Table 2. Richness and diversity indices of microbial communities of alfalfa.
Operational taxonomic units (OTU). The Shannon index illustrates the heterogeneity of microbial communities; the Ace index is used to estimate the OTU number of in a community, indicating the richness of the microbial community; the Chao index is used to assess the total number and richness of species in a community.
| Samples | OTU number | Shannon | Ace | Chao | Coverage |
|---|---|---|---|---|---|
| CK | 154 | 2.8 | 146.66 | 139.79 | 0.99 |
| Mild | 173 | 2.35 | 161.89 | 158.27 | 0.99 |
| Moderate | 147 | 2.1 | 138.61 | 159.24 | 0.99 |
| Severe | 130 | 2.54 | 119.03 | 113.36 | 0.99 |
Notes.
- OTU
- Operational taxonomic units