A D V A N C E S IN AGRONOMY VOLUME 17 CONTRIBUTORS TO THIS VOLUME MARKA. BARMORE HOWARD J. BROOKS A. J. CLINE ROUSES. FARNHAM GEORGET. FELBECK, JR. H. R. FINNEY HAROLD W. FOCLE H. J. GORZ ERHARDT R. HEHN DONAL D. JOHNSON JOHN W. MCKAY LEWISR. NELSON W. K. SMITH ADVANCES IN AGRONOMY Prepared under the Auspices of the AMEZICANSOCETYOF AGRONOMY VOLUME 17 Edited by A. G. NORMAN The University of Michigan, Ann Arbor, Michigan ADVISORY BOARD H. D. MORRIS F. L. PATTERSON K. T. PAYNE C. 0. GARDNER C. L. HAMILTON W. P. MARTIN 1965 @ ACADEMIC PRESS New York and London COPYRIGHT @ 1965, BY ACADEMICPRESSINC. ALL RIGHTS RESERVED. NO PART OF THIS BOOK MAY BE REPRODUCED IN ANY FORM, BY PHOTOSTAT, MICROFILM, OR ANY OTHER MEANS, WITHOUT WRITTEN PERMISSION FROM THE PUBLISHERS. ACADEMIC PRESS INC. 111Fifth Avenue, New York, New York 10003 United Kingdom Edition published by ACADEMIC PRESS INC. (LONDON) LTD. Berkeley Square House, London W.1 LIBRARYOF CONGRESSCATALOG CARDNUMBER: 50-5598 PRINTED IN THE UNITED STATES OF AMERICA CONTRIBUTORS TO VOLUME 17 Numbers in parentheses indicate the pages on which the authors’ contributions begin. BARMORE, MARKA. ( G ) ,Chemist, Western Wheat Quality Laboratory, Crops Research Division, Agricultural Research Service, United States Department of Agriculture, Washington State University, Pullman, Washington BROOKS,HOWARDJ . (283). Research Horticulturist, Crops Research Division, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland CLINE,A. J . (233), Senior Soil Correlator, Soil Conservation Service, Fort Collins, Colorado FARNHAM, ROUSES. ( 115),Assistant Professor, Department of Soil Science, University of Minnesota, Institute of Agriculture, St. Paul, Minnesota FELBECK, GEORGE T., JR. (327), Associate Professor, Department of Agricultural Chemistry, University of Rhode Island, Kingston, Rhode Island FINNEY,H. R. (115), Research Assistant, Department of Soil Science, University of Minnesota, lnstitute of Agriculture, St. Paul, Minnesota FOGLE,HAROLD W. (283), Research Horticulturist, Crops Research Diukion, Agricultural Research Service, United States Department of Agriculture, Beltsville, Mayland GORZ,H. J. (la), Research Geneticist, Crops Researoh Division, Agricultural Research Service, United States Department of Agriculture, and Professor, Department of Agronomy, University of Nebraska, Lincoln,Nebraska HEHN,E R H A ~R.T (S), Head, Department of Plant and SOU Science, Montana State College, Bozeman, Montana DONAL D. (233), Professor of Soils, Department of Agronomy, Colorado State University, Fort Collins, Colorado JOHNSON, MCKAY,JOHN W. (283),Research Horticulturist, Crops Research Division, Agricultural Research Seroice, United States Department of Agriculture, Beltsville, Maryland V vi CONTRIBUTORS NELSON, LEWISB. ( l ) ,Manager,
[email protected] of Agricultural and Chemical Development, Tennessee Valley Authority, Wilson Dam, Alabama SMITH,W. K. (la), Professor, Departments of Agronomy and Genetics, and Agent, Crops Research Division, Agricultural Research Service, United States Department of Agriculture, University of Wisconsin, Madison, Wisconsin PREFACE In all countries of the world in which scientific agriculture is practiced, crop production and acre yields have increased markedly in the last two decades. Fertilizers, efficiently used, have contributed substantially to this progress. World-wide fertilizer consumption is steadily rising. As technical and economic resources are acquired in areas now less favored, so is it to*be expected that striking changes in