|
|
||||||||
ABSTRACT
A mica-vermiculite material was treated with MgCl2 and converted to a typical Mg-vermiculite. The same material was treated with AlCl3 and converted to a 14Å. mineral concluded to be a vermiculite-chlorite intergrade similar to those recently reported in the literature. AlCl3 treatment of Mg-vermiculite also resulted in intergrade formation. In B22 and C horizon samples of a Dayton soil, added aluminum blocked K fixation and increased K release when samples were cycled through various wetting and drying treatments. The roles of aluminum in release of K and in intergrade mineral formation were shown to be interrelated. It was concluded that Al3+ replaces K+ in mica and Mg2+ in vermiculite lattices and then probably forms a sixfold coordination compound with H2O or (OH)- which blocks lattice collapse upon subsequent K-saturation. The increase in exchangeable K upon drying of soils appears to be related to the replacement of fixed K+ by Al3+ arising from degradation of minerals.
1 Joint contribution from the Soil and Water Conservation Research Division, ARS, USDA, and the Department of Soils, Oregon State University, Corvallis. Technical paper No. 1536, Oregon Ag. Exp. Sta.
2 Research Soil Scientist, SWCRD, ARS, USDA, Associate Soil Scientist, Oregon Agr. Exp. Sta., and Chemist, SWCRD, ARS, USDA, respectively. Senior author's present address: P. O. Box 267, Weslaco, Tex.
Received for publication June 18, 1962. Accepted for publication October 26, 1962.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||