Selman Waksman, Humus: Origin, Composition, and Importance in Nature, 1938

Selman Waksman (1888-1973) extended Winogradsky’s influence in many ways: by adopting his research methods, participating in his expanding scientific network, assisting in publishing his 1949 collected works, and writing a laudatory biography of him. In Humus, Waksman applied Winogradsky’s methods and “cycle of life” perspective in his studies of humus (decaying organic material in the soil). For Waksman: The microorganisms influence the cycle of humus in nature in more than one way: 1. They bring about its formation from plant and animal residues. 2. They continuously transform humus and finally decompose it completely. 3. Their own cell substance contributes directly as a source of humus. The role of microorganisms in the cycle of organic matter in the soil, as well as in nature in general, is, therefore, indispensable.” (p. xiii)