ABSTRACT
Japan is a country with a high density of population and intensive agricultural production. It is not surprising that from the end of the 19th century a survey of soil resources was undertaken. Initially, the survey was completely agrogeological, then in the 1920s the concept of soil series was introduced, and, finally, a soil taxonomic classification developed starting in the 1950s (Hirai and Hamazaki, 2004). The latest version of the Japanese soil classification was published in 2002 continuing a lengthy effort of a group of pedologists (Fourth Committee for Soil Classification and Nomenclature, 2002). The classification is limited to the national borders of Japan (Table 24.1). The system includes man-made soils; however, rock outcrops and underwater sediments are not recognized as soils. Artificially flooded paddy soils are classified as soils as they represent important agricultural resources of the country. Soils transformed by agricultural practices, depending on the degree of transformation, are included in the classification at different levels. Soils completely reworked by tillage appear in the great group of Man-made soils, paddy soils form two groups in the great group of Fluvic soils, and less transformed soils are included as Anthraquic subgroups to a number of soil groups. The scope of soil classification of Japan
|
Superficial bodies |
Representation in the system |
|---|---|
|
Natural soils |
National coverage |
|
Urban soils |
Partly included in the great group of man-made soils |
|
Man-transported materials |
Partly included in the great group of man-made soils |
|
Bare rock |
Not recognized as soils |
|
Subaquatic soils |
Not recognized as soils |
|
Soils deeply transformed by agricultural activities |
Included in great group, group and subgroup levels |
