Overview

Abstract

This chapter provides the overview of soil types, land uses, and land managements of Japan. The soils of Japan are immature soils developed from the flesh parent materials such as volcanic tephra or ejecta or eroded or deposited materials in various landscapes from mountain terrain to alluvial plains within about 10,000 years. Japanese soils are generally acidic, since the basic cations of soils are leached by the high precipitation of the monsoon climate. According to the soil classification system of Japan newly developed in 2017, Brown Forest soils, Andosols, Fluvic soils, Red-Yellow soils, and Regosols cover 33.2, 30.3, 13.7, 7.6, and 6.9% of the country, respectively. In land uses of Japan in 2016, forests occupy 63.5% of the total land area of Japan (37.8 million ha). Cultivated land area was 4.47 million ha, which accounts for 12.0%. However, the cultivated land area has continuously decreased from 6.08 million ha in 1961. In Japan, from 1959 to 1978, the Fundamental Soil Survey for Soil Fertility Conservation was carried out and classified the crop production potential of cultivated land soils into four grades. Based on the results of the soil survey, field improvements have been performed to ameliorate the limiting factors for crop production. This has made it possible to set the fertilization standards for each crop in each region. The fertilization standards are defined as the amount of fertilizer that achieves the target yield without causing environmental issues and are the bases of the environmentally friendly agriculture. Based on the efforts in each region, in 1999, Japanese government enacted the Act on Promotion of Introduction of Sustainable Agricultural Production Practices.