Regional Considerations for Targeted Use of Biochar in Agriculture and Remediation in Australia

Abstract

This chapter provides an overview of biochar research within Australia with consideration given to the regional land‐use diversity in defining both the dominant feedstock materials used and the dominant target systems. Carbon sequestration and greenhouse gas (GHG) mitigation have been strong underlying themes of Australian biochar research, with contaminant focus on its use as a soil amendment in agriculture. Clear messages from the research are often hampered by the high level of variation reported in key study parameters, including the biochar types used and the soil environments they are applied to. Nevertheless, field trials within the eastern agricultural region support the wider global view that highly weathered acidic soils (e.g., Ferrosols) provide a good target system where biochar can improve pH and nutrient availability and reduce Al toxicity. The results from the southern and western regions are more limited and inconsistent and currently leave the potential use in legume rotations unexplored. The risk of reduced herbicide efficacy is of particular relevance to Australia. Herbicide resistance is a growing problem, and adoption of no‐till practices is dependent on effective and economic weed control; therefore, field scale assessment of the impact of biochar is required. Interest in the use of biochar as a soil remediation and rehabilitation tool has been slow to appear in Australia, but there is growing interest for bauxite rehabilitation, heavy‐metal remediation, and management of acid‐sulfate soils. Building on growing understanding of the sorptive and reactive characteristics of biochar, there has been a shift toward the type of targeted and integrated approaches required to overcome adoption barriers, for example, as part of enhanced C fertilizers. The development of integrated biochar approaches in agriculture and environmental management is intrinsically linked to establishment of a bioenergy industry, which is currently fragmented in Australia.