Anthropogenic Pedofeature in Andosols in Santome Shinden, One of the Representative Sites of the Satoyama Environment in Japan

Santome Shinden, a representative site of the Satoyama landscape in Japan, has its origins in 1696 when the common land of wild grass on the Musashino plateau was developed into a strip-shaped land division, which consists of residential area, upland field, and secondary forest. We investigated soils with different land use over 300 years; they are under the secondary forest, and in the upland field where fallen leaves compost derived from secondary forest has been applied continuously for about 300 years since the development. The measured exchangeable cation values suggested that the nutrients in the secondary forest were taken out to the field as fallen leaves. On the surface layer of the upland field soil, characteristic granules of dark brown coated peds (DBC peds) were developed strongly. However, on the surface layer of the secondary forest soil, the DBC peds were not found. Electron probe micro analyzer analysis showed that the outside (dark brown part) of the DBC peds, which was observed only in the upland fields was rich in carbon. The dark brown coated pedofeature was suggested to have an anthropogenic effect due to the long-term application of fallen leaves compost. The anthropogenic activities, which were fallen leaves compost application and cultivation for about 300 years, were thought to affect the soil micromorphology. Therefore, the peds newly found in the Santome shinden field were considered to be a soil microstructure that symbolizes anthropogenic activities.