Organic Waste in Agriculture

Largely accessible organic wastes can be turned into valuable compost product for raising crops organically on one hand, and get them disposed of safely at the other end. Straight use of organic wastes has tribulations like transportation and handling, wider C:N ratio, high application rates, nutrient overloading, weed seeds, pathogens, and metal toxicities. Inadequate organic waste management leads to a plethora of problems such as environmental pollution, eutrophication, and esthetic damage to urban landscape, greenhouse gases emission and effects on human health. Unwise and non-scientific disposal of wastes not only poses a grave threat to environmental quality but also results in loss of economic value of wastes. Since organic wastes are an abundant pool of organic matter and valuable plant nutrients, agricultural recycling of these wastes appears to be a promising alternative enabling value addition and their resourceful utilization. Land application of organic wastes stabilized through techniques such as composting, vermicomposting and anaerobic digestion yielding excellent organic fertilizer like compost augments soil fertility and crop yield. The objective of utilizing organic wastes in agriculture is to maintain a sustainability cycle where waste s biodegradable organic fraction is converted into useful organic manure or fertilizer through methods like composting, vermicomposting and anaerobic digestion to produce compost and slurry for agricultural use.

The agricultural uses of municipal and industrial wastes a re regulated to protect human health and the environment. Source-separated materials may be eligible for end-of-waste status if they meet recognized quality criteria, in which case they become fully recovered products. In some jurisdictions, however, treated residuals derived from mixed waste streams, such as compost or digestives from mechanically segregated biodegradable municipal solid waste, may be considered unsuitable for end-of-waste status or for agricultural use altogether due to quality concerns, despite them potentially achieving relatively similar standards. Without a sound scientific rationale, policy development to agricultural recycling becomes confused and illogical, restricting the opportunities for beneficial use. Understanding the fundamental agronomic properties of different types of organic waste materials applied to land is essential for the development of appropriate fertilizer guidance and best management practices.

The survival of infectious microorganisms, the consequences for the food chain and the environment of the long-term accumulation of potential toxic elements in soil and of organic contaminants in organic residuals, and potential odor emissions, are further important challenges to agricultural recycling. However, these can also be managed and addressed by sound scientific understanding.

The book covers different aspect of agricultural recycling of organic wastes, including, for example, fertilizer use efficiency, nutrient transformations and transport, denitrification, best management practices, effects on soil physical properties, crop production and quality, and potentially toxic elements. However, effective utilization of organic wastes for agricultural purposes requires thorough and strict risk assessment to prevent the adverse effects of contaminants like heavy metals, persistent organic pollutants to ensure agro-environmental sustainability. The present book aims to enlist the positives and negatives associated with this practice enabling to devise an approach or strategy deriving maximum environmental and economic benefits.