2013 Fiscal Year Final Research Report
Mineralogical modification of volcanic ash soils
| Project/Area Number |
24658064
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Plant nutrition/Soil science
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| Research Institution | Kyushu University |
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Principal Investigator |
WADA Shin-Ichiro 九州大学, (連合)農学研究科(研究院), 教授 (60108678)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 火山灰土 / アロフェン / リン酸吸着 |
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| Research Abstract |
The objective of this study was to explore the possibility of 1) reducing phosphate absorption, 2) converting non-available iron and aluminum to calcium phosphates and 3) converting allophane into less phosphate-adsorbing minerals by applying converter slag.
An allophanic Andisol was packed in lysimeters with and without slag and aged. Soil pH and Ca and Mg concentrations increased as slag application rate increased. The water extracts from the soils that received > 4 t/10 a of the converter slag were oversaturated with respect to hydroxyapatite. The allophane and ferrihydrite contents did not change but the content of humus-bound aluminum drastically decreased by about 60%. The phosphate adsorption also decreased as the slag application rate increased. These results suggest that by converter slag application it is possible to reduce the phosphate absorption of Andisols and convert the aluminum and iron phosphate to calcium phosphates.
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