Introduction to Mineralogy of Soil Environments.
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Accession number;99A0371851
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| Title;Introduction to Mineralogy of Soil Environments. |
| Author;
KODAMA HIDEOMI
(Univ. Ottawa, Ontario, Can)
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Journal Title;Journal of the Mineralogical Society of Japan
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Journal Code:G0124A
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ISSN:0454-1146
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VOL.28;NO.1;PAGE.13-21(1999)
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| Figure&Table&Reference;FIG.2, TBL.4, REF.25 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;This article describes a series of research done on the mineralogy of Canadian soils by the author and his colleagues over the past 35 years. During the period, 1962-77, the research was devoted to the characterization of minerals in soils and sediments with continuing effort to improve analytical methods for mineral identification and characterization. Of the research, a major difference in the clay mineral composition of the western praine soil and eastern maritime soils was highlighted here. The prairie soils are smectitic, whereas the maritime soils are micaceous. It was noted, however, that potassium available to plants is always sufficient in the prairie soils but not in the maritime soils, although both soils have similar K2O content ( - 3% ). This is obviously reflected in the smectitic composition of the prairie soils. The composition includes smectite and vermiculite component layers as interstratified minerals, all of which can release K relatively easily than illites in the maritime soils as discrete or/and interstratified minerals. In the following 10 years from 1978-87, the research focused on various interactions of clay minerals with soil organic matter and inorganic compounds, as well as on the detection of poorly crystalline inorganic components in soils. Expandable clay minerals such as smectite can adsorb water-soluble soil organic matter between the layers only under low pH conditions, because under these conditions the majonty of soil organic matter molecules are relatively undissociated and mostly remain neutral. At higher pH, the molecules dissociate negatively. This illustrates the importance of pH-dependent charge in the soil system. Oxide, oxyhydroxide, and hydroxide minerals occurring in soils also possess pH-dependent charge, thus they react as positively or negatively charged particles depending upon pH, unlike clay minerals which are permanently negatively charged.... (author abst.) |
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