2003 Fiscal Year Final Research Report Summary
Assessment of water and solute transport characteristics during salt accumulation and leaching, and establishment of proper soil management for sustainable agricultural production in arid and semi-arid regions.
| Project/Area Number |
13460104
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Irrigation, drainage and rural engineering/Rural planning
|
|---|
| Research Institution | Tottori University |
|---|
Principal Investigator |
INOUE Mitsuhiro Tottori University, Arid Land Research Center, Associate Professor, 乾燥地研究センター, 助教授 (90032309)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
AKAE Takeo Okayama University, Faculty of Environmental Science and Technology, Professor, 環境理工学部, 教授 (10123423)
HONNNA Toshimasa Tottori University, Faculty of Agriculture, Professor, 農学部, 教授 (90093624)
YAMAMOTO Tahei Tottori University, Arid Land Research Center, Professor, 乾燥地研究センター, 教授 (00032102)
TAKUMA Katsutoshi Tottori University, Faculty of Agriculture, Professor, 農学部, 教授 (40032297)
KIHARA Yasutaka Shimane University, Faculty of Life and Environmental Science, Lecturer, 生物資源科学部, 講師 (30204960)
|
|---|
| Project Period (FY) |
2001 – 2003
|
| Keywords | salt accumulation / leaching / evaporation process / gravel mulch / saline soil / sodic soil / numerical simulation / sand dressed |
|---|
| Research Abstract |
Objective of this study was to clarify solute movement following salt accumulation and leaching in arid areas and to establish proper soil management to prevent soil degradation from over-irrigation. In this study, measurement of water flow and solute transport during evaporation was carried out during salt accumulation process under constant high ground water level using large column. After measuring the relationships among salt content, water content and soil albedo, it was found that the albedo of soil surface increased with increasing mass of accumulated salt. The horizontal distribution of rystallizied soils was investigated using digital analysis of salt crust caused by salt accumulation. Effects of gravel mulch on evaporation with emphasis on resistance to water vapor transfer above and below the soil surface were discussed. Effects of leaching water quality on hydraulic properties of saline soils were also discussed and the aggregate stability of sodic soils was evaluated. Move
… More
ment of cations under accumulation and leaching processes in soils was discussed. WASH-1D software for one-dimensional numerical simulation of water flow, solute and heat movement in soils was developed in order to simulate salt accumulation with evaporation and leaching due to rainfall. A flux-controlled steady-state evaporation method was proposed for determining unsaturated hydraulic conductivity at low matric pressure head values. A simple method of measuring soil thermal conductivity as well as the influences of water content, solute concentration, and temperature on thermal conductivity of dune sand were discussed. Differences in electrical conductivity of the soil water between continual and intermittent irrigation were observed during grain sorghum cultivation. Dynamics of soil water and salt in sand-dressed upland field with salinized ground water due to sea water intrusion was measured and simulated. It was established that sand dressing was useful to prevent soil salinization. Less
|
