Mark’s research has centred on assessing the effects of contaminants associated with a range of organic waste amendments applied to field soils; their effects on crop production and product quality, soil health, particularly from the viewpoint of soil microbial functionality, and soil chemistry including the medium to long-term sorption of applied contaminants by soil and soil components. His work has contributed to the formulation of regulatory guidelines designed to allow the safe reuse of organic amendments such as biosolids. He has also studied the effects of various processes such as soil acidification, on the long-term suitability of applying waste materials as soil amendments. He is currently involved with research investigating the use of a range of municipal waste materials as soil amendments and this work includes assessing the effects of a range of inorganic and organic contaminants on crop production, soil chemistry and soil microbial function. Opportunities are now being presented to couple his research on the long-term bioavailability of contaminants in organic amendments, with the efficacy of using these materials for enhanced sequestration of C in soils. He has also carried out studies using various waste materials that may aid in the amelioration of contaminated agricultural soils.