2.7.1. Average well color development
The average well color development (AWCD) is calculated to
reflect the single carbon utilization of soil microorganisms [10]:
AWCD = Σ(Ci-R) 31
Here Ci is the absorbance of NO. i well and R is the absorbance of
the control well. When Ci-R < 0, the value is considered to be 0. That
is, Ci-R ≥ 0.
2.7.2. Soil microbial community functional diversity indexes
Shannon indices (H), Simpson indices (D) and McIntosh indices
(U) according to the following equations [11]:
H = −ΣPi × lnPi.
D = 1− Σ(Pi)2
U = (ΣNi2 )
Here Pi = (Ci-R)/Σ(Ci-R), is the ratio between the absorbance of one
well and total the absorbance of all wells. Ni = Ci-R, is the relative
absorbance of each well.
All the calculations were performed using the data at 96 h.