Designing Specific Biochars to Address Soil Constraints: A Developing Industry

Introduction 1 The Physical and Chemical Nature of Biochars 1.1 Complexity of the Carbon Matrix 1.2 Mineral Phases 1.3 Properties of Biochars as a Function of Process Conditionsand Feedstock 1.4 Effect of Biochar Properties on Crop Yields: A BriefSummary 1.5 Implications for Developing More Plant Effective Biochars 2 An Overview of Indigenous and Historical Practices forProducing and using Biochar Mixes 2.1 Australian Aborigines 2.2 Amazon in Brazil2.3 Africa 2.4 Asia 2.5 Key Features of Traditional Practices that can Assist inDeveloping More Plant Effective Biochars 3 Biochars Aged in Soils and their Relevance to Design ofSpecifi c Biochars 3.1 Understanding the Aging Process 3.2 Implications for the Design of Biochars 4 Enhancing Properties of Biochars and Producing Blends toMeet Soil and Plant Requirements 4.1 Blending Biochars 4.2 Alkaline Pre and Post Treatment 4.3 Acid Pre and Post Treatment 4.4 Pretreatment of Biomass with Minerals 4.5 Post Treatment with Organic Matter, Minerals orChemical Fertilisers 4.6 Aerobic and Anaerobic Composting with Biochar 5 Future Directions in the Development of Enhanced Biochars ReferencesApplication of biochar produced in open fi res or simple kilns mixed with mineral and organic matter is an ancient practice (Lehmann and Joseph 2009). In Japan and China the smoke produced in simple kilns is condensed and refi ned (known as wood viniger), and then used with the biochar or as a foliar spray. Considerable data on impact of plant growth has been generated from studying the traditional practices in the Amazon, Asia and Africa (Joseph et al. 2010). Data have been published on the chemical composition and physical structure of what are known as black carbon (BC) particles that come from soils where biochar has been applied in the past (Liang et al. 2006).