1991 Fiscal Year Final Research Report Summary
Effect of soil structure on water and solutes movement
Project/Area Number |
01420043
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Research Category |
Grant-in-Aid for General Scientific Research (A)
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Allocation Type | Single-year Grants |
Research Field |
農業土木
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Research Institution | Kyoto University |
Principal Investigator |
MARUYAMA Toshisuke Kyoto Univ., Fac. of Agriculture, Professor, 農学部, 教授 (90026451)
|
Co-Investigator(Kenkyū-buntansha) |
HORINO Haruhiko Kyoto Univ., Fac. of Agriculture, Instructor, 農学部, 助手 (30212202)
WATANABE Thugihiro Kyoto Univ., Fac. of Agriculture, Associate Professor, 農学部, 助教授 (50175105)
KOBAYASHI Shintaro Kyoto Univ., Fac. of Agriculture, Associate Professor, 農学部, 助教授 (20026602)
KYUMA Kazutake Kyoto Univ., Fac. of Agriculture, Professor, 農学部, 教授 (80027581)
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Project Period (FY) |
1989 – 1991
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Keywords | Soil structure / Macropore / Soft X-ray / Permeability / Water retentivity / Stereo photograph / Image analysis |
Research Abstract |
Effect of soil structure on water and solutes movement was examined visually as the basis of soil water movement. Consequently following results were obtained. The method developed here made it easier to evaluate macropore structure quantitatively. (1) Stereo radiograph was obtained efficiently by infiltlating a contrast medium into undisturbed soil sample using soft X-ray, so pore structure was observed with 3-D images. (2) It was shown that specific soil structure was made with time according to land-use, such as paddy field and upland field. (3) Rotted rice roots are found inside the macropores in paddy field not only on the microscopic photos but also on the radiographic photos. These facts reveals macropores are made by rice roots in paddy field, and that it contributed significantly in transferring the matter in soils. (4) Fluid movement inside the soil which has not been reported until now was observed. It shows the fact that fluid moves inside rather small number of macropores in which fluids moves faster than others. Furthermore, it also became possible to calculate the permeability directly on photos by measuring the diameters of macropores. Some features were discussed on permeability comparing these datum with the results of usual permeability tests. At this point, further discussion is expected on relationships between two datum. (5) Because water retentivity depends on micropores, difficulty in explaining the relationships between moisture characteristic curve and soil structure is recognized.
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Research Products
(6 results)