| Project/Area Number |
02660238
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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 |
農業土木
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| Research Institution | Okayama University |
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Principal Investigator |
ADACHI Tadashi Okayama University, Faculty of Agric., Professor., 農学部, 教授 (20012007)
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| Co-Investigator(Kenkyū-buntansha) |
天谷 孝夫 岡山大学, 農学部, 助教授 (80033265)
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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 |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Acid sulfate soil / Muddy soil / Sulfur compound / Soil microorganism / Soil pH / Water content (pF) / 海成粘土 / 乾燥 / 土壌水分 |
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| Research Abstract |
The relation between the process of oxidation of sulfur compounds and the water content(water moisture suction)in a coastal muddy soil was examined.
The concentration of sulfuric ions increased with the progressing of oxidation of sulfur compounds containing in pyrite etc. and consequently the soil pH decreased in the coastal muddy soil. The treatment of salt removal enhanced the activity of microorganisms participating sulfur oxidation and formation of sulfuric ions. Actually, the soil pH decrease was occurred more greatly in the soil containing lower salt concentration.
In spite of the difference of the soil pF values, the soil pH decreased from 7.6 to 3.0 - 4.0, after two years drying of the soil. Especially, the oxidation of sulfur compounds occurred at the pF values of 4.0 to 4.4 and the lowest pH was observed at the pF 2.8.
Accordingly, we concluded that the decrease of soil pH in a coastal muddy soil was mainly occurred by microorganisms which oxidize sulfur compounds under the condition of higher-water than pF 3.0.
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