IN MEMORIAM – Louis Dekker (1939 – 2019)

Louis Dekker – a figurehead in soil science is no longer among us

Louis Dekker - © Bonny DekkerDr Louis Dekker, former ESG staff member, died after a short illness on 20 November 2019, at the age of 80. Louis worked in Wageningen with Stiboka, the DLO Winand Staring Centrum and then Alterra for a total of 47.5 years. Following his retirement in 2004, Louis remained with Alterra as a guest staff member and then, in 2012, transferred to the Soil Physics and Land Management chair group at Wageningen University and Research. Louis was active in the scientific field right through to the end of his life – a total of 63 years, undoubtedly a record for Wageningen. Working with Louis was nothing less than a privilege, as he possessed a number of unique personal qualities that were ideally suited to research and were a source of inspiration to others to join in.

His many years’ experience in soil mapping activities during the period between 1956 and the mid-70s made Louis a walking encyclopaedia of Dutch soil science and a source of knowledge for many of his colleagues who had specific questions. Louis was extremely enthusiastic about soil mapping and had an eye for strange patterns in the landscape and in the soil: he was fascinated by them and wanted to understand how they were formed. When soil mapping went on the back-burner after the completion of a map series in the 70s, Louis gained more and more time to focus on in-depth research.

Louis demonstrated that he was also an enthusiastic scientist and a born problem-solver who based his research on a wealth of field observations, measurements and analyses. During this period, Louis worked for many years with colleagues including Johan Bouma, Jan Hendrickx, Klaas Oostindie, Jan Wesseling, Tammo Steenhuis, John Nieber, Coen Ritsema and many others. Many colleagues remember Louis for his cartloads of soil samples that arrived at our building at the end of long days in the field, totally unknown in those days and something no one understood. However, these tremendous quantities of samples – often collected from a single field or small plot – yielded many new insights into soil science, such as water currents in shrinking and swelling clay soils and the behaviour of water repellent soils, an area in soil science in which Louis acquired world fame.

The results from his research drew attention from abroad, which in turn resulted in his increasing number of international trips to a wide range of congresses, project meetings and locations for field research in countries including the USA, Mexico, Australia, New Zealand, Thailand, Russia and many European countries. Louis often combined business with leisure during his travels, which he always found a source of inspiration for new research that he planned and carried out on his return. While he was enjoying a couple of beers on a terrace in New Zealand, Louis also came up with the idea of graduating with his PhD on the same day as Coen Ritsema, under supervision of Prof. Johan Bouma and Prof. Reinder Feddes. Louis actually graduated some time afterwards, in 1998 – an unforgettable event for Louis, his family and his friends.

Louis was also an extremely gifted writer: he wrote more than 250 articles and reports, no fewer than 75 of which after his retirement! Louis wanted to make his knowledge accessible to as broad a public as possible, which he did by writing articles that were published in almost 45 scientific journals. His articles also had effect: many colleagues cited some 10000 references to his work, evidence of the great influence his research has had on other scientists. His influence is actually so great that scientists all over the world still refer to his work almost every day and are expected to continue to do so during the coming decades. This is also exactly in line with what Louis often said – ‘Writers are immortal’ (in Dutch: Wie schrijft, die blijft).

Louis also held hundreds of presentations for farmers, horticulturists, nature organisations, golf course managers, students, scientists and policymakers. His clear texts, illustrated with terrific photos from his field research, were appreciated by everyone who attended one of his presentations.

All-in-all, Louis was a unique man, an enthusiastic and successful scientist, an inspiring and humorous colleague – and a leading figurehead in soil science. We will miss his knowledge, readiness to help and humour, not only as a colleague but also as a friend.

Messages to Louis's family can be sent by post to Vera Dekker (Nieuwe Veenendaalseweg 220 C, 3911 MS Rhenen, the Netherlands), or by email to .

By Coen Ritsema, on behalf of the Soil Physics and Land Management group, Wageningen University, the Netherlands


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Page created: 19.12.2019 | Page updated: 19.12.2019

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