Premium
Distribution of allophane and organic matter in podzol B horizons: reply to Buurman & Van Reeuwijk
Author(s) -
FARMER V.C.
Publication year - 1984
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1984.tb00302.x
Subject(s) - allophane , podzol , organic matter , silicate , decomposition , horizon , chemistry , imogolite , mineralogy , geology , clay minerals , soil water , soil science , physics , organic chemistry , astronomy
SUMMARY The macromorphology, micromorphology and chemical nature of illuvial material in podzol B horizons and subsoils can be explained by contributions from two different migrating species: (a) a positively‐charged mixed Al 2 O 3 ‐Fe 2 O 3 ‐SiO 2 ‐H 2 O sol incorporating minor amounts of adsorbed organic matter and silicate clay, and (b) negatively charged organic sols and solutions, carrying minor amounts of Al, Fe and clay. These species can also be generated within B horizons of high root activity. An alternative theory, that requires allophane to be formed in situ in the B horizon by microbial decomposition of precipitated organic complexes, fails to predict the observed distribution of allophane.