Soil Science

Soil science is the science that deals with soils as a natural resource. Studies focus on soil formation, classification and mapping, and the physical, chemical and biological properties and fertility of soils as such and in relation to their management for crop production. This definition, adopted by the Canadian Society of Soil Science, is somewhat dated. Soil science has expanded to include the study of soil resources in relation to ecology, climate change, forestry, Quaternary geology, hydrology, watershed management, engineering, archaeology, renewable resource management and land-use planning. Pedology, or the science of the processes that form and affect soil through time and space, has applications to Quaternary history, soil reclamation, acid rain, global change and sustainable development. Biometeorology and remote sensing are closely allied to soil science.

Soil has been studied scientifically for approximately 2 centuries. The major concepts were developed over the past 100 years, following the contributions of Vasily V. Dokuchaev and others in Russia. These scientists demonstrated that soils are natural bodies, developing as a result of environmental factors. Two important concepts have emerged: pedology considers soil as a natural body, placing less emphasis on its immediate use; and edaphology studies soil from the standpoint of crop plants. Pedologists study and classify soil as it occurs in the natural environment; edaphologists consider soil properties as they relate to food and fibre production.

History

In Canada soil has been studied systematically for approximately 100 years. The first work, written by Dominion Chemist Frank T. Shutt and published in 1893, originated from the Experimental Farms Service of the federal Department of Agriculture. During this early period, work on soils was begun at the Ontario Agricultural College (OAC, Department of Agricultural Chemistry; see University of Guelph) and at Macdonald College, McGill (Department of Agricultural Physics). A.J. Galbraith of the OAC initiated soil surveying in 1914. Frank A. Wyatt began soil-survey work in Alberta in 1920, Roy Hansen in Saskatchewan in 1921. Surveys began in BC in 1931; Qué and NS, 1934; NB, 1938; PEI, 1943; NWT, 1944; and Nfld, following its entry into Confederation, in 1949. The early surveys, financed by provincial governments, were conducted through co-operative programs among the federal and provincial departments of agriculture and the universities. Many individuals contributed to the development of soil science in Canada, but its founders were professors Frank A. Wyatt (Alta), A.H. Joel and Roy Hansen (Sask), Joseph H. Ellis (Man) and Gerald N. Ruhnke (Ont). E.S. Archibald, director of the Dominion Experimental Farms Service, played an important role in reviving the soil survey in the 1930s.

Training

Professional education in soil science is offered at major universities in Canada. Saskatchewan, Manitoba and Québec (Laval) have soil-science departments. Other universities offer soil science programs in geography or recently amalgamated departments of renewable resources or earth sciences.

Most universities offering soil-science programs award bachelor's, master's and doctoral degrees. Although there is some variation in the designation of specialization, some of the major areas of study include soil biology, chemistry, physics and fertility; soil classification, genesis, mineralogy and conservation; soil contamination and remediation; land classification; and forest soils. Often specialization occurs only at the postgraduate level. Students require a background in biology, chemistry, mathematics and physics, and also study agronomy, botany, computer science, ecology, economics, English, geology, geomorphology, hydrology, land-use planning, meteorology, microbiology, mineralogy, photogrammetry, remote sensing, resource management, etc. Soil-science education is useful to botanists, plant scientists, civil and agricultural engineers, environmental scientists, land and soil reclamation specialists and Quarternary scientists.

Research

The federal government has a history of conducting research on soil resources and their use, especially Agriculture and Agri-Food Canada, Environment Canada, the National Research Council and Natural Resources Canada. Fundamental research on soils is carried out by universities. Applied research is conducted by the private sector often through partnerships among governments, universities and the private sector. These programs are becoming more common and effective. Areas of major concern include work in such areas as forestry (silviculture, soil stability), mining and petroleum resources (reclamation), industrial sites (soil contamination and reclamation) and landscape ecology. Climate change, carbon dynamics and water management have become demand areas for research. The research conducted in Canada has international recognition and global applications.

The early work carried out by the Department of Soil Science at University of British Columbia on organic matter decomposition led the country in soil microbiology. The University of Alberta's Department of Soil Science carried out innovative research on the management and genesis of gray wooded (gray luvisol) soils. The use of radioactive isotopes in relation to soil fertility and phosphorus was pioneered at the University of Saskatchewan. Study of the effects of application of sewage sludge to soil was initiated at Guelph University. Fundamental research on soil properties relating them to the physical behaviour of soils (eg, correlation of shear strength with the electrochemical properties of clays and forces involved in clay swelling) was carried out at the Macdonald College. Laval University and University of Toronto pioneered forest soil research.

Researchers from Agriculture Canada have taken a leading role in understanding the reclamation and management of solonetzic soils and in studies of soil organic matter, its properties, characteristics and functions in the soil system. Québec researchers were in the forefront of farm drainage for intensive agriculture. Soil scientists from Atlantic Canada have developed management techniques for the important potato industry. The Canada Soil Survey Committee, composed of federal and provincial scientists and university professors, developed a soil-classification system and unique approaches to soil-survey and soil-information databanks. Agencies involved in soil research have developed soil-testing procedures for better crop growth on Canadian soils. This process is on going as new varieties of crops, with different requirements, are steadily being developed or introduced into Canada and management practices continue to evolve. Research efforts focus on soil erosion, salinity and conservation and make use of remote sensing and computer-assisted laboratory and field techniques, computer-assisted information systems, and automatic graphic and cartographic displays.

Applications

Soil research has historically been applied to agriculture, especially to improve crop yields. Research has focused on the nutrients and trace elements essential for plant growth. Knowledge of soil properties has helped to develop irrigation and drainage projects, to promote proper use of fertilizers and pesticides and to explain the effect that soil management has on the resource. The availability of soil surveys for much of the country allows planners to make choices, depending on the capability of soils, among agriculture, forestry, recreation and wildlife uses. Highway engineers are beginning to use soil surveys for siting roadways. Other engineers and planners use soil information for locating septic tank disposal fields, effluent irrigation, urban subdivisions, pipeline and transportation corridors and for regulating and predicting water supply. Increasingly the principles of soil science are being applied to contaminated sites, especially petrochemicals and heavy metals. Through the application of geographic information systems (GISs), linkages between land use, water resources and land management and climate change are being forged to allow policymakers to formulate effective action.

Regional planners make use of soil science in developing plans for municipalities and counties. Land appraisers must know soil productivity to make fair assessments of value. Soil properties and genesis are important in understanding terrestrial ecology and groundwater flow. Knowledge of soil genesis aids better understanding of the events that have taken place during the Quaternary, and soils hold the record of facts important in archaeology. Rangeland managers must take into account the productive potential of soil so that range deterioration will not accelerate. Increasingly, agencies involved with land restoration (eg, mining and petroleum exploration companies) are making use of soil-science principles. Soil scientists are employed by universities, federal and provincial governments and consulting firms, forest companies, mining and petroleum companies, banks, real-estate firms and large corporate farms.

Societies and Institutions

In Canada the recognized society fostering soil science is the Canadian Society of Soil Science (CSSS). The CSSS was founded in 1955 from an earlier organization, the Soils Group, which had been formed in 1932 and was closely affiliated with the Canadian Society of Technical Agriculturists. Today the society has more than 500 members. The CSSS is affiliated with the Agricultural Institute of Canada, the Canadian Geoscience Council and the International Society of Soil Science. The CSSS holds annual meetings and technical sessions and in collaboration with the Agricultural Institute of Canada publishes the quarterly Canadian Journal of Soil Science. The CSSS honours distinguished soil scientists by bestowing fellowships in the society. More than 50 fellowships have been awarded since 1962, when the program was initiated.