Advances in Agronomy continues to be recognized as a leading reference and a first-rate source of the latest and best research in agronomy. As always, the topics covered are varied and exemplary of the panoply of subject matter dealt with by this long-running serial. Volume 69 contains five excellent reviews dealing with crop and soil sciences. Chapter 1 is a comprehensive and timely review of the measurement and interpretation of bulk mass-transfer phenomena for organic compounds in soils. Chapter 2 is an excellent overview of environmental indicators of agroecosystems. In chapter 3, an interesting treatise is presented on plant growth as effected by phosphate solubilizing soil microorganisms. Chapter 4 is a fine review on hydrological factors affecting phosphorus transfer from agricultural soils. The concluding chapter is an excellent discussion of the genetic resources of Cassava Manihot esculenta Crantz.