Abstract
Despite the development of soil classification system for all land use, there have been no progresses of the soil map delineation in Japan. Several studies pointed out that the distribution area of Andosols could be wider than that on the old soil map (National Land Survey project, NLS) in Hokuriku and Chubu districts. In this study, we delineated new soil maps of these districts (1:200,000) according to the Comprehensive Soil Classification System of Japan First Approximation (CSCJ) and Unified Soil Classification System of Japan (2nd Approximation) (USCJ). From the new CSCJ soil map, Brown Forest soils (distribution area; 31%) was the most dominant soil great group in these regions, and followed by Andosols (27%) and Lowland soils (17%). Comparing CSCJ soil map with NLS, the distribution area of Andosols increased from 5% (NLS) to 27% (CSCJ), and that of Brown Forest soils decreased from 63% (NLS) to 31% (CSCJ). On the other hand, the distribution area of each soil great group in CSCJ soil map wasn’t different from that in USCJ soil map. However, a part of distribution area classified to Red-Yellow soils and Brown Forest soils by CSCJ soil map was changed to another soil great group by USCJ soil map. Furthermore, in spite of cool soil temperature of this region, the distribution of Yellow-Brown Forest soils was dominant in Brown Forest soils great group area in USCJ soil map.
