抄録
The early zonal concept recognized three soil geographic zones in Japan represented by podzolic, brown earth and red soils from north to south. Recently accumulated numerous pedological data have shown the need to revise this concept, and 27 genetic soil types of which 4 are zonal, 18 are intrazonal and 5 are azonal, are proposed. The role of each soil former is then discussed in terms of newly established soil types and subtypes. In conclusion, revised soil zones are proposed as follows: Hokkaido and northernmost Honshu belong to the zone of the brown forest soils with the recognition of two subzones, and yellow-brown forest soils are proposed as the zonal soils of the former "red soil" zone, since the red soils are now known to be paleosols. Many of intrazonal soils are closely associated with a particular soil zone, but the volcanic Kuroboku soils occur in all zones probably because of the strong influence of parent material and secondary grassland vegetation.
