This well-reviewed and vigorous series presents research summaries on aspects of soil science which are as diverse as the subject itself, and range through physical, chemical and biological approaches to the study of soils. Volume 16 contains articles dealing with the role of phosphorus in soil, modeling of chemical absorption in soils, tests to determine nutrient availability and element toxicity in soils, the effects of sewage sludge on soil microbes, and methods to estimate soil water retention based on physical properties of soil.