Humus Fraction Ratios as a Means of Discriminating Between Horizon Types

Abstract

Lows, L. E. 1980. Humus fraction ratios as a means of discriminating between horizon types. Can. J. Soil Sci. 60: 219-229.Humus fraction distribution in a wide range of horizon samples was examined by measuring carbon content in humic acid (C1), in fulvic acid (C) and in the strongly colored polyphenolic component of the fulvic acid fraction (Cn). Fraction distribution was described by the ratios C6/C1 and C"/Ci. It was concluded that humus fraction ratios were related to horizon types as used in the Canadian System ofSoil Classification, and were effective in discriminating between certain horizon types, particularly between Luvisolic Bt and Podzolic Bf. The

Characteristics of humic substances and dynamics of dissolved organic matter in forest soils in northern Kyoto with special reference to their pedogenetic processes

“…According to the procedure, the soil humic substances were fractionated into humic (Ch) and fulvic (Cf) acids, and the latter was further divided into a polyvinylpolypyrrolidone-adsorbed fraction (Ca; consisting of polyphenolic acids) and a non-adsorbed fraction (consisting of polysaccharides). In all the B horizons, the characteristics of the humic substances were specific to the podzolic B horizon, that is, the Ch/C~ ratios were below 0.4 and the Ca/Cf ratios were above 0.3 (Lowe 1980;Schuppli and McKeague 1984), regardless of soil or vegetation types.…”

“…Characteristics of humic substances from the soils, soil solutions, and litter extracts 1) Fractionation of soil humic substances. Characteristics of humic substances after the fractionation scheme proposed by Lowe (1980) are given in Table 2. According to the procedure, the soil humic substances were fractionated into humic (Ch) and fulvic (Cf) acids, and the latter was further divided into a polyvinylpolypyrrolidone-adsorbed fraction (Ca; consisting of polyphenolic acids) and a non-adsorbed fraction (consisting of polysaccharides).…”

A comparison of two methods for routine characterization of humus in pedological studies

“…• While the methods are essentially those described by LoWE (1980) and KUMADA et al (1967), minor modifications and more complete technical details are presented here.…”

“…LoWE (1980) demonstrated that the determination of CalCr together with ChlCr was effective in discriminating between certain horizon types, particularly between Luvisolic Bt and Podzolic Bf. He also suggested that humus fraction ratios may be effective in separating distinct sub-populations within Ah horizons and Bf horizons in general, based on qualitative differences in the organic matter present.…”

Water Retention Equations and Their Relationship to Soil Organic Matter and Particle Size Distribution for Disturbed Samples

“…However, these equations might not be applicable to other parts of the province because there is evidence (Lowe 1969(Lowe , 1980 that the nature of the soil organic matter changes from one soil zone to the next.…”