Donald L. Sparks


  • Ph.D. – Soil Science – Virginia Polytechnic Institute and State University
    Dissertation: Potassium Adsorption and Desorption Kinetics in a Soil System and Its Relation to Plant Uptake
  • M.S. – Soil Science – University of Kentucky
    Thesis: Physical, Mineralogical, and Chemical Properties, Including Ammonium Distribution, in the Shrouts Soils of Kentucky
  • B.S. – Agronomy – University of Kentucky

Current Courses


Research in the Environmental Soil Chemistry Laboratory focuses on how toxic metals such as arsenic (As), nickel (Ni), and zinc (Zn) and plant nutrients such as phosphorus (P) and sulfur (S) are bound (sorbed) on soils. We conduct these studies under different environmental and experimental conditions (pH, time, temperature, hydration state, presence of microbes) to best represent the natural environment. We use bright light sources generated at synchrotron facilities (associated with National Laboratories) to determine the forms (species) of the metals and nutrients in the soil at the molecular scale. This information is necessary to make accurate predictions about how easily the contaminant will leach into the water supplies, and determine its toxicity and bioavailability to plants, animals, and humans. We also conduct speciation research on metal contaminated soils and on plants that accumulate large quantities of metals (hyperaccumulators). The results of these studies are useful in developing effective strategies for soil remediation.

Professional Activities

Dr. Donald L. Sparks is Unidel S. Hallock du Pont Chair of Soil and Environmental Chemistry, Francis Alison Professor, and former 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 Earth, Ocean, and the Environment. He joined UD in 1979 and served as Assistant Professor at the University of Delaware from 1979-1983, Associate Professor from 1983-1987, Professor in 1987-1994, Distinguished Professor from 1994-2001 and T. A. Baker Professor from 2001-2002. In 1986, he served as a Visiting Professor at the University of California in Riverside and in 2005 at INRA in Aix-en-Provence. He served as Assistant Department Chairperson from 1983-1985 and served as Chair of the Department of Plant and Soil Sciences from 1989-2009. In 2006, he was appointed as Director of the Center for Critical Zone Research. In 2009, he was appointed Director of the Delaware Environmental Institute (DENIN), a statewide institute housed at the University of Delaware that integrates environmental science, engineering, and policy (

Dr. Sparks is internationally recognized for his research in the areas of: kinetics of soil chemical processes, surface chemistry of soils and soil components using in situ spectroscopic and microscopic techniques and the physical chemistry of soil potassium. He has pioneered the application of chemical kinetics to soils and soil minerals including development of widely used methods, elucidation of rate-limiting steps and mechanisms, and coupling of kinetic studies with molecular scale investigations, particularly synchrotron based x-ray absorption spectroscopy. 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 is the author, coauthor, or editor, of 441 publications (h-index=66 and >12,000 citations; Web of Science). These include: 14 edited books, 59 book chapters, and 264 refereed papers. He is the author of three widely adopted textbooks, Kinetics of Soil Chemical Processes and Environmental Soil Chemistry (1st and 2nd editions), published by Academic Press. He is the editor of the most prestigious serial review in the fields of crop and soil science, Advances in Agronomy. He has edited 101 volumes of Advances in Agronomy since assuming the editorship in 1991. He has made 258 invited presentations on his research findings at universities, conferences, and institutes nationally and internationally, including serving as speaker at 114 universities and institutes in the United States, Canada, South America, Asia, Australia, and Europe. The latter include a number of distinguished lectureships.

Dr. Sparks has been the recipient of over $67 million in grants and contracts from a number of governmental, academic and industrial sources including the Agency for International Development, Potash and Phosphate Institute, Departments of Agriculture, Interior, and Energy, Environmental Protection Agency, University of Delaware Research Foundation, the National Science Foundation (NSF), United States Borax Corporation, U.S.-Israel Binational Research and Development Fund, Bikini Atoll Rehabilitation Committee, the DuPont Corporation, the Unidel Foundation, and NASA.

Dr. Sparks has served as an invitation reviewer for numerous manuscripts in scientific journals and for grant proposals to the National Science Foundation, the Agency for International Development, U.S. Geological Survey, the Department of Energy, the USDA, the EPA, the Canadian Research and Engineering Council and the Swiss National Science Foundation. He has served on the Editorial Boards of the Soil Science Society of America Journal (as Associate Editor, 1985-1987, Div. S-2, and as Technical Editor, Div. S-2, S-5, and S-9, 1988-1993). He served as Co-Editor-in-Chief of Geoderma and on the Editorial Boards of Soil Science, Advances in Agronomy, Pedosphere, Geochimica Cosmochimica Acta, Vadose Zone Journal, and Chemical Geology.

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) and the Delaware Environmental Institute (DENIN). He has been very active in graduate education. He has served as major professor and mentor to 62 graduate students and 33 postdoctoral fellows who hold positions in academe, government, and industry in the U.S.A. and throughout the world. He has also served as host to Visiting Scholars and Professors from around the world. His graduate students have been the recipients of numerous awards and honors including Potash and Phosphate Institute International Fellowships (five students), UD Theodore Wolf Dissertation Prize in the Physical and Life Sciences (three students), University of Delaware Fellowships, Outstanding Northeastern Regional Agronomy Society Graduate Student Awards, NASA, NSF, DoD, EPA and USDA Graduate Fellowships. Two Ph.D. students, Drs. Christian P. Schulthess and Scott E. Fendorf, were the recipients of the Emil Truog Award from the Soil Science Society of America. Three of his students have received The Presidential Achievement Award from the University of Delaware and three students have received U.S. Presidential Early Career Awards in Science and Engineering. In 1999, Dr. Andre M. Scheidegger, a former postdoctoral associate, received the F.W. Clarke Medal from the Geochemical Society of America, the first soil scientist to receive this award.

Dr. Sparks served on the Scientific Advisory Committees of the Advanced Light Source at Lawrence Berkeley National Laboratory, the Center for Environmental Molecular Science (EMSI) at the State University of New York at Stony Brook, the users’ executive committee at the National Synchrotron Light Source at Brookhaven National Laboratory, and the Steering Committee of the Institute of Soil and Environmental Quality (ISEQ) at the University of Delaware. Dr. Sparks has also served on several committees of the National Research Council/National Academy of Sciences (NAS), including serving as Chair, NAS U.S. National Committee for Soil Sciences. He has consulted with a number of major industries.

Awards and Honors

Dr. Sparks has been the recipient of numerous awards and honors. In 1982, he was the recipient of the University of Delaware Potash Institute for his outstanding research on soil potassium. In 1985, he was recipient of the American Society of Agronomy’s Visiting Scientist Award and in 1986 he received the Research Award from the Northeastern Branch, American Society of Agronomy. In 1987, Dr. Sparks was elected Chairman of the Soil Chemistry Division (Div. S-2) of the Soil Science Society of America. In 1989, he was named a Fellow of both the American Society of Agronomy and the Soil Science Society of America, the most prestigious honors given by both societies. In 1991, he received the F.D. Chester Distinguished Performance Award from the College of Agricultural Sciences and the M.L. and Chrystie M. Jackson Soil Science Award from the Soil Science Society of America. In 1994, he was named Distinguished Professor of Soil Science, the first such professorship in the College of Agricultural Sciences at the University of Delaware. In 1994, Dr. Sparks also received the Soil Science Research Award from the Soil Science Society of America and was elected Vice-Chair (Commission II, Soil Chemistry) of the International Society of Soil Science. In 1996 Dr. Sparks was the recipient of the University of Delaware’s Francis Alison Award, which is the highest award that a faculty member can receive. The award is given for distinguished achievements in scholarship and one in profession, teaching, dedication and service to the university, and mentoring of students. In 1997, Dr. Sparks was elected Fellow of the American Association for the Advancement of Science. In 1998, he was elected President of the Soil Science Society of America and Chairman of Div. 2 (Soil Chemistry) of the International Union of Soil Sciences. In 2000, he was selected as President-Elect of the International Union of Soil Sciences, and installed as President in 2002. In 2001, he received the prestigious McMaster Fellowship from CSIRO, Australia. In 2001, he was named the T. A. Baker Professor of Plant and Soil Sciences. In 2002, he received the University of Kentucky’s Chapter of Gamma Sigma Delta Outstanding Alumnus Award, was the first recipient of the University of Delaware’s Outstanding Doctoral Graduate Student Advising and Mentoring Award, and was named S. Hallock du Pont Chair of Plant and Soil Sciences. In 2003, he received the Gold Medal for Distinguished Achievements in research from the Polish Society of Soil Science and the Environmental Quality Research Award from the American Society of Agronomy. In 2005, he was named the Sterling B. Hendricks Memorial Lecturer by NSDA-ARC. In 2007, he received distinguished alumni awards from the University of Kentucky and Virginia Tech and was named an Honorary Member of the Polish Society of Soil Science. In 2008, he was elected Fellow of the Geochemical Society and the European Association of Geochemistry. In 2010 he received the Geoffrey Marshall Mentoring Award from the Northeastern Association of Graduate Schools and the Liebig Medal from the International Union of Soil Sciences. In 2011, he was one of 20 scientists/engineers from around the world to receive an Einstein Professorship from the Chinese Academy of Sciences, and was granted an Honorary Professorship from the Institute for Urban Environment, Xiamen, China. In 2012 he was granted an Honorary Professorship from Huazhong Agricultural University, Wuhan, China and elected as an Honorary Member of the International Union of Soil Sciences. In 2015 he was the recipient of the Geochemistry Medal from the American Chemical Society, the Honorary Professor at Nanjing University, Nanjing, China, and the Honorary Professor at the Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China. In 2016 he received the Pioneer in Clay Science Award from the Clay Minerals Society.

Recent Publications



Contact Information
Donald L. Sparks

Unidel S. Hallock du Pont Chair and Director, Delaware Environmental Institute

Plant and Soil Sciences
250A Harker ISE Lab

Newark, DE 19716
Phone: (302) 831-3436