| Project/Area Number |
60560337
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
農業土木
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| Research Institution | Ishikawa Agricultural College |
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Principal Investigator |
KANO Toshihiro Ishikawa Agricultural College, その他, 教授 (60070835)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1986: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Basic in take rate / Infiltration capacity / Infiltration with wetting front / Percolation / Soil water / Field capacity / Transition of infiltration |
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| Research Abstract |
The transition of vertical infiltration defined as the rapid development of infiltration from first infiltration being the dominant region of matric suction to second infiltration being the dominant region of gravity has been observed in almost cases in the field observation for measuring intake rate within the time period of usual field irrigation.
It has become clear that values of basic intake rate calculated from a equation for the first infiltration region are very smaller than them for the second infiltration region. Therefore, the former are not adequate for use as essential data of design and planning of field irrigation project.
Accordingly, it has been necessary that the time required for the second-infiltrarion to be duly confirmed should be settled by a detailed study with extensive investigation in the fields in order to be determined proper intake rate in the field irrigation.
As a result of intensive investigation of intake rate based on the data measured in both rotational farm field and newly reclaimed farm fields, the following facts became clear in terms of the time span required for measurement of intake rate:
1. About 1-2 hr. in dry(C.M.E.) condition and about 2-3 hr. in wet (F.C.) condition are required for sandy loam soil. 2. About 2-3 hr. in dry condition and 5-6 hr. in wet condition are required for loamy soil. 3. About 3-4 hr. in dry condition and 6-7 hr. in wet condition are required for clayey loam soil. These findings indicate that the conventional time span of about 100 minutes is rather shorter than actual time span needed for estimating a proper basic intake rate and improvements must be made in time on the present procedure for measuring of in take rate.
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