1990 Fiscal Year Final Research Report Summary
Studies on International Classification of Tephra-Derived Spodosols
| Project/Area Number |
01470153
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
土壌・肥料
|
|---|
| Research Institution | Tohoku University |
|---|
Principal Investigator |
SHOJI Sadao Tohoku University, Dept. of Agriculture, Professor, 農学部, 教授 (10005605)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Tadashi Akita Prefectural College of Agriculture, Dept. of Agriculture Lecturer, 講師 (80132009)
木村 和彦 東北大学, 農学部, 助手 (10183302)
ITOU Toyoaki Tohoku University, Dept. of Agriculture Assistant, 農学部, 助手 (10176349)
|
|---|
| Project Period (FY) |
1989 – 1990
|
| Keywords | Andisol / Spodosol / Andic Soil Properties / Spodic Criteria / Soil Taxonomy / Volcanic ash soil |
|---|
| Research Abstract |
Tephra-detived Spodosols and Andisols share many important chemical properties which make it difficult to definitely separate the two orders (Ping et al. 1989 ; Shoji et al. 1988a, 1988b). In order to solve this serious problem, it has been proposed to exclude soils having andic properties from Spodosols (Arnold et al. 1989 ; Blume et al. 1989 ; National soil Survey Quality Assurance Staff (NSSQAS) 1989). However, we consider that all soils showing characteristic morphology of Spodosols should be classified as Spodosols irrespective of the kind of parent materials. According to our studies on volcanic ash soils in northeastern Japan and Alaska and Washigton, U. S. A., we proposed classification of tephra-derived Spodosols including the important items as follows : 1) To recognize tephra-derived Spodosols showing characteristic morphology of Spodosols, 2) To key out Spodosols after Andisols, 3) Emphasis on morphology over chemical spodic criteria, 4) Modification on albic color requirement for tephra-derived Spodosols, 5) Proposal of a new chemical spodic criterion (oxalate Al and a half Fe), and 6) Proposal of a procedure to differentiate a spodic horizon from a buried A horizon.
|
