2015 Fiscal Year Final Research Report
Activity of nitrogen cycling and soil microbial community in paddies without fertilizer application
| Project/Area Number |
26550092
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Design and evaluation of sustainable and environmental conscious system
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| Research Institution | Hirosaki University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Keywords | 水田 / 無施肥 / 収量 / 窒素循環 / 土壌微生物 / 有機物分解 |
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| Outline of Final Research Achievements |
Although it is expected that high crop yield is possible only under appropriate fertilizer application, a few farmers in Tohoku region have been attained high rice yield without any application of chemical fertilizer during 40 years. To clarify the mechanisms behind high yield without fertilizer application comparison was made between high-yield paddies and low-yield paddies without long term fertilizer application in a Tohoku region.
The high-yield paddies had a higher capacity to supply mineralized nitrogen from soil and attained high yield (480kg 10a) comparable to conventional farming. This high yield resulted from (1) a larger amount of rice straw of previous crop available for decomposition and (2) higher decomposition activity of soil microbes. However, nitrogen fixation by soil bacteria seem to contribute for the high yield to compensate nitrogen loss by taking out of nitrogen contained in rice grain from a filed.
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| Free Research Field |
生態学
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