Soil enzyme activities are of interest to soil scientists because they provide information on the ability of soils to perform biogeochemical reactions, they can be used as an index to detect impacts of anthropogenic management (agriculture and forestry) or pollution on soils, and they are generally simple, rapid, accurate, and inexpensive. The damage to soil fertility and depletion of plant nutrient elements in soil has emerged as major threats to the sustainability of diverse agricultural production systems. Therefore, soil enzymes activity study is considered an important tool to assess the nutrient transformation, nutrient availability and biological properties of soil to formulate crop and site specific nutrient recommendations vis-à-vis climate change strategies. A need, therefore, was felt to bring out a book on "Soil Dehydrogenase" that can helpful to the Soil Biochemists, Soil Biologist, Environmental Soil Specialists and Research Scholars of Soil Biology Laboratories andother Laboratory Technicians/Assistants working in the relevant field. The present book on "Soil Dehydrogenase" is an attempt in that direction.