Sustainable management of organic agricultural wastes: contributions in nutrients availability, pollution mitigation and crop production

Recent climate variability, limited fertile land availability and soil degradation are major constraints to achieve food security for an ever-increasing human population. The adoption of intensive agriculture practices and highly productive agrosystems coupled with intensive use of agrochemicals has caused significant increases in agriculture production worldwide. This exhaustive production system has caused significant increases in generation and accumulation of large quantities organic wastes, which cause environmental pollution, deteriorate soil health and increase public health hazards. Conventional methods of organic waste management such as in situ burning of organic wastes, landfilling and chemical degradation are labour intensive, expensive and highly energy-consuming, and negatively impact the environment. Therefore, sustainable, eco-friendly and socially acceptable agri-technologies have been developed for value-added management of organic wastes and to obviate pollution problem. These biological technologies such as composting, anaerobic digestion, vermicomposting, production of biochar, organic phytostimulants, and bioremediation of pollutants have opened new vista for organic waste management. The addition of processed organic amendments (i.e., compost, vermicompost, biogas slurry and biochar) to the soil increases soil organic matter and nutrients availability, stimulates soil microbial community, contributes towards biocontrol of pathogens and also causes detoxification of pesticides. Furthermore, soil amendment with processed organic waste material, singly or with beneficial microbes, improved soil health, promoted growth of plants and increased the crop yields with less dependency on chemical fertilizers. In this article, the current technologies used for management of accumulated organic wastes are discussed for improving sustainable crop production, while maintaining environmental sustainability.