An official website of the United States government.

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Agency Biographies

Dr. Shefali V. Mehta

Deputy Under Secretary of Research, Education, and Economics and Acting USDA Chief Scientist

Dr. Shefali Mehta is the Deputy Under Secretary for the Research, Education, and Economics mission area, which is comprised of the Agricultural Research Service, Economic Research Service, National Agricultural Statistics Service, the National Institute of Food and Agriculture, and the Office of the Chief Scientist. Together these organizations cut across every USDA department and have a unique responsibility to advance agricultural research, extension, and education.

As an environmental and agricultural economist and statistician, Dr. Mehta comes to USDA from Open Rivers Consulting Associates, a science & technology and management consulting firm she founded and led. In her role as founder and principal, she helped clients intertwine innovation, data and science, compassion, diversity of perspectives and the importance of the environment for overall health into their skills and values.

Over the course of her career, she has worked in roles across private, public and non-profit sectors including McKinsey, Syngenta, the Soil Health Partnership, the Minnesota Office of Higher Education, St. Olaf College, and the American Cancer Society. She has also served as a Board or Advisory Council member of several organizations: the conservation organization Pheasants Forever and Quail Forever (also served as Vice Chair of the Board, the first woman to hold this position), Bountifield, Minnesota Invasive Terrestrial Plants and Pest Center, the School of Statistics at University of Minnesota, The Gates Scholar Advisory Council, amongst others.

Originally from New England, Dr. Mehta received her Ph.D. in Agricultural and Applied Economics and M.S. in Statistics from the University of Minnesota, M.Phil. in Economics from Cambridge University, and a B.A. in Economics from New York University.

    Dr. Shefali Mehta, Deputy Under Secretary for the Research, Education, and Economics mission area.

    Dr. Chavonda Jacobs-Young

    Administrator, Agricultural Research Service

    Dr. Chavonda Jacobs-Young is the Administrator for the Agricultural Research Service (ARS). Dr. Jacobs-Young recently served as the Acting Deputy Under Secretary of the REE mission area.  Previously, she served as ARS Associate Administrator for National Programs, where she led the Office of National Programs which manages the research objectives of the Agency. Dr. Jacobs-Young also led the Office of International Research Programs which is responsible for ARS' liaison with its international partners.

    Prior to moving into her role at ARS, Dr. Jacobs-Young served as the Director of the Office of the Chief Scientist in the U.S. Department of Agriculture, where she was responsible for facilitating the coordination of scientific leadership across the Department to ensure that research supported by, and scientific advice provided to, the Department and external  stakeholders were held to the highest standards of intellectual rigor and scientific integrity. She also served as the Acting Director for USDA's National Institute of Food and Agriculture.

    Dr. Jacobs-Young was a senior policy analyst for agriculture in the White House Office of Science and Technology Policy where she supported the President's science adviser and others within the Executive Office of the President on a variety of agricultural scientific activities and worked across the Federal Government to improve interagency cooperation and collaboration on high-priority scientific issues.

    Dr. Jacobs-Young is a native of Georgia. She holds M.S. and Ph.D. degrees in Wood and Paper Science and a B.S. degree in Pulp and Paper Science and Technology from North Carolina State University. She also is a graduate of American University's Executive Leadership in Public Policy Implementation Program.

    Dr. Chavonda Jacobs-Young

    Hubert Hamer

    Administrator, National Agricultural Statistics Service

    Hubert Hamer has served as NASS Administrator since 2016. He brings extensive experience in all aspects of the agency’s work. Before becoming administrator, he served as director of the Statistics Division, which produces and releases more than 400 national statistical reports each year covering the agency’s crops, livestock, economic, demographic, environmental, and census programs. He also served as executive director of the NASS Agricultural Statistics Board (ASB) and executive director of the Advisory Committee on Agriculture Statistics.

    From 2010 until he became head of the Statistics Division, Hamer was chair of the Agricultural Statistics Board. As ASB chair, he led the preparation and dissemination of market-sensitive reports compiled and issued under special security conditions known as Lockup. He was also responsible for promotion and outreach of the NASS mission to all stakeholders. From May 2000 until April 2010, Hamer served as associate deputy administrator for field operations, overseeing 24 state field offices as well as the Training and Career Development Office.

    Since joining NASS, Hamer has served in a number of capacities in Washington, D.C. as well as the Louisiana, Illinois, and Missouri field offices. While directing the Missouri office, he completed USDA’s Senior Executive Candidate Development Program and was appointed to the Senior Executive Service in 2000. Hamer completed the program for Senior Managers in Government at Harvard University’s John F. Kennedy School of Government in 2004 and completed the Office of Personnel Management (OPM) Executive Potential Program in 1994. As part of the OPM program, he served as a fellow with the Senate Budget Committee and worked on the staff of the Secretary of Agriculture.

    Hamer was born on a small livestock and row crop farm in Benton County, Mississippi, and later continued his development in Grand Junction, Tennessee. He is a graduate of Tennessee State University.


    Hubert  Hamer

    Dr. Dionne Toombs

    Acting Director, National Institute of Food and Agriculture

    Dr. Dionne Toombs is the Acting Director of the National Institute of Food and Agriculture, the U.S. Department of Agriculture’s extramural grant funding agency for agricultural research, education, and Extension programs across the nation. Previously, she was Director of the Office of the Chief Scientist, where she led a wide range of issues affecting science programs and science policy in agricultural research, education, and economics. 

    Dr. Toombs also provided scientific leadership and coordination to the White House, Office of Science and Technology Policy, National Science and Technology Council working groups, across USDA and other federal agencies, and the agricultural community. 

    With over a decade of USDA service, Dr. Toombs was the Division of Nutrition at NIFA where she led USDA nutrition science leaders who helped steer science policy and program development to ensure America’s food supply is safe, nutritious, and accessible to all citizens. She was the National Program Leader for NIFA’s Agriculture Food and Research Initiative, leading large competitive grant programs to fund research into nutrition, food science and technology, and food safety and as a Program Specialist for Food Science and Nutrition at the former USDA Cooperative State Research Education and Extension Service, which is now NIFA. 

    Since she started at USDA as a student intern at USDA’s Agricultural Research Service, Dr. Toombs has been repeatedly featured as one of USDA’s most impactful woman scientists and recognized by the Secretary of Agriculture for outstanding leadership. Throughout her career, she has helped her colleagues, staff, and students maximize their potential by bolstering their talents and developing their leadership skills. Always willing to champion the next generation of scientists, she often emphasizes the importance of relationship building, citing collaboration as a key to her success. 

    Dr. Dionne Toombs

    Dr. Spiro Stefanou

    Administrator, Economic Research Service

    Spiro Stefanou is the Administrator of the Economic Research Service. He provides leadership and guidance for the agency research, analytical, and technical operations. Since 2015, Dr. Stefanou was a Professor of Economics in the Food and Resource Economics Department at the University of Florida.

    Prior to his time at the University of Florida, Dr. Stefanou was Professor of Agricultural Economics at Penn State University since 1983. 

    He is a Distinguished Fellow of the Agricultural and Applied Economics Association and was a Marie Curie Senior Fellow at the University of Crete (Rethymnon, Greece), Mansholt Senior Fellow at Wageningen University (Netherlands), and Jean Monnet Fellow at the European University Institute (Florence, Italy).  He has been a visiting professor at the Institute for Advanced Studies (Vienna, Austria), and the Mediterranean Agronomic Institute (at Chania).  Dr. Stefanou has served on the editorial boards of six national and international journals. 

    Dr. Stefanou received his Ph.D. in Agricultural Economics from the University of California, Davis, his M.S. in Agricultural and Resource Economics from the University of Maryland and a Bachelor of Arts in Anthropology from George Washington University.

    Dr. Spiro Stefanou, Administrator, ERS

    Richard C. Derksen, Ph.D.

    Acting Director for the Office of the Chief Scientist

    Dr. Richard (Rich) Derksen is Acting Director of the Office of the Chief Scientist (OCS). In this capacity, he supports the Chief Scientist in leading cross-cuttingstrategic planning and collaboration activities for science programs that support scientific excellence, innovation, and capacity to achieve USDA’s mission. OCS works to preserve and promote the integrity of USDA-supported research and scientific decision-making. The Office also leads strategic international Science and Technology engagements for USDA’s Chief Scientist and works to ensure equitable access to USDA science information. 

    Dr. Derksen has more than 25 years of engineering research experience. He is an internationally recognized expert in crop production and protection engineering. Dr. Derksen began his career at USDA in 1996 when he joined the Agricultural Research Service as a research scientist. He has authored more than 200 publications, including 78 peer-reviewed journal manuscripts, and he has given numerous invited presentations at national and international scientific meetings. Dr. Derksen received his Master of Science and Ph.D. degrees in Agricultural Engineering from the University of Illinois and he received his Bachelor of Science in Agricultural Engineering from Purdue University. He previously held a faculty research and extension appointment at Cornell University. Dr. Derksen is originally from Indiana and has engaged his local communities as a 4-H advisor, neighborhood association leader, and substitute teacher. 

    Dr. Richard (Rich) Derksen is Deputy Director of the Office of the Chief Scientist