| Project/Area Number |
10660257
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Zootechnical science/Grassland science
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| Research Institution | Tokyo University of Agriculture and Technology |
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Principal Investigator |
KUROKAWA Yuzo Tokyo University of Agriculture and Technology, Faculty of Agriculture, Assistant Professor, 農学部, 助手 (00234592)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Haruo Tokyo University of Agriculture and Technology, Faculty of Agriculture, Assistant Professor, 農学部, 助手 (20236615)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1999: ¥400,000 (Direct Cost: ¥400,000)
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| Keywords | combined system / grazing / cutting / forage production / cattle gain / soil nitrogen / pasture management / nitrogen budget / 土壌中無機機態窒素 / 窒素施肥 / 牧草収量 / 溶脱 / 土壌中硝酸態窒素 / 牧草中硝酸態窒素 / 硝酸態窒素溶脱量 |
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| Research Abstract |
Nitrogen budgets on a pasture being utilized for both grazing and cutting were investigated in 1999 and 2000. A pasture (0.9 ha) containing tallfescue, orchardgrass and white clover was divided into two (1999) or three (2000) areas : an initially grazed area and areas grazed after cutting for hay or silage. A herd of 4-5 cattle (heifers or steers of Japanese Black or Holstein) grazed at one, two and all of the areas. The amount of herbage N production from the areas where cattle grazed for longer period was higher than the sum of N of grazed herbage and harvested hay from the areas where cattle grazed for shorter period. The amount of N inflow to soil as fertilizer (applied in 1999 only) or animal excreta seemed to relate to the difference in herbage production between the areas. The value of N surplus for the whole pasture was very similar among the areas in each year. But the N surplus in 1999 was higher than that in 2000. It is suggested that the difference was caused by the facts that fertilizer was applied only in 1999 and that silage production in 2000 was higher than that of hay production in 1999. Soil nitrogen contents of some forms were investigated only in 2000. There was little difference in available nitrogen contents in soil among areas. The mineralized soil nitrogen contents in the longer-grazed areas were higher than those in the shorter grazed area. So, longer-grazing may have lead to some increase in nitrogen leaching from soil.
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