Environmental Soil Biology

Transcription

1 Environmental Soil Biology

2 Tertiary Level Biology A series covering selected areas of biology at advanced undergraduate level. While designed specifically for course options at this level within Universities and Polytechnics, the series will be of great value to specialists and research workers in other fields who require knowledge of the essentials of a subject. Recent titles in the series: Social Behaviour in Mammals Seabird Ecology The Biochemistry of Energy Utilization in Plants The Behavioural Ecology of Ants Anaerobic Bacteria Evolutionary Principles Seabird Ecology An Introduction to Marine Science (2nd edn.) Seed Dormancy and Germination Plant Molecular Biology (2nd edn.) Polar Ecology The Estuarine Ecosystem (2nd edn.) Soil Biology Photosynthesis The Cytoskeleton and Cell Motility Waterfowl Ecology Tropical Rain Forest Ecology (2nd edn.) Fish Ecology Solute Transport in Plants Human Evolution Principles and Techniques of Contemporary Taxonomy Biology of Fishes (2nd edn.) Poole Furness and Monaghan Dennis Sudd and Franks Holland, Knapp and Shoesmith Calow Furness and Monaghan Meadows and Campbell Bradbeer Grierson and Covey Stonehouse McLusky Wood Gregory Preston, King and Hyams Owen and Black Mabberley Wootton Flowers and Yeo Bilsborough Quicke Bone, Marshall and Blaxter

3 Tertiary Level Biology Environmental Soil Biology Second Edition MARTINWOOD Reader in Soil Ecology Department of Soil Science The University of Reading SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.

4 First edition 1989 Second edition Springer Science+Business Media Dordrecht Origina11y published by Chapman & Hall in 1995 Softcover reprint ofthe hardcover 2nd edition 1995 Typeset in 1O/12pt Times by Cambrian Typesetters, Frimley, Surrey ISBN ISBN (ebook) DOI / Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the UK Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored, or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publishers at the Glasgow address printed on this page. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. A catalogue record for this book is available from the British Library Library of Congress Catalog Card Number: Printed on permanent acid-free text paper, manufactured in accordance with ANSIINISO Z (Permanence of Paper)

5 Preface Soil biology is a theme which runs through many of the major areas of modern science; the subject encompasses global issues concerning the environment, conservation and food production, and the tools used for its study range from molecular biology to the common spade. The aim of this book, which has been largely re-written since the first edition of Soil Biology (1989), is to provide an account of the subject for undergraduate and postgraduate students of environmental science and related subjects. The first part of the book provides an introduction to soils, its inhabitants, and their activities. The second part covers the influence of man on the natural cycles of soil. Topics such as acid rain and nitrogen fertilisers are considered alongside pesticides and genetically modified organisms. A new final chapter has been added which considers how, as we move towards the next millennium, we can apply the concept of sustainability to issues such as global climate change and farming systems. Much of the work for this book was carried out whilst I was on sabbatical in New Zealand; I am grateful to the staff of the Department of Soil Science at Lincoln University for their stimulating company and hospitality, and to the British Council and the Stapledon Memorial Trust for providing financial assistance. Finally, thanks not only to Diane, Rebecca and Jennifer, but also to William and to Donald. M.W.

6 Contents 1 Soil as a habitat for organisms Introduction The soil environment Inorganic material Organic matter Soil structure Soil moisture Soil atmosphere Temperature Summary 12 2 Life in the soil Introduction Microbial biomass The soil inhabitants Functional groups of organisms Viruses Bacteria and actinomycetes Fungi Cyanobacteria and algae Protozoa Nematodes Earthworms Arthropods Molluscs Other animals Plant roots The rhizosphere Plant root pathogens Legume root nodules Actinorhizas Agrobacterium Mycorrhizas Root-knot nematodes Summary 40 3 Biological processes in soil Introduction What do organisms require for life? Energy and carbon Nitrogen Selected biochemical processes Nitrogen fixation Nitrification 47

7 viii CONTENTS Denitrification Sulphur oxidation Reduction of inorganic sulphur 3.4 Soil enzymes Carbohydrases Esterases Proteases and amidases Oxidoreductases 3.5 Sources of substrates for heterotrophs Amounts of substrates Survival strategies 3.6 Substrate quality Elemental composition 3.7 Microbial biomass and nutrient cycling 3.8 Summary Soil formation and development 4.1 Introduction 4.2 Pedogenesis 4.3 Weathering of rock 4.4 Organic matter Organic matter turnover Effects of seasonal change Effects of soil conditions Role of earthworms Role of termites Food webs 4.5 Profile development Role of microorganisms Role of meso fauna and macrofauna Role of plant roots Role of vegetation 4.6 The influence of man Environmental issues 5.1 Introduction 5.2 Acidification Aluminium toxicity Protected microsites Acid rain 5.3 Salinity 5.4 Heavy metals 5.5 Chernobyl and radioactivity 5.6 Nitrate leaching Inhibitors of N transformations 5.7 Pesticides Side effects Recalcitrant compounds 5.8 Introduced organisms Introductions of non-engineered organisms Genetically modified organisms Risk assessment

8 CONTENTS IX 6 Soil biology - into the next millennium 6.1 Introduction 6.2 Sustain ability - so what's new? 6.3 Environmental quality Use of non-renewable resources Soil quality Soils, subsoils and water quality 6.4 Soils and global climate change 6.5 Biodiversity Effects of management practice Soil resilience Ecotoxicology 6.6 Sustainable agricultural systems 6.7 Man and the Earth References and further reading Index