| Project/Area Number |
02660064
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
土壌・肥料
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| Research Institution | Mie University |
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Principal Investigator |
INUBUSHI Kazuyuki Mie University, Faculty of Bioresources, Associate Professor, 生物資源学部, 助教授 (00168428)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Paddt Soil / Soil Microorganisms / Microbial Biomass / Turn-over of Bioelements / Turn-over of Energy / Chloroform-fumigation / ATP / Nutrients-uptake by rice / 微作物バイオマス |
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| Research Abstract |
The roles of soil microorganisms are very important in the turn-over of bioelements and maintenance energy. But there are limited knowledge of microbial biomass and its activity in paddy soil. Aims of this research are to 1) establish the methods of biomass in paddy soil, 2) examine the quantitative relationship between biomass and nutrient uptake by rice plant, and 3) measure the adenylate energy charge (AEC) as an index of mirobial activity. Results are summarized as follows.
1. Determination of microbial biomass in paddy soil : Biomass C (carbon) in 11 kinds of paddy soils could be measured rapidly and precisely (correlation of variance < 5%) by chloroform fumigation-extraction method and total organic carbon analyzer. Calibration with the ordinal Tyurin method was carried out for soil extrct as well as standard solutions of glucose and potassium hydrogen phthalate. Correlation between biomass C and ATP (adenosin 5'triphosphate) was highly significant.
2. Microbial biomass N (nitrogen), inorganic soil N and N uptake by rice : Two kinds of paddy soils were used with or without rice plant for the pot experiment to elucidate N dynamics in paddy soil-plant ecosystem. Biomass N and inorganic N remained significantly lower in planted plots than in unplanted plots, implying active N turn-over from biomass to plant through inorganic soil N pool.
3. AEC in flooded and unflooded paddy soils : ATP and two other adenylic acids (ADP and AMP) were determined by luciferin-luciferase reaction and enzymes of myokinase, phosphoenol pyruvate and pyruvate kinase. AEC calculated from ATP, ADP and AMP decreased during flooding, while it kept high level in unflooded soil, indicating that microorganisms resistant to anaerobic condition could only survive in flooded soil.
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