Elements of the Nature and Properties of Soils

About our authors Ray R. Weil is a professor of soil science at the University of Maryland. He has previously served in the Peace Corps in Ethiopia, managed a 500-acre organic farm in North Carolina, and been a lecturer at the University of Malawi. Dr. Weil is an international leader in sustainable agricultural systems in both developed and developing countries. Published in more than 85 scientific journals and in eight books, Dr. Weil focuses his research on cover crops and organic matter management for enhanced soil quality and nutrient cycling for water quality and sustainability. His research lab developed analytical methods for soil microbial biomass and active soil C that have been adopted by the USDA/NRCS and are used in ecosystem studies worldwide. His contributions to improved cropping systems and soil management have been put into practice on farms large and small. At the University of Maryland, Dr. Weil teaches undergraduate and graduate classes in soil science and sustainable agriculture. He has taught more than 7,000 students, addressed more than 5,000 farmers and farm advisors at meetings and field days, and helped train hundreds of researchers and managers in various companies and organizations. Weil is a fellow of both the Soil Science Society of America and the American Society of Agronomy. He has twice been awarded a Fulbright fellowship to support his work in developing countries. The synergism between Dr. Weil's teaching and research and his ecological approach to soil science have found expression in various editions of this textbook since 1995. Dr. Weil holds degrees from Michigan State University, Purdue University and Virginia Tech. Nyle C. Brady (late), a native of Colorado, served on the Cornell University faculty from 1947 to 1973, and in 1952 co-authored the world's most widely used college textbook on soil science. He was head of Cornell's Department of Agronomy from 1955 to 1963 and director of their Agricultural Experiment Station from 1965 to 1973. He was also associate dean of the New York State College of Agriculture and Life Sciences from 1970 to 1973. Dr. Brady also contributed to scientific development nationally and internationally. He was Director of Science and Education of the US Department of Agriculture (1963 to 1965), Director General of the International Rice Research Institute in the Philippines (1973 to 1981), Senior Assistant Administrator for Science and Technology of the US Agency for International Development (1981 to 1989), and a full-time senior consultant for collaborative research and development programs of the World Bank and the UN Development Program (1990 to 1994). Dr. Brady graduated from Brigham Young University in 1941 with a bachelor's degree in chemistry. In 1947 he received his PhD in soil science from the University of North Carolina. Dr. Brady passed away in 2015 at the age of 95.

1. The Soils Around Us
2. Formation of Soils from Parent Materials
3. Soil Classification
4. Soil Architecture and Physical Properties
5. Soil Water: Characteristics and Behavior
6. Soil and the Hydrologic Cycle
7. Soil Aeration and Temperature
8. The Colloidal Fraction: Seat of Soil Chemical and Physical Activity
9. Soil Acidity, Alkalinity, Salinity, and Sodicity
10. Organisms and Ecology of the Soil
11. Soil Organic Matter
12. Nutrient Cycles and Soil Fertility
13. Practical Nutrient Management
14. Soil Erosion and Its Control
15. Soils and Chemical Pollution