| Project/Area Number |
60480062
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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 |
林学
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
HAIBARA Kikuo Tokyo University of Agriculture and Technology. Associate Professor, 農学部, 助教授 (00014960)
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| Co-Investigator(Kenkyū-buntansha) |
KAWANA Akira Tokyo University of Agriculture and Technology. Honorary Professor, 名誉教授 (10014888)
AIBA Yoshinori Tokyo University of Agriculture and Technology. Professor, 農学部, 教授 (00014944)
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| Project Period (FY) |
1985 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1985: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Soil solution / Nutrient discharge / Fertilization / Pruning / 物質循環 / 地力 / 養分動態 / 人工造林地 |
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| Research Abstract |
The amounts of organic matter and nutrients supplied by weeding and pruning were large and seemed to play an important role in nutrient cerculation and site productivity before crown closure in the young stand. Evapotranspiration by weeds was estimated to be high in the young stand before crown closure and water loss(precipitation-discharge) after pruning decresed to about one-fourth that before pruning. The effects of fertilization on the quality of stream water occurred only during the period directly after clearcutting. There was a positive relationship between stream nutrient content and stream discharge except for the one to three years after pruning. It is important to prevent excess stream discharge and the subsequent loss of nutrients.
There were maintained mutural balance between the rate of exchangeable cations in soil and that of soil solution(suction at pF4.2). In case of increase of No3-N concentration in soil solution by fertilization included nitrogen, exhangeable K, Ca and Mg in soil were eluted into soil solution in order to keep the electrical equivalent.
Downward movement of fertilezed NO_3-N and K were easy in the lower part where was thick of A horizon and leaching-water amount of Ca and Mg were increased accompanied with increase of NO3-N in soil-water. Otherwize, downward movement of NO_3-N and K were not much in the upper part where was thin of a horizon. Especially, K was held almost in the surface horizon.
Movement of fertilized NO_3-N and K to the lower horizon was small quantity in the upper part with general precipitation and their elements were held in soil-water that was absorption some stronger force.
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