Dr. Jian-ming Xu is a soil scientist with particular interests in the field of the chemical and biochemical processes of contaminants in soil, characterization of soil humic substances, and impact of soil environmental quality on food safety. He is now a leading scientist and the Director of Soil and Water Resources & Environmental Science at Zhejiang University, the Chair of ... Read moreSoil Chemistry Division of Soil Science Society of China, and the Coordinator of Chinese Chapter of International Humic Substances Society. He has published over 200 scientific papers, notably in top international journals as Soil Biology & Biochemistry, etc. Dr. Donald L. Sparks is S. Hallock du Pont Chair of Soil and Environmental Chemistry, Francis Alison Professor, and Chairperson, Department of Plant and Soil Sciences at the University of Delaware at Newark. He also holds joint faculty appointments in the Departments of Civil and Environmental Engineering and Chemistry and Biochemistry, and in the College of Marine Studies. In 2006, he was appointed as Director of the Center for Critical Zone Research, a university wide center dealing with environmental science and engineering. His discoveries on the formation and role of surface precipitates in the retention, fate and transport of metals in natural systems have received worldwide attention and had major impacts in the areas of sorption models, metal speciation and soil remediation/contamination. He has (co-)authored and edited over 200 publications. He served as Co-Editor-in-Chief of Geoderma and on the Editorial Boards of Soil Science, Advances in Agronomy, Pedosphere, Geochimica Cosmochimica Acta, and Vadose Zone Journal. At the University of Delaware, Dr. Sparks was instrumental in building the soil science program, including the establishment of the federally funded Institute of Soil and Environmental Quality (ISEQ) and the establishment of the UD Center for Critical Zone Research (CCZR). Dr. Sparks has been the recipient ofnumerous awards and honors. Show Less