| Project/Area Number |
17580050
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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 |
Plant nutrition/Soil science
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| Research Institution | Iwate University |
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Principal Investigator |
MIZOTA Chitoshi Iwate University, Faculty of Agriculture, Professor, 農学部, 教授 (10089930)
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| Co-Investigator(Kenkyū-buntansha) |
NOBORIO Kousuke Meiji University, Faculty of Agriculture, Professor, 農学部, 教授 (60311544)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | cattle slurry / volatilization of ammonia / nitrification / fractionation of nitrogen isotopes / 地下水汚染 / 黒ボク土 / 硝酸化成 / アンモニアの揮散 / 地下水の硝酸汚染 / 保水性 / 牧草地 |
|---|
| Research Abstract |
Organic nitrogen compounds in the animal waste once applied to soil are followed by chemical modification. Microbial transformation of nitrogen in cattle slurry applied to an Andisol grassland with no-cattle grazing over 20 years in northeastern Japan was analyzed with a focus on temporal changes in chemical composition (ammonium-and nitrate-nitrogen) and the natural abundance of nitrogen isotopes, δ^<15>N. Most urea and related metabolites, which were major organic constituents of nitrogen in cattle excreta, were hydrolyzed into ammonium-nitrogen during storage in an underground closed tank. Nitrification of the ammonium-nitrogen was largely delayed under lower soil temperature conditions with average air temperature (4-14℃), whereas rapid nitrification occurred under higher air temperature conditions (17-27℃). A coupled process of denitrification followed by nitrification was evidenced by a rapid decrease in the nitrate content with a simultaneous increase in the δ^<15>N values of the residual. Such a process was facilitated by a combination of the high water retention property of the Andisol with an ample supply of organic matter.
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