It is becoming more relevant to explore soil biological processes in terms of their contribution to soil fertility. This book presents a comprehensive scientific overview of the components and processes that underpin the biological characteristics of soil fertility. It highlights the enormous diversity of life in soil and the resulting effects that management of land can have on the contribution of this diverse community to soil fertility in an agricultural context.
The success of shifting cultivation systems developed by subsistence farmers testifies to the resilience of the "natural" soil-plant ecosystems to recover from the offtake of nutrients in crops and loss of soil struc ture. By contrast, the development of intensive cropping systems requires large inputs especially of nitrogen, together with phosphorus, sulphur and other essential elements in order to maintain the nutrient levels needed for abundant crop yields. As Dr. Cooke ably pointed out in his introductory lecture, the dis coveries and experiments of the 19th century encouraged farmers in temperate zones to rely greatly on chemical fertilizers supplements. However, the work of Charles Da{win on soil mixing by earthworms and the discovery by Hellriegel and Wilfarth in 1886 that the nodules on legume roots contain colonies of symbiotic bacteria able to "capture" atmospheric nitrogen molecules to the benefit of the host plant heralded a growing realization of the importance of soil biota in fertility studies. Biological fixation of nitrogen has been the theme of many meetings and publi~ations hitherto but at this Conference, convened on the delightful campus of Reading University, attention was mainly focussed on other biological processes in soil fertility. These Proceedings record the dominant themes and include six keynote addresses delivered at plenary sessions and seven introductory lectures to paper reading sessions by invited individuals plus 22 of the proferred papers, in six sections as tabled in the contents list.
It has long been recognized that soil organic matter is the key to soil fertility. As a nutrient store it gradually provides essential elements which the soil cannot retain for long in inorganic form. It buffers growing plants against sudden changes in their chemical environment and preserves moisture in times of drought. It keeps the soil in a friable, easily penetrated physical condition, well-aerated and free draining, providing young seedlings with an excellent medium for growth. But it has another property, the nature and extent of which have been the subject of argu ment and controversy ever since scientists began to study the soil, and that is its ability to affect growth directly, other than by providing nutrient elements. Any one wishing to learn about these effects has been faced with a daunting mass of literature, some confusing, often contradictory, and spread through a multitude of journals. Individual aspects have been covered from time to time in reviews but there has obviously been a need for a modern authoritative text book dealing with the many facets of this subject, so the publication of this volume is timely. The editors and authors are all specialists in their fields, fully familiar with the com plex nature of soil organic matter and with the particular difficulties arising in any study of its properties. Where controversies exist they have presented all sides of the argument and have highlighted areas where further work is badly needed.
Annotation. Successful agroforestry requires an understanding of the complex relationship between trees, crops and soils. This book provides a review of both economic and biophysical aspects of soil use and research in agroforestry, with an emphasis on nutrient-poor forest and savanna soils. Key topics covered include the economics of soil fertility management, cycling of water, nutrients and organic matter, soil structure, and soil biological processes. The book combines synthetic overviews of research results and a review of methods used in research.From the foreword: 2The book is written within a particular context - soil fertility development under agroforestry. At first this may seem very specific and thus limited in appeal and application. But over the last decade or so agroforestry research has been one of the most influential in developing new insights into soil biology and fertility and thus provides a very suitable framework for review of progress. Furthermore the influence of trees on soil is profound and of significance beyond agroforestry systems, so the book is likely to be of interest in the wider spheres of agriculture, forestry and ecological sciences.3 Mike Swift, TSBF, Nairobi, Kenya.
Written by leading experts in their respective fields, Principles and Applications of Soil Microbiology 3e, provides a comprehensive, balanced introduction to soil microbiology, and captures the rapid advances in the field such as recent discoveries regarding habitats and organisms, microbially mediated transformations, and applied environmental topics. Carefully edited for ease of reading, it aids users by providing an excellent multi-authored reference, the type of book that is continually used in the field. Background information is provided in the first part of the book for ease of comprehension. The following chapters then describe such fundamental topics as soil environment and microbial processes, microbial groups and their interactions, and thoroughly addresses critical nutrient cycles and important environmental and agricultural applications. An excellent textbook and desk reference, Principles and Applications of Soil Microbiology, 3e, provides readers with broad, foundational coverage of the vast array of microorganisms that live in soil and the major biogeochemical processes they control. Soil scientists, environmental scientists, and others, including soil health and conservation specialists, will find this material invaluable for understanding the amazingly diverse world of soil microbiology, managing agricultural and environmental systems, and formulating environmental policy. - Includes discussion of major microbial methods, embedded within topical chapters - Includes information boxes and case studies throughout the text to illustrate major concepts and connect fundamental knowledge with potential applications - Study questions at the end of each chapter allow readers to evaluate their understanding of the materials
In this handbook methods are given to determine soil characteristics, organic matter compounds, phosphorus in soil, nitrogen fixation, soil solution sampling, plant nutrient uptake and the nitrogen availability
Forward. A call for integrated soil fertility management in Africa. Introduction. ISFM and the African farmer. Part I. The principles of ISFM: ISFM as a strategic goal, Fertilizer management within ISFM, Agro-minerals in ISFM, Organic resource management, ISFM, soil biota and soil health. Part II. ISFM practices: ISFM products and fields practices, ISFM practice in drylands, ISFM practice in savannas and woodlands, ISFM practice in the humid forest zone, Conservation Agriculture. Part III. The process of implementing ISFM: soil fertility diagnosis, soil fertility management advice, Dissemination of ISFM technologies, Designing an ISFM adoption project, ISFM at farm and landscape scales. Part IV. The social dimensions of ISFM: The role of ISFM in gender empowerment, ISFM and household nutrition, Capacity building in ISFM, ISFM in the policy arena, Marketing support for ISFM, Advancing ISFM in Africa. Appendices: Mineral nutrient contents of some common organic resources.
