| Popis: |
The Japanese Society of Pedology released the “Soil Classification System of Japan,” the latest version of the comprehensive soil classification system in Japan. According to this classification system, the area of each soil group is calculated and soil map is produced. Andosols are found along volcanic areas, Brown Forest soils and Cambic Red-Yellow soils (refer to Cambisols) are distributed in steep mountainous zones far from active volcanoes, and Fluvic soils cover narrow lowlands. Cultivated land accounts for 12% of the total land surface and is mainly distributed in the plains. Thus, Fluvic soils show the largest distribution area (47%), followed by Andosols (29%) in the cultivated land. Nutrient imbalance, soil organic matter decline, heavy metal contamination, and soil sealing are major threats to Japanese agricultural soils. |
