Soil scientists apply themselves on the one hand to fundamental studies of soil properties and processes and on the other to the application of such information to the solution of problems, for example; crop production; pollution control; and the reduction of soil degradation. Progress in soil science often arises from the interplay of workers approaching the soil and its understanding from these two viewpoints. Soil science as a subject may be approached through many disciplines - biology, chemistry, geology, physics, geography, mathematics, microbiology and forestry.
Traditionally soil science has been studied under a number of broad headings and a professional soil scientist will be expected to have a working knowledge of most, if not all, of these. It is however usual to specialise eventually in one or two of these categories.
The subject can be divided generally into the following areas:-
- Pedology - the study of soil as a natural body; its development, distribution, properties and processes and classification.
- Soil Physics - soil water relations, soil as an environment for plant growth, soil as a filter for applied materials such as pesticide, sewage sludge and animal slurries, and soil structure and strength in relation to cultivations, susceptibility to erosion and its use in special situations (e.g. for establishing sports turf or embankments).
- Soil Chemistry - the understanding of the nature of soil constituents and their interactions based upon organic, inorganic and physical chemistry, soil fertility, crop nutrition, soil organic matter and the behaviour and retention of added materials such as pesticides and radio-nucleotides.
- Soil Biology - an understanding of the biology of soil systems, the microbial ecology of soils and soil-plant relationships, microbial processes in soils in relation to the provision of the needs of plants and the management of applied pollutants, especially pesticides. An understanding of the soil biology is important not only in the maintenance of a satisfactory environment for plant growth but also in the restoration of soils following activities such as mining or contamination from other sources.
- Soil Mineralogy - the identification and analysis of minerals, and their significance in soil structure plant nutrition and the soils resilience to pollution effects.
- Soil Management - an increasingly important component of both teaching and employment in soil science is the understanding of how best to manage soil. This may involve the identification of the range of alternatives and the selection of appropriate management strategies for different land use options. These options can include cultivations, drainage, irrigation, assessment of potential soil structure degradation, land reclamation, land restoration and the prevention of soil erosion and damage.
- Soil Survey and Land Evaluation - mapping the distribution of soils, recording soil properties and using this and allied information to evaluate the land's suitability for a range of uses. This information may be used in the development of land management strategies or in the resolution of planning conflicts.
The above list illustrates that soil science can be regarded as a truly "integrated science", affording soil scientists the opportunity to maintain a professional interest in several scientific disciplines. This broad background means that soil scientists can move easily into other areas where their skills can also be applied.