TY - JOUR

T1 - Regularities of extracting humic acids from soils using sodium pyrophosphate solutions

AU - Bakina, L. G.

AU - Drichko, V. F.

AU - Orlova, N. E.

PY - 2017/2/1

Y1 - 2017/2/1

N2 - Regularities of extracting humic acids from different soil types (soddy-podzolic soil, gray forest soil, and all chernozem subtypes) with sodium pyrophosphate solutions at different pH values (from 5 to 13) have been studied. It is found that, regardless of soil type, the process occurs in two stages through the dissociation of carboxylic groups and phenolic hydroxyls, each of which can be described by a logistic function. Parameters of the logistic equations approximating the extraction of humic acids from soils at different pH values are independent of the content and composition of humus in soils. Changes in the optical density of humic acids extracted from soils using sodium pyrophosphate solutions with different pH values are described in the first approximation by the Gaussian function. The optically densest humic acids are extracted using sodium pyrophosphate solutions at pH 10. Therefore, it is proposed to use an extract with pH 10 for the characterization of organic matter with the maximum possible degree of humification in the given soil.

AB - Regularities of extracting humic acids from different soil types (soddy-podzolic soil, gray forest soil, and all chernozem subtypes) with sodium pyrophosphate solutions at different pH values (from 5 to 13) have been studied. It is found that, regardless of soil type, the process occurs in two stages through the dissociation of carboxylic groups and phenolic hydroxyls, each of which can be described by a logistic function. Parameters of the logistic equations approximating the extraction of humic acids from soils at different pH values are independent of the content and composition of humus in soils. Changes in the optical density of humic acids extracted from soils using sodium pyrophosphate solutions with different pH values are described in the first approximation by the Gaussian function. The optically densest humic acids are extracted using sodium pyrophosphate solutions at pH 10. Therefore, it is proposed to use an extract with pH 10 for the characterization of organic matter with the maximum possible degree of humification in the given soil.

KW - Greyzemic Phaeozem

KW - Haplic Chernozems (Pachic)

KW - humic acids

KW - organic matter

KW - Umbric Retisols (Abruptic)

UR - http://www.scopus.com/inward/record.url?scp=85014706234&partnerID=8YFLogxK

U2 - 10.1134/S1064229316120036

DO - 10.1134/S1064229316120036

M3 - Article

AN - SCOPUS:85014706234

VL - 50

SP - 210

EP - 217

JO - Eurasian Soil Science

JF - Eurasian Soil Science

SN - 1064-2293

IS - 2

ER -