This is one of those biographies that provide a window onto the broader understanding of science in its social and cultural context. Using Sergei Nikolaevich Vinogradskii’s career and scientific research trajectory as a point of entry, this book illustrates the manner in which microbiologists, chemists, botanists, and plant physiologists inscribed the concept of a “cycle of life” into their investigations. Their research transformed a longstanding notion into the fundamental approaches and concepts that underlay the new ecological disciplines that emerged in the 1920s. The book presents a reconstruction of significant episodes of Vinogradskii’s laboratory practices and the role of theory in their development. It paints the broader picture of the history of ecology, microbiology and soil science and how these are uniquely united: through the concept of the cycle of life.