$. V O L U Ms sE . .- Advisory Board Cornell University Eugene J. Kamprath North Carolina State University Kenneth J. Frey Larry P. Wilding Iowa State University Texas A&M University Martin Alexander Prepared in cooperation with the American Society of Agronomy Monographs Cornmiltee M.A. Tabatabai, Chairman S. H. Anderson P. S. Baenziger W. T. Frankenberger, Jr. D. M. Kral S. E. Lingle R. J. Luxmoore G . A. Peterson S. R. Yaks D V A N C E S I N onomy VOLUME 55 Edited by Donald L. Sparks Department of Plant and Soil Sciences University of Delaware Newark, Delaware ACADEMIC PRESS SanDiego NewYork Boston London Sydney Tokyo Toronto This book is printed on acid-free [email protected] Copyright 0 1995 by ACADEMIC PRESS,INC. All Rights Reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Academic Press, Inc. A Division of Harcourt Brace & Company 525 B Street, Suite 1900, San Diego, California 92101-4495 United Kingdom Edition published by Academic Press Limited 24-28 Oval Road, London NWl 7DX International Standard Serial Number: 0065-21 13 International Standard Book Number: 0-12-OOO755-X PRINTEDIN THE UNlTED STATESOF AMERICA 95 96 9 7 9 8 99 0 0 B B 9 8 7 6 5 4 3 2 1 Contents CONTRIBUI-ORS. ............................................. iX PREFACE................................................... xi SYNCHROTRON X-RAYTECHNIQUES IN SOIL,PLANT, AND ENVIRONMENTAL RESEARCH Darrell G . Schulze and Paul M. Bertsch 1. Introduction. ..................................................... 11. Synchrotron X-Ray Sources and Synchrotron Light.. .................. III. Synchrotron X-Ray Techniques and Their Applications................. Iv. Accessing Synchrotron Facilities. .................................... References ....................................................... 2 3 1s 54 57 GEOGRAPHIC INFORMATION SYSTEMS IN AGRONOMY G. W. Petersen, J. C. Bell, K. McSweeney, G. A. Nielsen, and P. C. Robert I. Introduction. ..................................................... II. Overview of GIS Technology. ...................................... III. Remote Sensing. .................................................. Iv. Terrain Analysis and Soil