Wenqiao Yuan, Ph.D., Professor, Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695 USA

Dr. Wenqiao Yuan is a professor at North Carolina State University. He is a titled University Faculty Scholar (Provost's Professor), and a recipient of many prestigious national and international honors and awards, such as the U.S. National Science Foundation “CAREER Award”, the American Society of Agricultural and Biological Engineers “New Holland Young Researcher Award”, “Rain Bird Engineering Concept of the Year Award”, “Boyd-Scott Graduate Research Award”, “Superior Paper Award”, and “Distinguished Service Award”. Dr. Yuan has published more than 110 SCI/EI articles and 4 book chapters with over 1840 citations and an h-index of 21. He has advised 22 Ph.D. and 8 M.S. students and supervised more than 40 scholars and undergraduate research assistants in the last 10 years. Dr. Yuan is an associate editor of three SCI journals, and has been the chair of several technical committees of his professional societies. He is nationally and internationally recognized for his research and educational accomplishments in renewable energy and products, and has been invited to speak in many institutions and conferences worldwide.

Speech Title: Biochar benefiting green agriculture and global warming

Abstract
Biochar is charcoal produced from biomass via pyrolysis or gasification. It has been traditionally used as a soil amendment due to its positive effects on soil nutrient status, microbial community, and soil biota or plant growth. Recently, the chemical stability of biochar and its slow degradation has attracted interests in using biochar as a carbon sink to reduce greenhouse gas emissions, mainly carbon dioxide (CO₂) and methane (CH₄). Biochar has also demonstrated its potential in reducing nitrous oxide (N₂O) emission, which is attributed to the high porosity and large surface area of biochar that enables absorption/adsorption of water, ammonia or water-soluble ammonium, as well as nitrate ions. Extensive research has focused on the addition of biochar to soils for mitigating CH₄ and N₂O emissions during laboratory or greenhouse incubations under various conditions. Applications included multiple ecosystems, such as soybeans, grass ecosystems, common beans, rice production, and wheat plots subjected to different agricultural soil management practices such as tillage, baling, and crop rotation.
In this study, the effect of biochar addition was examined relative to biochar-chicken manure co-composting and its associated CH₄, CO₂ and N₂O emissions as well as nitrogen (N) transformation. The results demonstrated that biochar addition was more effective in accelerating the composting process, indicated by a 5.2% increase in peak pile temperature and a 148% increase in peak CO₂ emission with 20% biochar amended-compost, compared with the control that had no biochar. The addition of 20% biochar also resulted in a 54.9% decrease in peak CH₄ emission and 59.8% decrease in the major peak of N₂O emission compared with the control. Ammonium (NH₄⁺_-N) and nitrate (NO₃^-_-N) contents in the final product with 20% biochar addition increased by 67.3% and 66.7%, respectively, compared to the control, meaning more nutrient retention. Overall, biochar can be an ideal bulking agent for stabilizing N-rich materials to minimize N₂O and CH₄ emissions for green agriculture and global warming mitigation.