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Dr. Raymond Weil



Professor Ray R. Weil is an internationally recognized expert on soil science, nutrient cycling, soil organic matter and cover crop systems for soil health and water quality. His methods for soil microbial biomass and active Carbon are adopted by USDA/NRCS and researchers worldwide. His research on multi-purpose cover crops and ecological approaches to soil management is used by landscape managers and farms, large and small. He has advised on food security and soil management in Africa and other developing regions. He teaches undergraduate and graduate-level courses in soil science, soil fertility and sustainable agriculture. His textbook, The Nature and Properties of Soils, is the most widely used soils textbook in the US and around the world.

Environmental Science & Technology 0115 HJ Patterson Hall 4065 Campus Dr. College Park, Maryland 20742
For Package Delivery Dock H, AnSc-AgEng Bldg. #142 8127 Reagents Drive College Park, Maryland 20742


  • soil science
  • agronomy
  • soil health
  • sustainable agriculture
  • International Development
  • Cover Crops
  • soil fertility
  • soil organic matter
  • soil carbon
  • soil compaction
  • Soil Conservation
  • Nitrogen cycling
  • Phosphorus
  • Sulfur

Professional Activities


I am dedicated to researching and promoting the adoption of soil health practices, especially more sustainable agricultural systems in both industrial and developing countries. My research focuses on soil management for enhanced soil health and nutrient cycling for productivity, water quality, and sustainability. I have also been a dedicated educator at all levels for more than 40 years, having taught over 6,500 undergraduate and graduate students in his university courses, addressed over 5000 farmers at meetings and field days, and helped train hundreds of researchers and managers in numerous companies and organizations. I have been privileged to be the major advisor for over 42 MS and Ph.D. students. The undergraduate and graduate courses I have developed and taught include two introductory courses, Soil and Environmental Quality (ENST105) and Fundamentals of Soil Science(ENST200), and three upper-level courses: Principles of Soil Fertility(ENST411), Issues in Sustainable Agriculture(ENST441), and Advanced Soil-Plant Relationships(ENST611). I aim to engage students with enthusiasm for soil science and open their eyes to the many ecological roles played by soils, but also maintain high standards and rigorous grading.

My program at the University of Maryland attempts to integrate all three legs of the Land Grant University Mission, teaching, extension, and research, in a manner that benefits all three. My teaching philosophy is summarized by three “I”s: inspire, integrate, and inform. Students in the classroom are energized by hearing first-hand accounts of soils problems and investigations and benefit by learning science from an active scientist. At the same time, the classroom discussions of cutting-edge concepts often inspire my graduate students and me to work on new research ideas.  I view my extension activities provide a two-way flow of ideas to and from regional and global farmers and other soil management practitioners.  The synergism between teaching and research and my ecological approach to soil science find their ultimate expression in my work as author of the most widely used textbook in soil science, The Nature and Properties of Soils

My research program combines three interrelated areas: 1) Organic Matter Management for Soil Health; 2) Sustainable Farming Systems, and 3) Soil Management for Improved Nutrient Cycling and Water Quality.  Much of my current work revolves around enhanced management of cover crops as major tools that impact all three of these research areas. Whenever I have the opportunity, I like to work with farmers in developing countries, especially those in Africa, by diagnosing and finding solutions to agricultural problems in the field while collaborating on integrated agricultural development and soils-related issues.

Research Topic Areas

  • Multi-Purpose Cover Crops to Enhance The Environment and Farm Profitability
  • Soil Health & Quality Management for Sustainable Agriculture
  • Profitable and Soil-Health-Building Strategies for Transitioning to Organic Grains
  • Active Organic Matter Test to Help Assess Soil Health
  • Environmental Impacts of Management Intensive Grazing Based Dairy Farms
  • Sulfur Fertility to Enhance Yields and Protein Quality of Grain Legumes
  • Soil and Nutrient Management
  • Regenerative African Small Holder Farming