Composting in Sri Lanka: Policies, Practices, Challenges, and Emerging Concerns

Abstract

Compost is a widely accepted organic fertiliser throughout the world. It is being produced using a wide variety of source materials at household to commercial scale. With the increased population and changes in food consumption pattern tending towards a vegetable- and meat-rich diet, the amount of organic waste generated in urban and peri-urban settings has increased. Many governments promote composting as a process that helps them to reduce the volume of organic waste and recycle nutrients back to croplands. Some examples of organic waste accumulated in large scale include household waste from urban and peri-urban settings, sewage, animal farm waste, agricultural waste from large-scale markets, food debris, and kitchen waste from hotels. The composition of compost varies in a wide range depending on the nature of materials used to produce it. The safety concerns related to compost also vary along the same line. The quality of compost has become a subjective term that means different aspects to different bodies due to a lack of commonly agreed standards to regulate the composting process and the final product itself. Recent research findings indicate that compost can serve as a carrier of potentially toxic trace elements, organic pollutants, and determinants of antimicrobial resistance to the environment and along the food chain. Producing good-quality compost safe to human health and the environment at large has become a challenge that should be addressed at various levels: from production to policymaking. This chapter discusses some of the major challenges faced in Sri Lanka with compost making. To prepare the background for this discussion, information on the policies and current practices of nutrient management in Sri Lanka is also presented. The context may be applicable to many other developing countries in the tropics.

Compost Quality and Markets Are Pivotal for Sustainability in Circular Food-Nutrient Systems: A Case Study of Sri Lanka

“…Several stakeholders participating in this project expressed concerns about the quality of compost derived from biodegradable MSW, echoing concerns stated in the literature ( Basnayake and Visvanathan, 2014;Samarasinha et al, 2015;Waqas et al, 2017;Fernando, 2019;Dandeniya and Caucci, 2020). These concerns largely fall into two categories: (1) contamination and (2) limited benefits for crops.…”

“…The Sri Lanka MSW compost standard specifies that composts be free of visible non-biodegradable materials except sand (Sri Lanka Standards Institution, 2019). Sieving of finished compost helps facilities meet this requirement despite foreign matter (especially plastic) present in the MSW feedstocks (Dandeniya and Caucci, 2020). However, this standard and other existing ones do not necessarily guarantee that composts are free of microplastics, or other pollutants of emerging concern (Dandeniya and Caucci, 2020;Gui et al, 2021).…”

“…It has been estimated that establishing facilities to recycle organic waste in Sri Lanka could decrease total waste management and chemical fertilizer costs by US$191 million to US$357 million, depending on the level of inter-provincial trade (Bekchanov and Mirzabaev, 2018). However, contamination of MSW-derived compost is a concern, with potential contaminants including pathogens, microplastics, potentially toxic elements, antibiotic resistance determinants, and other inorganic and organic pollutants, several of which remain infrequently measured (Dandeniya and Caucci, 2020;Gui et al, 2021). Compost quality, a concept which includes maturity and stability, physical and chemical properties, and pollutants, is inherent to the definition of compost: "the stabilized and sanitized product of composting, which has undergone an initial, rapid stage of decomposition, is beneficial to plant growth and has certain humic characteristics" (Bernal et al, 2009(Bernal et al, , 2017.…”

“…Compost quality standards are needed to address specific concerns and general skepticism among potential compost buyers to help ensure adequate product markets (Samarasinha et al, 2015;Fernando, 2019). Currently, Sri Lanka Standard SLS 1634:2019 includes specifications for compost made from MSW, including general physical, chemical, microbiological, and biological requirements, as well as limits for potentially toxic elements (Sri Lanka Standards Institution, 2019;Dandeniya and Caucci, 2020).…”

“…Basnayake and Visvanathan (2014) suggested that composting efforts in Sri Lanka have failed due to poor compost quality, high operational costs, and lack of financing. Furthermore, others observed that nuisance odors, leachate pollution, and increased density of wild animals and flies have negatively affected perceptions of composting operations in some regions, leading to protests, lack of compost business development, and lack of effective compost use (Samarasinha et al, 2015;Dandeniya and Caucci, 2020). Fernando (2019) identified a large number of institutional, economic, and social factors that influence solid waste management in Sri Lanka, including numerous factors that are particularly relevant for biodegradable MSW.…”