Agronomy DVANCES I N VOLUME 73 Advisory Board Martin Alexander Ronald Phillips Cornell University University of Minnesota Kenneth J Frey Larry P Wilding Iowa State University Texas A&M University Prepared in cooperation with the American Society of Agronomy Monographs Committee John Bartels Jerry M Bigham Jerry L Hatfield David M Kral Diane E Stott, Chairman Linda S Lee David Miller Matthew J Morra John E Rechcigl Donald C Reicosky Wayne F Robarge Dennis E Rolston Richard Shibles Jeffrey Volenec Agronomy DVANCES IN VOLUME 73 Edited by Donald L Sparks Department of Plant and Soil Sciences University of Delaware Newark, Delaware San Diego San Francisco New York Boston London Sydney Tokyo This book is printed on acid-free paper Copyright C ∞ 2001 by ACADEMIC PRESS 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 The appearance of the code at the bottom of the first page of a chapter in this book indicates the Publisher’s consent that copies of the chapter may be made for personal or internal use of specific clients This consent is given on the condition, however, that the copier pay the stated per copy fee through the Copyright Clearance Center, Inc (222 Rosewood Drive, Danvers, Massachusetts 01923), for copying beyond that permitted by Sections 107 or 108 of the U.S Copyright Law This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale Copy fees for pre-2001 chapters are as shown on the title pages If no fee code appears on the title page, the copy fee is the same as for current chapters 0065-2113/01 $35.00 Explicit permission from Academic Press is not required to reproduce a maximum of two figures or tables from an Academic Press chapter in another scientific or research publication provided that the material has not been credited to another source and that full credit to the Academic Press chapter is given Academic Press A Harcourt Science and Technology Company 525 B Street, Suite 1900, San Diego, California 92101-4495, USA http://www.academicpress.com Academic Press Harcourt Place, 32 Jamestown Road, London NW1 7BY, UK http://www.academicpress.com International Standard Book Number: 0-12-000773-8 PRINTED IN THE UNITED STATES OF AMERICA 01 02 03 04 05 06 SB Contents CONTRIBUTORS PREFACE vii ix INTERACTIONS AMONG ROOT-INHABITING FUNGI AND THEIR IMPLICATIONS FOR BIOLOGICAL CONTROL OF ROOT PATHOGENS David M Sylvia and Dan O Chellemi I II III IV V Introduction Functional Diversity in the Root Zone Interactions among Root-Inhabiting Fungi Opportunities for Pest Control Research Priorities References 13 17 21 24 DWARFING GENES IN PLANT IMPROVEMENT S C K Milach and L C Federizzi I II III IV V VI VII Introduction The Biochemical Basis of the Dwarf Phenotype Dwarfing Genes and Their Use for Breeding Breeding Challenges and Varieties Developed Pleiotropic Effects of Dwarfing Genes Molecular Mapping of Dwarfing Genes Concluding Remarks References 36 38 43 45 48 51 55 56 A REVIEW OF THE EFFECT OF N FERTILIZER TYPE ON GASEOUS EMISSIONS Roland Harrison and J Webb I Introduction II The Processes Controlling Emissions of Nitrogen Gases from Fertilizers III Measurements of Ammonia Emission Following Nitrogen Fertilizer Application v 67 69 78 vi CONTENTS IV Ammonia Emission Factors for Nitrogen Fertilizers V Measurements of Nitrous Oxide Emissions Following Nitrogen Fertilizer Applications VI Nitrous Oxide Emission Factors for Nitrogen Fertilizers VII Nitric Oxide Emissions from Nitrogen Fertilizers VIII Summary and Conclusions References 88 90 97 99 99 103 RHIZOBIA IN THE FIELD N Amarger I II III IV V VI Introduction Diversity in Rhizobia Rhizobium Systematics Natural Populations of Rhizobia Introduction of Rhizobia into Soil Concluding Remarks References 110 112 123 129 143 147 148 INDEX 169 Contributors Numbers in parentheses indicate the pages on which the authors’ contributions begin N AMARGER (109), Laboratoire de Microbiologie des Sols, Institut National de la Recherche Agronomique, 21065 Dijon, France DAN O CHELLEMI (1), USDA, ARS, Horticultural Research Laboratory, Ft Pierce, Florida 34945 L C FEDERIZZI (35), Universidade Federal Rio Grande Sul, Faculdade de Agronomia, Departamento de Plantas de Lavoura, Porto Alegre, Brazil ROLAND HARRISON (65), ADAS Consulting Ltd., ADAS Boxworth, Boxworth, Cambridge CB3 8NN, United Kingdom S C K MILACH (35), Universidade Federal Rio Grande Sul, Faculdade de Agronomia, Departamento de Plantas de Lavoura, Porto Alegre, Brazil DAVID M SYLVIA (1), Soil and Water Science Department, University of Florida, Gainesville, Florida 32611 J WEBB (65), ADAS Consulting Ltd., ADAS Wolverhampton, Wolverhampton WV6 8TQ, United Kingdom vii This Page Intentionally Left Blank Preface Volume 73 contains four excellent chapters on contemporary and important topics in the agronomic sciences Chapter is a thoughtful review of interactions among root-inhabiting fungi and their implications for biological control of root pathogens The fungi are defined, their distribution and abundance are discussed, and their role in agroecosystems is presented Chapter discusses advances in the role of dwarfing genes in plant improvement Emphasis is placed on breeding and genetics aspects Chapter covers a topic that is of great environmental interest— the effect of nitrogen fertilizers on gaseous emissions Processes controlling and measurements of emissions of nitrogen gases are fully discussed Chapter is a comprehensive review of Rhizobia, including diversity, systematics, natural populations, and field introduction of Rhizobia I thank the authors for their first-rate reviews DONALD L SPARKS ix ... availability in the plant host (Larkin et al., 1995), which results in a reduction in plant vigor and decline in plant health Infection by subclinical pathogens may predispose plants to injury SYLVIA... eliminates the need to obtain and manage information regarding pest biology and their population parameters in the field, thus simplifying the decision-making process Determination of cropping... ecosystem) Subclinical pathogens can also initiate processes leading to the ROOT-INHABITING FUNGI breakdown of plant tissue and recycling of carbon in the soil, as they are present in root tissue