| Project/Area Number |
14560049
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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 | YAMAGATA UNIVERSITY |
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Principal Investigator |
KASUBUCHI Tatsuaki YAMAGATA UNIVERSITY, FACULTY OF AGRICULTURE, PROFESSOR, 農学部, 教授 (00250960)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2003: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2002: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | ponded paddy field / wetland / automated measuring system / physical and physicochemical environment / CO_2 / absorption / deep ponding irrigation / CO_2ガス / 温室効果ガス / pH / RpH |
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| Research Abstract |
It is indispensable to measure the physical and physicochemical environments of a paddy field and wetland for the sustainable agricultural production and environmental preservation.
In 2002 we had made a CO_2 measuring system for atmospheric distribution near the ponded layer and found that the water layer absorbed CO_2 from the air in daytime by the high pH, which was caused by photosynthesis of algae near the soil surface. This means that the ponded paddy field contributes to protect greenhouse effect beyond expectation. And for the sustainable agricultural production it is effective to utilize the photosynthetic bacteria like algae.
In 2003 we measured the heat balance and related factors of paddy field to analyze the the deep ponding irrigation. The deep ponded water layer by the irrigation was expected to affect the thermal regime of water and soil layer since the water layer brought about unique thermal regime. To clarify the effect, we measured factors of heat balance in water and soil layer together with meteorological factors using lysimeters of various ponding water under high and low solar energy condition. Under high solar energy condition, the amount of diurnal net heat energy change, which is the difference between the accumulated and the released heat of the total of water and soil layer, was positive and the accumulation also increased with the water depth. However, under low solar energy condition, it was negative and the emission also increased with the water depth. One of the major reasons for these differences is the change of evaporation with the water depth. The deep ponding irrigation doesn't always have heat-insulating effect but has effectiveness to avoid cold weather damage.
These results show that the automated measuring system for physical and physicochemical environment is effective to clarify the mechanism of ecological and sustainable management for agricultural field and natural wetland.
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