| Project/Area Number |
62480073
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 | UNIVERSITY OF TSUKUBA |
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Principal Investigator |
TADA Atsushi UNIVERSITY OF TSUKUBA, INSTITUTE OF AGRICULTURAL AND FOREST ENGINEERING, PROFESSOR, 農林工学系, 教授 (50133012)
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| Co-Investigator(Kenkyū-buntansha) |
TOYOMITSU Yukio UNIVERSITY OF TSUKUBA, INSTITUTE OF AGRICULTURAL AND FOREST ENGINEERING, RESEARC, 農林工学系, 助手 (70197979)
SAKUMA Taiichi UNIVERSITY OF TSUKUBA, INSTITUTE OF AGRICULTURAL AND FOREST ENGINEERING, ASSISTA, 農林工学系, 講師 (10133589)
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| Project Period (FY) |
1987 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1987: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Lotus Field / Farm Land Consolidation / Physical Properties of Soil in Lotus Field / Lot of Lotus Field / Farm Road For Lotus Fields / Soil Hardness of Lotus Fields / Depth of Plowed Layer for Lotus Field / 土壌物理性 / コーン指数 / 低平地 / 農道 / 用排水路 / 圃場区画 |
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| Research Abstract |
1. Physical Properties of Soil in Lotus Fields
The proper measurement methods of permeability and water pressure head while percolating, three phases ratio and soil hardness were examined in lotus fields.
The soil physical properties of plow and subsurface layer were measured in the shore of Kasumigaura Lake - Dejima-mura, Ibaraki. The results are as follows;
1) Plow layer has moisture ratio over 200 percent and the inadequate hardness for bearing capacity in the fields, because almost year-round lotus fields are flooded and the plow layers in lotus fields are deeper than in paddy fields.
2) If the soil hardness of plow layer is over a certain cone index, the problems in the quality and yield of lotus roots may be anticipated.
3) The optimum depth of plow layer is 30 to 35 cm for the fine quality and high yield of lotus roots.
4) Subsurface layer functioning as hard pan supports farmers and farm machines.
5) The soil physical properties in lotus fields were compared with those in adjacent pad
… More
dy fields.
2. Land Consolidation in Lotus Fields
Several case studies suggest the following informations.
1) Land consolidation in lotus fields can be planned similarly as in paddy fields.
2) The width of farm road is necessary to be 3.5 to 4.1 meters for two trucks to pass each other.
3) Considered from land grading, land decrease percentage, carrying out the harvested lotus roots and the other aspects, the intervals between access roads are recommended 200 meters.
4) The height of farm roads in lotus fields should be higher than in paddy fields because of soft and weak ground. For the same reasons, in some cases farm roads or levees should be made from hard and strong materials as concrete or sand bags.
5) The farm drain ditches in lotus fields can be constructed shallower than in paddy fields.
6) The larger the scale of a farm is or the less the number of lots cultivated by one farmer is, the bigger the size of farm lot can be planned. The enlargement of a lot may be accepted more than 30 a (30 m X100 m) in lotus fields. Less
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