Prof. Nanthi Bolan1
1University Of Newcastle, Newcastle, Australia
Co-composting biowastes such as manures and biosolids can be used to stabilize carbon (C) without impacting the quality of these biowastes. This study investigated the effect of co-composting biowastes with alkaline materials on C stabilization, and monitored the fertilization and revegetation values of these co-composts. The stabilization of C in biowastes (poultry manure and biosolids) was examined by their composting in the presence of various alkaline amendments (lime, fluidized bed boiler ash, flue gas desulphurization gypsum, and red mud) for 6 months in a controlled environment. The effects of co-composting on the biowastes’ properties were assessed for different physical C fractions, microbial biomass C, priming effect, potentially mineralizable nitrogen, bioavailable phosphorus, and revegetation of an urban landfill soil. Co-composting biowastes with alkaline materials increased C stabilization, which is attributed to interaction with alkaline materials, thereby protecting it from microbial decomposition. The co-composted biowastes also increased the fertility of the landfill soil, thereby enhancing its revegetation potential. Stabilization of biowastes using alkaline materials through co-composting maintains their fertilization value in terms of improving plant growth. The co-composted biowastes also contribute to long-term soil C sequestration and reduction of bioavailability of heavy metals. Furthermore, of the materials used in this study, the co-composted biosolids with lime were found to be the most suitable for SOM storage due to its low priming effect. Although the addition of industrial byproducts such as coal combustion products improves the value of composts in relation to increasing revegetation potential, reducing heavy metal bioavailability and enhancing C sequestration, cost, and availability of these materials must be taken into consideration in field scale applications.
Biography: Professor Nanthi Bolan’s teaching and research interests include agronomic value of manures, fertilisers and soil amendments, soil acidification, nutrient and carbon cycling, pesticide and metal pollutants interactions in soils, greenhouse gas emission, soil remediation, mine site revegetation, and waste and wastewater management. Nanthi is a Fellow of American Soil Science Society, American Society of Agronomy and New Zealand Soil Science Society, and was awarded the Communicator of the Year award by the New Zealand Institute of Agricultural Sciences. He has supervised more than 50 postgraduate students, and was awarded the Massey University Research Medal for excellence in postgraduate students’ supervision. He has published more than 300 book chapters and journal papers, and is one of the Thomson Reuters Highly cited researchers for 2018.