3.3.Average well color development
During cultivation, the increase rate of AWCD slowed down after 5 days
(Fig. 2); AWCD peaked on day 8 and was stable afterwards. Among the
eight treatments, ANE showed the highest metabolic rate; the AWCD of ANE
increased from 0 to around 1.37 after 8 days. Treatment MN0 showed the
lowest metabolic rate, and AWCD increased to around 1.13, indicating a
less efficient carbon substrate use. This shows that incubation time has
an effect on microbial activity in the examined systems. In the stable
period, there were significant differences in the AWCD among the
microbial communities from alfalfa treatments (P <
0.01), following the order ANE > AE > AN0
> A0, suggesting that with increasing incubation time, the
metabolic activity of the alfalfa microbial community also increases. We
observed significant differences in AWCD among the microbial communities
of the mulberry treatments (P < 0.01), following the
order ME > M0 > MNE > MN0. The
AWCD in the treatments ME, M0 and MNE was increased by 23.8% (P< 0.01),21.5% (P < 0.01), and 19.04%
(P < 0.01), respectively, compared to MN0.