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Surfaces of Peds from B Horizons of Illinois Soils
Author(s) -
Grossman R. B.,
Odell R. T.,
Beavers A. H.
Publication year - 1964
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1964.03615995002800060031x
Subject(s) - montmorillonite , soil water , moisture , chemistry , geology , mineralogy , soil science , environmental science , organic chemistry
Surfaces of peds from B horizons of several Illinois soils were studied. Concepts of “structural specific surface” and of “disparity” between the ped surface and ped interior are presented. The ped surfaces are described in terms of accretive (accumulation) and degradational (removal) alteration classes. Aspects of the moisture regime at the ped surface are discussed. Ped surfaces were sampled by washing kerosene‐saturated peds with Calgon solution. Clay in the ped surface generally has more fine clay (<0.04µ) and more coarse clay (>0.5µ) than clay from bulked (whole) peds. Collapse from 14Å to 10Å is less complete on heating to 450°C. for the clay from the ped surface. In samples of peds with significant percentages of both montmorillonite and nonexpanding 2:1 lattice clays, the predominantly accretive ped surfaces have more mortmorillonite than the bulked peds, whereas predominantly degradational ped surfaces have less.