This 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, the modelling 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 for estimating soil water retention based on the physical properties of soil. This monograph on soil science, agriculture, agronomy and soils is intended for soil scientists, agronomists, environmental managers, soil chemists, soil geologists and agricultural engineers.