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oai:www.ideals.illinois.edu:2142/87667 2023-07-11 col_2142_5131 col_2142_34137 com_2142_5130 com_2142_34136 com_2142_397

2015-09-28T16:22:33Z 2015-09-28T16:22:33Z 10000-01-01 1997 1997 Stucki, Joseph W. Huo, Dongfang Ca and K selectivity in the interlamaller space of the unaltered, reduced, and reoxidized ferruginous smectite (SWa-1) was studied. The results of this study can be applied to estimate fertilizer K availability in the production field. Cation exchange method was used in this study. In the unaltered clay mineral, Ca displayed a strong preference over K. This preference, however, was reversed when the clay was chemically reduced with sodium dithionite. When the reduced clay was reoxidized, Ca, again, displayed a preference over K, but the ratio of Ca to K was not restored to the original extent. The selectivity of cations in the interlamaller space of SWa-1 also depended on the ratio of Ca to K in the exchanger solution, and on the total concentration of the exchanger solution. Those results indicate that the conventional estimation of the available K based solely on the mineral composition of the soil-clay fraction is insufficient. The redox state of soil-clay and the competing cations (Ca and Mg most common) also play very important roles in controlling K availability. Made available in DSpace on 2015-09-28T16:22:33Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9812635.pdf: 5561074 bytes, checksum: 0bbba49b31034c245c23e61e534d61a5 (MD5) Previous issue date: 1997 Embargo set by: Seth Robbins for item 88948 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community indefinitely during batch ingest of legacy ETDs U of I Only 139 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997. http://hdl.handle.net/2142/87667 (MiAaPQ)AAI9812635 eng Geochemistry Infrared Study of Oxidized and Reduced Nontronite and Ca-K Competition in the Interlayer text Agronomy Agronomy University of Illinois at Urbana-Champaign Dissertation Ph.D.