| Project/Area Number |
58860035
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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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 | Iwate University |
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Principal Investigator |
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| Project Period (FY) |
1983 – 1985
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| Project Status |
Completed (Fiscal Year 1985)
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| Budget Amount *help |
¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 1985: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1984: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1983: ¥3,200,000 (Direct Cost: ¥3,200,000)
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| Keywords | field reclamation at improved slope / top soil loss by erosion / catch levee / top soil dressing / soil erosion / seedbed making / soil hardness / 水質汚濁 |
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| Research Abstract |
The experimental ordinary field and grassland having 5 ha. respectively are reclamed at improved slope in the NANGO village, AOMORI Prefecture. The reclamation planning and design of this experimental site and its institutions for preventing soil erosion are carried out in this project. The effects of these reclamation planning and design are investigated as follows:
1. Ordinary field
(1) It is obvious that the field topography correlate to soil erosion. Land form having a convex surfce disperse the rain fall run off and reduce the soil erosion. On the other hand the concave land form concentrate the run off on the bottom site and intensify the soil erosion in that. Therefore the design of field construction should be performed the convex land form.
(2) Field institutions such as catch levee, silting weir and grassed waterway-road having a shallow V type section are effective for prevention of top soil erosion. They have a large section for run off water and can cathches much silting soils and doesn't bury in them. Also these are planned and constructed with a less-costed method.
(3) Rain fall retaintion in the field increases with the years after reclamation. This increase is due to the enlargement of infiltration in field soil layer and this infiltration increases with the root pores formed by the crop plants and cracks developed by soil drying. Further, the top soil dressing contribute to the increase of rain fall retaintion.
2. Glassland
(1) Graded land form and institutions are similar to ordinary field and good results are obtained. It can finds neither collapse, erosion nor water pollution during reclamation.
(2) The top soil dressing and cultivation are abbreviated for making seedbeds and seeds are pressed with a bulldozer instead of a tractor. But a good yield and quality of grasses can be gotten by soil improvement and fertilizer application.
(3) The top soil hardness is investigated according to real state of expreimental divisions in grassland.
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