The study of soils is increasingly important due to growing demands on soils by rapidly expanding populations. Volume 15 of Advances in Soil Sciences is a mixed-topic volume in this series; consisting of five critical review articles: 1. VA Mycorrhizae as modifiers of soil fertility (J.M. Barea, Estacion Experimental del Zaidin, Granada, Spain) 2. Argillic horizons in modern loess soils in an ustic soil moisture regime? (A. Bronger, University of Kiel, FRG) 3. Myths and scientific realities of agroforestry as a strategy for sustaining management of soils in the tropics (R. Lal, Ohio State University, Columbus, OH) 4. Land evaluation: from intuition to quantification (C.A. van Diepen et al. Winand Staring Center for Integrated Land, Soil and Water Research, Wageningen, The Netherlands) 5. Crop residue management (R. Prasad, Indian Agri- cultural Research Institute, New Delhi, India)
Bobby Alton Stewart, Ph.D., is Distinguished Professor of Agriculture and Director of the Dryland Agriculture Institute at West Texas A&M University, Canyon, Texas. Prior to joining West Texas A&M University in 1993, he was with the USDA Agricultural Research Service in Oklahoma, Colorado, and Texas. He served as Director of the USDA Conservation and Production Laboratory at Bushland, Texas from 1968 to 1993.