
TY  - JOUR
A1  - Moody, P. W. 
A1  - Yo, S. A. 
A1  - Aitken, R. L. 
T1  - Soil organic carbon, permanganate fractions, and the chemical properties of acidic soils
JF  - Soil Research
JO  - Soil Res.
Y1  - 1997
VL  - 35
IS  - 6
SP  - 1301
EP  - 1308
KW  - ECEC, pH buffer capacity, P sorption, variable charge soils, oxidisable carbon.
UR  - https://doi.org/10.1071/S97050 
N2  - Total organic carbon (TC) in 32 acidic surface (0&#8211;10 cm) soils was divided into 3 fractions (C1, C2, and C3) based on oxidisability by different strengths of KMnO4 (33 mM and 167 mM). With the methodology used, ease of oxidation decreased in the order C1&#62;C2&#62;C3. Several fundamental soil chemical properties were also determined, i.e. ECEC, CEC at pH 6&#183;5 (CEC6&#183;5), slope of the charge curve (&#916;CEC), pH buffer capacity, (pHBC), P sorption capacity using a single addition index (PSI150), and content of organically complexed Al. All soils had pH (1:5 water) &#60;6&#183;5, and comprised a wide range of soil types and clay contents. Multiple step-up regression indicated that C fractions were significantly (P &#60; 0&#183;05) correlated with ECEC, &#916;CEC, CEC6&#183;5, and pHBC. These results reinforce the critical importance of soil organic matter to the fundamental soil chemical properties of predominantly variable charge soils. The intercorrelations between the various oxidisable C fractions made it difficult to elucidate if degree of oxidisability had any bearing on the reactivity of the organic matter. ECEC was primarily correlated with C1, whereas all C fractions had highly significant (P &#60; 0&#183;01) effects on &#916;CEC and pHBC. The fraction which was most difficult to oxidise, C3, made a significant (P &#60; 0&#183;01) contribution to CEC6&#183;5 when combined with clay and ECEC in a multiple regression equation. Generally, one or other of the C fractions was better correlated with the fundamental soil chemical properties than TC. This simple empirical fractionation of soil organic C may therefore be a useful tool for assessing the effects of soil management on these properties. 
ER  -

