crystal soil

The first formal system of soil classification was introduced in the United States by Curtis F. Marbut in the 1930s. This system, however, had some serious limitations, and by the early 1950s the United States Soil Conservation Service (now the Natural Resources Conservation Service) began the development of a new method of soil classification. The process of development of the new system took nearly a decade to complete. By 1960, the review process was completed and the Seventh Approximation Soil Classification System was introduced. Since 1960, this soil classification system has undergone numerous minor modifications and is now under the control of Natural Resources Conservation Service (NRCS), which is a branch of the Department of Agriculture. The current version of the system has six levels of classification in its hierarchical structure. The major divisions in this classification system, from general to specific, are: orders, suborders, great groups, subgroups, families, and series. At its lowest level of organization, the U.S. system of soil classification recognizes approximately 15,000 different soil series. Figure 14: Luvisol Profile. (Source: Soil Landscapes of Canada, Version 2.2, Agriculture and Agri-Food Canada. 1996) The first formal system of soil classification was introduced in the United States by Curtis F. Marbut in the 1930s. This system, however, had some serious limitations, and by the early 1950s the United States Soil Conservation Service (now the Natural Resources Conservation Service) began the development of a new method of soil classification. The process of development of the new system took nearly a decade to complete. By 1960, the review process was completed and the Seventh Approximation Soil Classification System was introduced. Since 1960, this soil classification system has undergone numerous minor modifications and is now under the control of Natural Resources Conservation Service (NRCS), which is a branch of the Department of Agriculture. The current version of the system has six levels of classification in its hierarchical structure. The major divisions in this classification system, from general to specific, are: orders, suborders, great groups, subgroups, families, and series. At its lowest level of organization, the U.S. system of soil classification recognizes approximately 15,000 different soil series. Andisols develop from volcanic parent materials. Volcanic deposits have a unique process of weathering that causes the accumulation of allophane and oxides of iron and aluminum in developing soils.

Figure 20: Regosol Profile. (Source: Soil Landscapes of Canada, Version 2.2, Agriculture and Agri-Food Canada. 1996) * Brunisol - is a normally immature soil commonly found under forested ecosystems. The most identifying trait of these soils is the presence of a B horizon that is brownish in color. The soils under the dry pine forests of south-central British Columbia are typically brunisols. Figure 21: Saline Solonetzic Landscape (Saskatchewan). (Source: Soil Landscapes of Canada, Version 2.2, Agriculture and Agri-Food Canada. 1996) Figure 6: Brunisol Profile. (Source: Soil Landscapes of Canada, Version 2.2, Agriculture and Agri-Food Canada. 1996) Aridsols are soils that develop in very dry environments. The main characteristic of this soil is poor and shallow soil horizon development. Aridsols also tend to be light-colored because of limited humus additions from vegetation. The hot climate under which these soils develop tends to restrict vegetation growth. Because of limited rain and high temperatures soil water tends to migrate in these soils in an upward direction. This condition causes the deposition of salts carried by the water at or near the ground surface because of evaporation. This soil process is called salinization. Figure 13: Luvisolic Sub-Boreal Forest Landscape (Northern British Columbia). (Source: Soil Landscapes of Canada, Version 2.2, Agriculture and Agri-Food Canada. 1996)