B. Davis - The Soil

Sarah A. Corbet

S. M. Walters, Sc. D., V.M.H.

Prof. Richard West, Sc. D., F.R.S., F.G.S.

David Streeter, FIBiol

The aim of this series is to interest the general reader in the wildlife of Britain by recapturing the enquiring spirit of the old naturalists. The editors believe that the natural pride of the British public in the native flora and fauna, to which must be added concern for their conservation, is best fostered by maintaining a high standard of accuracy combined with clarity of exposition in presenting the results of modern scientific research.

We are all familiar with the plants and animals with which we share the world above the soil surface. We are much less familiar with the inhabitants and processes in the ubiquitous but inaccessible world of the soil. The organisms in this hidden world are often microscopic, small enough to live in the maze of narrow pores, and are concealed by the opaque matrix in which they live. Taxonomic difficulties add a further barrier to exploration. The Soil is an account of the soil as a living system, in which moles, minerals, molecules and microbes interact with vegetation, under the influence of climate and man.

The soil, the earths skin, has been scarred, peeled off or incurably bruised over much of Britain. It is all too easy for heavy machinery to destroy in minutes a soil profile that has taken centuries to develop. Perhaps this book will help us to appreciate those precious sites where its structure remains intact. It also shows how, if compaction can be avoided, heavy machinery can have a positive role in the large-scale restoration of soil capable of supporting vegetation on mine or industrial waste.

Processes in the soil matter to farmers and gardeners, moles and oak trees. To understand them is a necessity for agronomists, an aspiration of ecologists, and a pleasure for others. Many policy decisions on agriculture and conservation depend on the ability to understand and manipulate soil processes. This is an area where informed public opinion has an important part to play in moulding public policy. Those who read this book will be in a better position to understand some of the more controversial aspects of mans impact on the soil.

Research has advanced on many fronts since Sir John Russell wrote The World of the Soil in this series in 1957. Until now many of those advances have been accessible only to specialists. The authors of this book are in a unique position to introduce us to this new material and to provide an exceptional guide to the ecosystem we tread on every day. It is a credit to the subject that it has advanced far enough in 34 years to merit this new approach, and a credit to the series that it has lived long enough to include this second book.

Soil science came of age in Britain with the publication in 1912 of the first edition of E. J. Russells Soil Conditions and Plant Growth. Forty-five years later, after retiring as director of Rothamsted Experimental Station, Sir John Russell published The World of the Soil in the New Naturalist series to bring the burgeoning subject to a wider audience. Fifty years ago he wrote in his preface, this book would have been much easier to write than it has been today. Enough was then known about the wonders of the soil to show that deeper mysteries lay beyond. The facts gleaned were simple, the generalisations were broad and easily comprehendedNow it is all very different. Vast numbers of learned memoirs have been written about [the subject]. If this statement were true then, how much more so today. The subject has continued to grow in breadth as well as depth with several international journals on soil biology starting since 1957 and a string of published symposia. Soil Conditions and Plant Growth, revised by E.W.Russell and now edited by A. Wild, is in its 11th edition (1988), and is still a standard reference work.

With growth has come increasing specialization in soil physics, pedology, soil biology, microbiology and applied aspects, such as agriculture and land restoration. The student and professional scientist is now well supplied with monographs on all these topics but there is increasing need to see the world of the soil as a whole; to appreciate the complex and delicate structure of this thin skin on the earths surface, the activities of microorganisms in the cycles of decay and renewal, the interwoven lives of animals and plants below and above the soil surface, and mans ability to use or abuse this vital resource. It is difficult to do justice to this broad spectrum, and we have had to be selective in our coverage. We have tried to illuminate a wide range of themes which interest us and which we thought would interest the non-specialist reader. Inevitably, this selection leaves many gaps but if we succeed in whetting an appetite for more information we will be well satisfied.

We have tried to be up to date in concepts and discoveries but, even while preparing the book, the agricultural scene has changed radically. To increase productivity has ceased to be the driving force behind so much of the research on soils that has marked the past 50 years. Crops, however, are just one expression of a soils potential: to create and manage diverse ecosystems is no less a challenge; amongst other things, it entails research on reducing soil fertility.

Each section of the book has been read and criticized among ourselves but, in addition, comments have been obtained from outside experts on particular topics: micro-arthropods M. Luxton, woodlice P. T. Harding, millipedes and centipedes R. E. Jones, spiders E. Duffey, ants T. J. King, other insects R. C. Welch, earthworms B. M. Gerard, nematodes K. Evans, snails and slugs B. Eversham, agriculture B. G. Davies, land restoration S. G. McRae. We are most grateful to all these, and hope to have avoided errors even if we have not presented a topic in the way they would have done.

The sources of illustrations are given with the captions and we would like to thank the following for providing photographs: J.M. Anderson, T. Bauer, Brooms Barn Experimental Station, A.F. Brown, G.P. Buckley, J. Day, B. Dickerson, K. Evans, R. Evans, R.D. Finlay, Frank Lane Picture Agency Ltd, J.A. Grant, Christine Hepper, Dick Jones, T.P. McGonigle, S.G. McRae, R.H. Marrs, J. Miles, National Museum of Wales, J.A. Thomas and T.C.E. Wells. S.V. Green and R.C. Welch kindly made original drawings of snails, woodlice and beetles. were drawn by Paul Joyce. C.A. Howes generously provided original data on mole distributions.

We gratefully acknowledge the kind permission of the following journals and institutes to reproduce copyright illustrations: Pedobiologia ().

Finally, I should like to thank K. Mellanby for his encouragement in writing this book (B.N.K.D.).

U NITS OF MEASUREMENT

Science now uses metric units almost exclusively but it is often easier for many people to visualize an acre rather than a hectare, or to appreciate altitude in feet rather than metres. We have therefore given both in many instances, especially when dealing with historical data. In some cases, English units have become disused except by a few but it would be inappropriate to quote wheat yields in the Middle Ages in anything except hundredweights.