The AWCD values were the highest both in the T1 treatment in soil A and soil B.
Different fertilization had different effects on carbon source utilization ability of soil microbial community and AWCD could be used to characterize the level of utilization rate of carbon source.
The results showed that the classification similar to disease index of various treatments and it coincided with the number of microorganisms and AWCD values.
Some studies revealed that the soils under conventional tillage had lower AWCD and H values than those under reduced tillage (Giller 1996; Lupwayi et al.
The AWCD value each well in the EcoPlate is an important index that reflects the soil microbial community functional diversity (Yang and Hua 2000).
2011), who reported significant positive correlations between AWCD and H in soils under nine plant species (P<0.
The average well color development (AWCD) on the Biolog EcoPlateTM inoculated with soils collected from S3 was higher compared with those from other sampling sites however a large decrease in AWCD was observed on D2 and D3 (Fig.
PC 1 positively correlated with soil pH; PC 2, PC 3, AWCD and richness positively correlated with percent total carbon; PC 2, AWCD and richness positively correlated with percent total nitrogen, while PC 1 and richness negatively correlated with carbon to nitrogen ratio; PC 3 positively correlated with available phosphorus but negatively correlated with exchangeable calcium; PC 2, PC 3 and AWCD positively correlated with exchangeable potassium; and PC 3 had positive correlation with exchangeable sodium.
The decline of the microbial activity in the soil samples observed from D1 to D3 as indicated by AWCD, wherein the microbial activity for the three locations was lowest on D3, may be due to the very low plant and root activity during its dormancy period.
Table 5: Effects of soil conditioners on various principal components in flue-cured tobacco soil microorganisms with AWCD
The logistic curve (Eqn 2) was fitted to the AWCD data for each soil and the values for various parameters are shown in Table 3.
One-way ANOVA of the AWCD values showed that the Brinsley, Catombal, Robertson, and Windsor soils were significantly different from each other (l.