Organic farming is being talked at various forum as a new approach and panaces for conservation of soil health and natural resources. Huge organic wastes being produced at crop fields, cattle yards, poultry farms, fish hatcheries, muncipal waste and garbage need to be properly utilized to save our environment, This compendium oresents basic concepts about the characterstics and composition of organic waste and its potentials for crop production. The chemistry and biochemistry of organic waste, its decomposition and mineralisation and manifestations on soil physical, chemical and microbial make up are highly specialized fields of study. Specialists in each of these topics have been invited to contribute and thus a comprehensive account on the biochemistry of organic residues, as source of plant nutrients, humification process and influence on soil fauna have been thoroughly dealt with. Hope the compendium will be very useful for those involved in maintaining soil health, natural resource conservation and organic farming movement. The book will also be equally beneficial for teachers and students of agricultural and environment sciences.