Microbial Conversion of Agricultural Residues into Organic Fertilizers

Presently in developing countries, solid waste management is one of the crucial challenges since the need to use eco-friendly techniques appropriately increases alarmingly. Technological development, intensification, and urbanization of smart agriculture procedures have drastically accelerated waste generation from post-agricultural processes in recent years. Of course, the awareness of current technological implementation and the look for sustainability has provided a huge research platform for reducing unnecessary waste. From this context, the approaches, recycling, and microbial biotransformation are being applied to produce different valuable organic substances, such as high-quality bio-fertilizers. However, microbial approaches receive well appreciations due to their eco-friendliness. Besides, they can produce organic fertilizers that could significantly mitigate the impact of toxic chemical fertilizers. Consequently, microbial transformations are identified to recover macro- (N, P, and K) and micronutrients (Mg, Ca, Fe, Na, Mn, Cu, B, Zn, S, and Mo) and other value-added products. However, the fertilizers’ characteristics may differ depending on the waste types. From this perspective, the chapter provides a comprehensive insight into agricultural waste management to produce organic fertilizers. Additionally, the trends, challenges, and prospects related to microbial methods of transformations are explored to consider the future development of sustainability perspectives.