| Project/Area Number |
16K00638
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Environmental and ecological symbiosis
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| Research Institution | Otsuma Women's University |
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Principal Investigator |
Koseki Yusuke 大妻女子大学, 家政学部, 准教授 (00513772)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2018: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | 環境配慮型農法 / 環境保全型農法 / 稲田養魚 / 水田養魚 / 生態系機能 / 生態系サービス / 安定同位体比 / 物質フロー / 自然共生システム |
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| Outline of Final Research Achievements |
To elucidate mechanisms underlying high productivity of rice-fish culture, organic matter flows in rice fields were estimated using carbon and nitrogen stable isotope ratios. Rice-fish fields were characterized by higher supply of animal-derived organic matter than conventional rice fields. The animal-derived organic matter in rice-fish fields was accounted for to a significant degree by fish (crucian carp) feces, but a larger proportion was accounted for by leftover feed. A certain proportion of crucian carp diet was accounted for by natural food, although fish feed contributed to a greater proportion. These results show that autochthonous food chain of the rice-fish ecosystem plays a certain role in soil enrichment but that allochthonous input of fish feed has a greater impact on soil nutritional status, resulting in high productivity of the culture system.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究は、伝統的農法「稲田養魚」において、かつて「米魚両全」と評された高い単収の背後にある生態系プロセスを炭素窒素安定同位体を用いて調査し、魚が排泄するふんが有機肥料となり水稲の玄米生産に利用される「施肥効果」の過程を初めて科学的に明らかにした。米魚両全を支える生態系プロセスが明らかになったことで、今後稲田養魚を新たに自然共生型農法として位置付け、その普及推進を図っていくための科学的根拠が整備された。
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