2005 Fiscal Year Final Research Report Summary
The study on the sustainability of nitrogen removal on paddy soil
| Project/Area Number |
14360138
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Ibaraki University |
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Principal Investigator |
KURODA Hisao IBARAKI University, College of Agriculture, Associate professor, 農学部, 助教授 (20205256)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Tasuku IBARAKI University, College of Agriculture, Lecture, 農学部, 講師 (10302332)
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| Project Period (FY) |
2002 – 2005
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| Keywords | Nitrogen removal / Light condition / Organic matter / TOC / C / N / Daily change / Soil |
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| Research Abstract |
It is experimented for the sustainability of nitrogen removal. The soil used in the experiment is sampling from a flood controlled test field that has been non-vegetation since 1991. 1cm of soil surface layer is taken, and the soil was rested for 24 hours and surface water was removed. The 100g soil was put into a beaker, and 300cm^3 NO_3-N of different concentration(10, 20, 40mg・L^<-1>) was added to it. An illuminated incubator was used to change the temperature and light condition to adapt to nature's condition. And, a fixed light and temperature experiment is carried out. To compare the result of the experiment, dark condition samples covered aluminum foil. In light condition, algae growth is noted. Organic matter has great influence in nitrogen removal is understood. Nitrogen removal ability with the existence of light and dark condition and the difference in soil layer thickness, nitrogen removal can be expected in above 10mm soil layer. Any land with above 10mm soil layer can be targeted as nitrogen removal area. In the experiment where light is continuously irradiated, algae grow and nitrogen removal ability is 2 times more than in dark condition. The light condition of daily change experiment is that night(from 19:00 to 5:00) is 0μmol・s^<-1>・m^<-2>, early morning(from 5:00 to 7:00) and evening(from 17:00 to 19:00) is 60μmol・s^<-1>・m^<-2>, the daytime(from 7:00 to 17:00) is 250μmol・s^<-1>・m^<-2>. Temperature was set from test field value. To examine the effect of light condition, we carried out experiment that is fixed light intensity/temperature, light intensity variation (temperature fixed), temperature variation (light intensity fixed) conditions. The result showed the amount of nitrogen removal became a large value with light intensity variation. And it is even bigger than continuous irradiation. This is because when light is on at all time, oxidation condition progressed on. And the denitrification became difficult.
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Research Products
(11 results)
