This book is intended for anyone interested in the living aspects of soils – especially land managers, gardeners and students
Land managers can maintain a biologically diverse and active soil through a three-step process:
STEP 1. Become aware of the fundamental importance of soil organisms.
STEP 2. Understand how biological processes in soil are influenced by changes in the soil environment (e.g. by land management practices or by changes in season or climate).
STEP 3. Learn how to manage soil to enhance the benefits provided by many soil organisms (the appropriate practices will depend on local conditions, including soil type).
This book deals principally with Steps 1 and 2. It is written with a broad focus and includes discussion of soil biological process in natural ecosystems as well as managed ecosystems (e.g. agriculture, horticulture, viticulture, agroforestry, forestry and restoration of disturbed land such as mine rehabilitation or road verges). An understanding of biological processes that occur in natural ecosystems gives essential background for predicting and interpreting what can be achieved in highly managed ecosystems. For example, knowing about biological functions in soil prior to conversion to agriculture or horticulture can help interpret soil issues related to the sustainability of land management practices.
‘Soils are Alive’ summarises scientific knowledge of soil biology that underpins complex interrelationships between biological processes in soil. The activities of soil organisms can be difficult to study, but there is a wealth of investigations that demonstrate the scientific basis of the discipline. I have selected examples from a range of environments to illustrate important concepts, but scientific investigations have not yet delivered complete answers to questions about the roles of many organisms in soil.
The biology of soil organisms introduce in this book is relevant everywhere, from natural or managed productive ecosystems, to land which is undergoing rehabilitation. Although different environments are included in the discussion that follows, the soil biological processes are essentially the same in all of them. A book of this scope and size only skims the surface of knowledge of the discipline of soil biology. Every aspect included in this book has been covered in much greater detail elsewhere within the scientific literature. ‘Soils are Alive’ simply seeks to provide a point from which you can expand your knowledge of soil biology through further investigation.
‘Soils are Alive’ starts by building up a picture of what soils ‘look like’ and the kinds of organisms that call soil ‘home’. This is presented from the viewpoint of soil fertility - you are encouraged to consider 'soil fertility' in the broad context, and the reason for this will be explained. A major focus is an exploration of why and how living organisms are affected by changes in physical and chemical characteristics of soil. The soil environment is continually influenced by many factors. It is a dynamic environment from the perspective of soil organisms. The environmental changes that soil organisms experience are due to natural events as well as intentional events such as farming practices.
Throughout the book, soil organisms are examined from in terms of what they do, how they influence the soil around them, and how they influence plants. Some of the complex interactions that occur between organisms in soil are mentioned and some of the links that occur between biological processes and soil physical and chemical properties are highlighted. Knowledge of soil biology can help in the development of guidelines for identifying sustainable land management practices.
The book is structured so that the scientific basis of what is known about life in soil unfolds in sequence, as does information about the complexity of soil processes. The text can be read without referring to the tables and figures; the data presented illustrate examples of information available in the scientific literature. Additional references are included in the margins for further study.
Many soil biological phenomena that are not well explained scientifically due to their complexity and because the tools needed to investigate them are unavailable or difficult to use. The information presented highlights knowledge gathered over many decades by dedicated soil biologists, and this is why many older references are included. However, it is now a very exciting time for soil biology because new technologies are greatly enhancing the capacity of scientists to study organisms in soil.
In an attempt to demonstrate the inter-relatedness of biological processes in soil, some ideas are deliberately repeated in different contexts.
‘Soils are Alive’ seeks to encourage more questions than answers because the answers are not always simple.
Solutions for sustainable land management have to be based on complete knowledge of soil rather than knowledge of some of its components. The integration of knowledge of soil biology with soil physical, chemical and hydrological information can fill gaps that are often missing. Finally, life in soil is complex, intricate, resilient and delicate, and it has the capacity to restore degraded land when managed appropriately.
‘Soils are Alive’ can be read in conjunction with the website: www.soilhealth.com