3.3 SOC decomposition and NCB
N and P additions differently affected SOC mineralization and NCB
(Figure 3). Specifically, with glucose amendment SOC mineralization
increased by 33% under P addition while decreased by 9%, and 7% under
N, and NP addition, respectively (Figure 3a). SOC mineralization was
significantly correlated with soil C:P, N:P, and microbial C:N, C:P and
N:P (Table 2). When vanillin was amended, SOC mineralization was
increased by 7% and 8% under P and NP addition but decreased by 11%
under N addition (Figure 3a). SOC mineralization was significantly
correlated with soil and microbial C:N, C:P, N:P (Table 2).
The NCB were positive for all nutrient treatments regardless of glucose
or vanillin was amended (Figure 3b). Compared with control, the NCB with
glucose amendment were increased by 7% and 6% under N and NP
additions, respectively, while decreased by 40% under P addition. The
NCB with vanillin amendment was increased by 17% under N addition but
decreased by 36% and 42% under P and NP addition, respectively (Figure
3b).