Organic fertilizer refers to materials used as fertilizer that occur regularly in nature, usually as a by product or end product of a naturally occurring process. Organic fertilizers such as manure have been used in agriculture for thousands of years; ancient farmers did not understand the chemistry involved, but they did recognize the benefit of providing their crops with organic material. Interest in organic farming is growing worldwide as sustainable agricultural practice nowadays. Organic fertilizers are sustained sources of nutrients due to slow release during decomposition. By increasing soil organic matter, organic farming can reinstate the natural fertility of the damaged soil, which will improve the crop productivity to feed the growing population. Organic fertilizers enhance the natural soil processes, which have long-term effects on soil fertility. The book is a very valuable compilation in this direction.