Gedroits, Konstantin Kaetanovich

Born Mar. 25 (Apr. 6), 1872, in Bendery, present-day Moldavian SSR; died Oct. 5, 1932, in Moscow. Soviet soil scientist and agricultural chemist; academician of the Academy of Sciences of the USSR (1929). Born into the family of an army physician. Graduated from the St. Petersburg Institute of Forestry in 1898 and from the natural-science division of the department of physics and mathematics of the University of St. Petersburg in 1903. From 1918 to 1928 he was on the staff of the Soils Institute of the Academy of Sciences of the USSR; he was its director from 1928 to 1930. He was a professor at the Institute of Forestry in Petrograd (Leningrad) from 1918 to 1930. He was elected president of the International Association of Soil Scientists in 1927.

Gedroits’ work in the field of colloid chemistry of soils is particularly important. He discovered in soils an “absorbing” (colloidal) complex consisting of minerals and very fine organic-mineral and organic particles. The so-called exchange cations that are found on the surface of these particles and that can be exchanged for the cations of salt solutions characterize the physical and chemical properties of the soil and influence the dynamics of the soil processes. Treating the soil as a three-phase, dynamic physicochemical system, Gedroits shed new light on the genesis of soils and on the nature of many of their important properties. He developed the principles for a new soil classification based on their exchange cations. He discovered the nature of soil alkalinity, developed the teaching on the origin of solonetses and solods, and created a theory of their reclamation. He was awarded the Lenin Prize in 1927.