Past, present and future of composting research

Concerns have been raised by some researchers that there is no future in compost research. This paper attempts to take an overview of composting and to set it in a historic context. Composting represents one of the most widely utilised technologies for organic waste recycling in agriculture, which has been used by mankind for many thousands of years: accounts go back to Chinese records from over 5000 years ago. Largely unchanged until early in the 20th century, it is only in the last 50 years or so that effective research has been carried out, on both the composting process and use of the compost product. Much of this research has been driven by the increasing need to find an alternative to landfill for biodegradable wastes, the importance of compost quality and the implementation of compost quality standards. Looking through past research, it is apparent that some researchers have been better at disseminating the results of their work than others. The importance of dissemination is considered, together with the available routes through publications, conferences, networking and outreach. The future of composting is closely linked to the interests of researchers, governments and other funding agencies. Despite the great deal of research over the past 50 years, certain areas are identified where it is considered that work is needed. These include: pathogen identification and control, modelling feedstock and process variations, assessing health impacts of compost and the use of modern tools such as DNA extraction for pathogen enumeration. Composting will continue to be an important process both on its own, particularly in developing countries, and as a complementary process for systems such as anaerobic digestion in industrialised countries. In terms of the compost product, researchers are looking at ways of enhancing its value and performance, for example with the use of biochar. In addition, there are certain components of the compost, such as phosphate, for which supply options are diminishing, and it is important that we recognise the opportunity for compost to supply these needs.