3.2. Molecular index of SOC stability
Fourier–transform infrared (FTIR)
spectroscopy of three soils generally featured common peaks but showed
different intensities (Fig. S2). The rA1635 of BF+ soil was
significantly lower than that of OF soil, and the order of the rA2930 of
the three soils was OF > BF > BF+ (P< 0.05, Fig. 2a, b and Table S1). The order of the resistance
index (ratio of rA1635/rA2930) of the three soils was BF+ >
BF > OF (P < 0.05, Fig. 2c). The trend of
resistance index (rA1635/rA2930) indicated that
the molecular index of SOC
stability (or resistance) was highest in BF+ soil, followed by BF soil,
and finally OF soil.