Roger (Tony) Dexter was born on 30 December 1942 in Bedford in the heart of England. Tony attended Bedford Modern School. For those not familiar with English schools “Modern” here refers to a separation from Bedford School in the mid-1700’s! Tony completed his BSc in physics (electronics) at City University, London in 1965 before being awarded a PhD in physical chemistry at the University of Essex in 1970 for a thesis titled “The high-frequency mechanical response of super-cooled liquids”. At the end of 1969 Tony married Caroline and they moved to Scotland where he continued his research on mechanical properties of super-cooled viscous liquids as a post-doctoral fellow at the Bio-Engineering Unit at Strathclyde University. Tony was appointed to the National Institute of Agricultural Engineering, Silsoe in his native Bedfordshire in late 1971.
In 1973 Tony and Caroline emigrated to Adelaide where Tony had accepted the post of lecturer in soil physics following the premature death of Keith (KP) Barley. This appointment was in the Department of Agricultural Chemistry and Soil Science of the University of Adelaide – with Soil Science becoming a separate department soon after. The Department was based at the Waite campus about 7 km from the main university campus where there was sufficient land for agricultural experiments. Tony and Caroline established themselves in the small town of Mt Barker about 20 km away. Sons Tom and David arrived. Tony had an old VW beetle that he used for the commute. We’re not sure exactly when Tony joined ISTRO but certainly he attended the 8th conference in Hohenheim in 1979. This was a scientifically productive time for Tony. He generated substantial external funding from the cereal and oilseed industries, and this supported his work on plant roots. The funding and the prodigious scientific output saw Tony rapidly promoted to Senior Lecturer then Reader/Associate Professor. It was during this time that the seminal work on soil friability began. He supervised a succession of PhD students, hosted several international visitors, and took advantage of sabbaticals to collaborate with people in the Netherlands (B. Kroesbergen), Germany (Rainer Horn), Sweden (Inge Håkansson), Canada (Bev Kay) and the USA (Jerry Radke). His grants employed post-doctoral scientists including John Hewitt and Bent Jakobsen. Although the faculty of Agriculture in which he was based had no provision for awarding higher doctorates, Tony’s work on plant roots was acknowledged through the Department of Botany at the University of Adelaide with the award of a DSc in 1988.
In August 1990 Tony returned to Silsoe to head a group on soil physics. He worked closely with Chris Watts, Richard Whalley and others to set up labs with constant temperature rooms, loading frames, penetrometers and soil-water retention equipment. The work of the group focused on the environmental impact of mechanized agriculture on soil function and the wider environment. The study of processes controlling soil function is highly complex, requiring a multi-disciplinary approach, so many links were formed with scientists not only in the UK but throughout Europe and beyond. As with all Tony’s work the golden thread running throughout was soil structure, its form, stability and resilience. Under Tony’s guidance the group grew and included Richard Whalley and Lawrence Clark working on plant root, Nigel Bird working on fractals fluid movement, and Chris Watts and Andy Gregory working on friability and resilience. Postgraduate students supervised by Tony were registered with universities in the UK and elsewhere in Europe. He was made a Visiting Professor by Cranfield University during this time.
In keeping with his choice of non-standard cars, Tony has his much loved “Dolly” model 2CV car at this time. His Francophile credentials were clear in the choice of a modern Citroen as the family car, but it was his much-loved red and white “Dolly” model 2CV that was his real joy. His aversion to strenuous physical exercise was evidenced by his often driving “Dolly” for the 100 m from his office to the lunch canteen. Tony and Caroline separated in the mid 1990’s but Tony continued to support Tom and David through post-secondary education and into employment.
Tony met soil scientist Ewa Czyż and took a sabbatical to the Institute of Soil Science and Plant Cultivation (IUNG) in Puławy, Poland. This started a collaboration between his group at Silsoe, UK and IUNG, Puławy, Poland. At this time there was a compulsory retirement age of 60 at UK research institutes. Tony was clear that he was not ready to retire at 60 and wanted to continue his research.
In 1997 Tony moved to the post of Professor at IUNG leading the Soil Physics Group in the Department of Soil Science, Erosion and Land Protection Puławy, Poland. He continued his research, working closely with Ewa and they collaborated widely on soil and plant-water management, soil physics and environmental protection. The result of his research and international collaboration over the period 1997-2004 was a series of three publications (in 2004), the result of which was the development of a universal indicator of the physical quality of soil, “S”. This work was the basis for the Director’s award at IUNG for 2004. In 2004 Tony spent time at the University of Sao Paolo, Brazil working with Alvaro Da Silva and colleagues and in 2008 he spent a year at INRA, Orleans, France collaborating with Guy Richard and others. Tony was appointed a full professor by President Lech Kaczyński in October 2007. He retired in 2012 although he continued to publish until at least 2019.
In retirement Tony divided his time between Ewa and Poland and a house in Brightlingsea on the Essex coast. He was a keen sailor and skilled mariner and taught sailing to disadvantaged young people. He was also a keen radio ham. He was widely read and always good company. He was in Brightlingsea when the Covid pandemic hit and was unable to return to Poland. For the last 18 months of his life Tony remained in Brightlingsea but kept regular contact with Ewa by Zoom. Following a fall, he was admitted to Colchester hospital where he passed in mid-October.
Tony’s scientific legacy is outstanding. He published more than 250 papers in refereed international scientific journals and at the time of writing has a Hirsch index of H = 50. His writing style was clear and succinct and he had an ability to simplify science to enable understanding. Tony took teaching responsibilities seriously and always seemed to have time to interact with students and young researchers. The list may not be complete, but he was a key supervisor to the following PhD students Stephen Ojeniyi, Mike Braunack, Wani Utomo, Geoff Whitely, Rabi Misra, Blair McKenzie, Cameron Grant, Simeon Materechera, Paul Hallett, Andrew Brown, Chris Watts, Sonia Czarnes, and Thomas Keller. Tony’s research covered a range of topics that he grouped into topic areas including the physics of soil/plant-root interactions; research on the physics of soil biology interactions (including earthworms and microbes); research on soil structure; soil hydraulic properties and soil physical quality. He had deep understanding of the physical, chemical and biological principals controlling soil function and used this understanding to explain soil behaviour. Those of us lucky enough to have worked with Tony will certainly miss him as a friend, but his many published papers will be a lasting memorial to a great scientist.
By Blair McKenzie, Chris Watts and Ewa Czyż (with help from Caroline, Tom and David Dexter).