Table 2 Percentage of stable soil carbon.

From: Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls

% Stable C

 

Chemically stable C

Biologically stable C

Kaolinite

 Glucose

37.39Aa

76.61Aa

 Cellobiose

37.37Aa

63.34Aa

 DOC

37.14Aa

74.13Aa

Montmorillonite

 Glucose

44.12ABa

82.76Aa

 Cellobiose

36.33Aa

87.65Bb

 Syringol

48.03Ba

93.42C

 DOC

38.65Aa

93.00Cb

Field soil

32–66*

77.60±3†

  1. Chemically stable SOC is the per cent of non-hydrolysable C, and biologically stable SOC is the per cent of previously accumulated SOC not mineralized during a 3-month incubation at 6 months. For comparison, natural field soil results are also presented. Significance among substrates within clay type is indicated by capital letters. Significant pair-wise comparisons among clay types within a substrate group are indicated by lowercase letters (ANOVA: P<0.05) (experimental replication n=5). DOC, dissolved organic C.
  2. *Range is the acid unhydrolysable fraction using 6 M HCl from 22 soils from cultivated and grassland soils at depths from 0 to 20, 25 to 50 and 50 to 100 cm (ref. 25).
  3. †Per cent of non-mineralizeable SOC from a 588 day laboratory incubation on eight cultivated and native grassland soils24.
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