3.3 Microbial biomass and qCO2 responses
influenced by land management
According to the RM-ANOVA (Table 2), MBC was explained well by treatment
(83.9 %). The average MBC of each cultivation period was 84.5, 94.8,
103.2, and 103.0 mg C kg−1 (first-year), 87.3, 93.0,
117.1, and 113.3 mg C kg−1 (second-year), and 79.4,
87.3, 115.5, and 119.1 mg C kg−1 (third-year) in the
C, B, M and BM treatments, respectively (Fig. 2a-c and Table 3). In all
cultivation periods, there were no significant differences in MBC
between the C and B treatments, while MBC in the M and BM treatments
were significantly higher than that in the C and B treatments in most
cultivation periods.
In the first year, qCO2 tended to be high during the
first half of the cultivation period, whereas it was high during the
latter half of the cultivation period in the second year (Fig. 2d-e). In
the third year, qCO2 fluctuated over the whole
cultivation period (Fig. 2f). As for MBC, during all cultivation
periods, there were no significant differences in qCO2between the C and B treatments, while qCO2 in the M and
BM treatments were significantly higher than that in the C and B
treatments in most cultivation periods (Table 3). Only during the
cultivation period of the first year, qCO2 in the BM
treatment was significantly lower than that in the M treatment. During
the period when there was a significant difference in
qCO2 between the M and BM treatments (Fig. 2d),
qCO2 in the BM treatment (9.3–19.1 µg
CO2-C mg MBC−1 h−1)
was 30% lower than that in the M treatment (15.1–29.4 µg
CO2-C mg MBC−1 h−1),
while qCO2 in the M and BM treatments showed a similar
fluctuation during the second and third cultivation periods. As with the
CO2 efflux rate, a significant interaction effect
between biochar application and FYM application on qCO2was shown during the cultivation period of the first year (Table S2). In
the C treatment, the MBC was independent of soil moisture (data not
shown), while qCO2 was significantly correlated with
soil moisture (Fig. S2b).