Jan Henri Druif and the Soils of Deli.
The profile of Jan Henri Druif (1893–1970), the pioneer of the discovery of the Soils of Deli.
Jan Henri Druif was a Dutch soil scientist (pedologist) known for his work on the mapping of soils in Deli, Sumatra. Druif was born in 1893, in Rotterdam. His education includes the Wageningen Agricultural College, the Technical College at Delft, Utrecht University (PhD), and Hanover Technical College (Germany).
He graduated his PhD in 1927 at Utrecht University under Prof. L.M.R. Rutten’s supervision with a dissertation titled: Over het ontstaan der Limburgsche löss in verband met haar mineralogische samenstelling. His dissertation is on the mineralogical investigation of the origin of Limburg loess in the south of Holland. He investigated the composition and origin of the deposit. The thesis showed his expertise in mineral petrography in explaining the origin of soils.
He got a job as an agrogeologist at the Deli research station in Medan and started work there on 15th August 1929. He was assigned to map the soils of Deli after many unsuccessful previous attempts by chemists. The chemists had tried to map the soils of Deli since 1897 but still could not produce a decent soil map that shows where the good soils are.
The soils in Deli all looked almost the same, some red ones, some grey, and a few black ones. Yet, the quality and price of tobacco produced by two seemingly same red soils were completely different. The price of tobacco could vary from NLG 18 to NLG 2.50 per pound, depending on the soil on which it was grown.
It was not until 1915 that the researchers of Deli realized that the area’s geology had a strong influence on the soil. Druif continued his predecessor’s work and made lots of field observations of outcrops, transects, hand augers across Deli. He made numerous laboratory mineralogical observations of the rocks and soils.
Finally, Druif made a breakthrough by recognising the distribution of different rocks in which the soils formed. The soils of Deli had been affected by several volcano eruptions, the largest being the Toba super-eruption 74,000 years ago. However soils derived from that eruption are quite acid and not fertile. Subsequent eruptions of ashes and lahars from Sinabung and Sibayak mountains produced much better fertile soils that are suitable for tobacco.
Subsequently, he made detailed soil descriptions of Deli in his publication: De Bodem van Deli or The Soils of Deli.
The first series of De Bodem van Deli was published in 1932 under the bulletin of the Deli research station №32, outlining the geology of the area. This was followed by part II: on the mineral of the soils of Deli in 1934. This seminal work highlighted the use of the mineralogical approach for soil classification. In 1938, he published the final series of De Bodem van Deli from Bogor as a compilation of all results.
In 1935, Druif completed a 1:100,000 agrogeological (soil) map of the Deli area based on a geological-morphological-mineralogical approach. The soils were grouped based on the materials where they were formed. This was quite a significant work, as soil mapping had just begun in Europe and USA.
Jan married Anna Maria Hubertina Ceulemans (1896–1950) in 1924. They had 3 children. The Druif was a well-known family in Medan’s social life. A devout Catholic, Druif was an avid football player. He was a well-known referee, a member of the Dutch East Indies Football Union consul, and Chairman of the OSVB football club in Medan. He wrote three books on football and its rules. He was also a fire brigade volunteer. He lived at Manggalaan Straat №45 in Medan, near the Deli Proefstation.
He also gave lectures on various topics for the learned community in Medan, such as Medan as the epicentre of earthquake.
The 1931 global financial crisis caused a poor sale of tobacco, he was made redundant in early May 1932. Several newspapers reported how his dismissal was a great loss to Deli, and Druif was hired back a week later.
In 1935, on his holiday back to the Netherlands, he gave a lecture to the Leiden Geology and Biology Club on the great influence of soil on tobacco quality.
He completed his contract at the Deli research station in 1938, and he was much missed for his contribution as the chairman of the East Coast of Sumatra Football Association (OSVB).
Druif soon was appointed as a pedologist at the Soil Science Institute at Buitenzorg (Bogor) in 1939. The immediate work was to map soils in Palembang for rubber plantations.
But the Japanese arrived, and he was interned in a camp near Bogor.
In 1946, he was transferred to the Makassar (SW. Celebes) branch of the General Experiment Station and married Johanna Catharina van der Mull (born in 1910 in Ternate, Molukken, died 2003 in Zutphen, Gelderland).
He conducted several soil surveys in the eastern part of Indonesia, including a survey in Timor, and West Papua in 1941 and 1953.
He left Indonesia in 1958. Afterward, he moved to Suriname. He died in Suriname on 11th February 1970. He was teaching at the De Stichting De Vrije School at the time.
Not much else was known about him, except that his work on the soils of Deli had been frequently referenced as one of the outstanding soil works in the Netherlands East Indies.
Druif’s writing showed that he is critical and detailed. While his cartography is not the best, De Bodem van Deli contributed to the understanding of North Sumatra’s soil and geology.
