- Volume 10, Number 3 (2023)
COMPARING SOIL PROPERTIES IN ALLOPHANIC AND NONALLOPHANIC LAYERS OF VOLCANIC ASH SOIL: INSIGHTS FROM KYUSHU, JAPAN
Hiroshi Tanaka, Takeshi Yamamoto
Andosols, characterized as soils formed from volcanic ash, constitute the cornerstone for upland agriculture in Japan. These soils are further categorized into allophanic and non-allophanic types. Allophanic Andosols, covering 4.51 million ha or 69.9% of the total Andosol area, are primarily located in regions with substantial Holocene tephra deposits. Conversely, non-allophanic Andosols, accounting for 1.95 million ha or 30.1% of the total Andosol area, predominate in areas with minor tephra deposition (Saigusa and Matsuyama, 1998). While both types share core properties such as a thick black A-horizon, high phosphate fixation, excellent water retention, and low bulk density, non-allophanic Andosols exhibit...