Soil Biology Primer
A 54 pg. booklet available from the Soil and Water Conservation Society.
Environmental Literacy Council – Soil
Descriptions of soils and soil ecosystems and links to U.S. and international data.
Sustainable Soil Management
Informational guide produced by FAO (Food and Agriculture Organization of the United Nations).
Introduction to soil quality maintained by USDA-NRCS.
Soil Quality Indicator Sheets
Illustrated fact sheets prepared by USDA-NRCS. Nineteen titles available (in .pdf format) including topics such as Organic Matter, Aggregate Stability, and Soil Biodiversity.