Mineralogy of Rhizospheric and Non-Rhizospheric Soils in Corn Fields*

Hideomi Kodama1, Sherman Nelson1, Ann Fook Yang2 and Norihiko Kohyama3
1 Centre for Land and Biological Resources Research, Agriculture Canada Ottawa, Ontario, Canada K1A OC6
2 Plant Research Centre, Agriculture Canada, Ottawa, Ontario, Canada K1A OC6
3 National Institute of Industrial Health, Ministry of Labour 21-1, Nagao 6-chome, Tama-Ku, Kawasaki, Japan
* CLBRR Contribution No. 94-04. PRC Contribution No. 1534.

Abstract: Technical limitations have restricted investigations of rhizosphere mineralogy. Various analytical techniques were applied to assess root-mineral associations and dynamics in natural soils under corn production. Soil samples were collected between four and five weeks after planting and included rhizospheric and non-rhizospheric soils, and undisturbed block samples containing corn root systems. Analytical techniques were applied and included; X-ray diffraction, optical microscope, SEM, EDXRA with SEM, transmission electron microscope (TEM), electron energy loss spectra with TEM, high-resolution transmission electron microscope (HRTEM) and microanalysis with HRTEM. The mineralogy of the rhizosphere differed from that of the bulk soil. Within the rhizosphere, minute platy particles which were mostly vermiculitic minerals, were particularly concentrated near or on root surfaces. These platy mineral particles were not attached to the entire area, but only to certain areas of root surfaces. Therefore, we report quantitative evidence for mineralogical changes in the rhizosphere in soil environments.

Key Words: Corn • Mineralogy • Non-rhizosphere • Rhizosphere

Clays and Clay Minerals; December 1994 v. 42; no. 6; p. 755-763; DOI: 10.1346/CCMN.1994.0420612
© 1994, The Clay Minerals Society
Clay Minerals Society (www.clays.org)