Update: 27.05.2018

In a handful of fertile soil, there are more individual organisms than the total number of human beings that have ever existed.

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The International Union of Soil Sciences (IUSS) is the global union of soil scientists. The objectives of the IUSS are to promote all branches of soil science, and to support all soil scientists across the world in the pursuit of their activities. This website provides information for IUSS members and those interested in soil science.

in memoriam - Jan de Geus (1908-2003)

Jan de Geus (1908-2003)

Ir Jan (Gijsbert) de Geus, who died on 10th June at the age of 95, had played an important role in the world of tropical agriculture, initially in Indonesia, but later throughout the tropics.

Jan was born on a farm in Bruchem in the river clay area in the central part of the Netherlands. He started his studies in Wageningen at the Agricultural University in 1928 and thoroughly enjoyed student life. He was lectured by Prof. J. van Baren and after 1933, by Prof. C.H. Edelman. Jan graduated in 1936 with a major in tropical plant science. In 1937 he was employed by a Dutch fertiliser company and sent to Dutch East Indies (Indonesia) where he became responsible for advising plantation companies on their inorganic fertiliser strategies. During this time he developed a strong interest in soil-plant relationships and the development of the plantation industry in West Java and other parts. Jan wrote many articles for the journal ‘De Bergcultures’ on a variety of subjects and following the advice of Prof. Edelman he published a booklet on the Mountainous soils of West Java (Bergcultuurgronden op Java).

The booklet was widely used for soil science courses to young planters. The focus of the book was on soil properties in relation to plantation crops (rubber, cocoa etc) and inorganic fertilisers. In the late 1930s little inorganic fertilisers were used which was related to the economic recession, the availability, as well as lack of knowledge on its effects. It was Jan’s task to increase that use. In those years he felt, as he mentioned later in life, very much between a soil scientist and a planter.

During the war he spent some years in Japanese imprison camps and he was sent home to the Netherlands when the war had ended in 1945. He quickly recovered and went back to Indonesia when the first opportunity arose. Much had changed as compared to the period before the war and Jan was besides agronomic work also put in charge of commercial activities. ‘It is not what I wanted’ he mentioned later ‘but I had no choice and after all I learned much from it’. When the political situation in Indonesia changed Jan, returned to the Central office in The Hague where his working field was enlarged. Now he was in charge of the entire world and his first travels brought him to China and other Southeast Asian countries. The travelling fostered his interest for rice and resulted in the book ‘Means of increasing rice production’ in 1954. In the decades that followed Jan travelled the entire tropical world and for most of the year he was on the road. His main duties were to encourage and sell inorganic fertilisers and he had the sensible combination of a practical scientist and some sort of a salesman. He also collected an enormous amount of information on fertiliser use and crop production.

That information was used for his magnum opus: ‘Fertilizer guide for the tropics and subtropics’. A 774-pages work that contains detailed information on fertiliser requirements of nearly all tropical crops. The work was based on Jan’s collection of information from the research stations and contains more than 5000 references. The first edition was finished when he retired in 1967 and the second much larger edition, was finished in 1972. There is no recent book with so much detailed information about inorganic fertilisers and in many cases the ‘Guide’ is still useful. It is also a very readable book. When I was soil surveying a remote oilpalm plantation in Tanzania in the late 1980s and had finished all my other literature, I started reading it and enjoyed it from cover to cover. I found hardly any errors and also much enjoyed the printing quality and pictures (compare this to any new soil science book and you see what I mean).

Jan’s official retirement meant that he travelled less and more frequently visited scientific meetings in Wageningen and Amsterdam. He had an encyclopaedic knowledge on tropical agriculture which meant that he would sometimes interrupt an exciting young speaker talking about his research. Jan would mention that it had already been researched in the 1930s and if the speaker was interested he would send him the papers. He made a major contribution to a soil bibliography on Indonesia and Jan was also a weekly visitor at the Royal Tropical Institute (KIT) in Amsterdam where he browsed the library to keep him informed about developments in areas of interest. It was in the 1960s he mentioned some years back when we had lunch at KIT, that you would come across Prof. Mohr on the stairs and that you were not allowed to greet him as he would loose his concentration and fall. I am now in that position, he ended with laughter. Old age brought him discomfort but he kept interest and read the Wageningen University newsletters as well as the IUSS Bulletins.

There are many stories about Jan. Some years after he had started his studies he had a severe motor-accident. His leg was badly fractured and according to the surgeon in hospital it had to be surgically removed. ‘Never’ he replied after which the surgeon said ‘But then you die’. This was in the early 1930s and antibiotics had yet to be discovered. Jan refused to have his leg removed as he knew it would make him unsuitable for work in the Dutch East Indies. Jan has enjoyed all of his long-life but he frequently mentioned that his first period in Indonesia was his best.

He was a remarkable and very pleasant man with an enormous interest in world affairs until late age. With him Wageningen lost one of his early graduates. With him also the first generation died who advocated judicious fertiliser use in the tropics. Given the urgent need to increase food production to mitigate world hunger, inorganic fertilisers remain indispensable. Jan de Geus said that his entire life.

Alfred Hartemink

Wageningen