Enhancing the California Forestry-Agriculture Nexus By Recovering the Energy and Resource from Waste Streams

California is a wildfire-prone state facing the challenge of destructive wildfires because of the poor forest management and climate change. To constrain the progress of wildfires, lots of hazardous woody biomass are generated due to the tree trimming and man-made firebreak. Also, California is a worldwide productive agricultural region and is the largest producer of agricultural products in the US. California has most nation's top ten agricultural counties and generates over 20 million dry tons of agricultural waste streams annually. On the other hand, California is experiencing long-term drought due to the climate change. Hence, soil moisture retention in agriculture is always a challenge. Using biochar soil amendment is a recognized method to improving the resilience to heat waves by increasing the soil water and nutrient retention capacity and improving the soil microbial communities. Pyrolysis is a commercialized technology that can be used to convert carbonaceous waste from both forestry and agriculture to biochar, bio-oil, and pyrolysis gas for energy and resource recovery. Though pyrolysis is not a new technology, the pyrolysis performance of different types of woody biomass and agricultural waste and their derived biochar properties in California have never been evaluated systematically. In this study, all the major waste streams from both forestry and agriculture (e.g. redwood, chaparral, orchard pruning, cow manure) were pyrolyzed to analyze the mass and energy balance. The plant growth-promoting properties of the waste-derived biochar were also evaluated. The preliminary results showed that biochar is a sustainable solution to enhancing the California forestry-agriculture nexus.