Table 2. Statistical parameters of the factors.
| Index | Data transformation | Mean | SD | Kurtosis | Skewness | Frequency distribution |
|---|---|---|---|---|---|---|
| pH | LOG | 0.74 | 0.22 | −0.8009 | 0.1735 | Normal distribution |
| SOM /g kg−1 | SQRT | 5.32 | 1.42 | −0.1249 | −0.1123 | Normal distribution |
| AN /mg kg−1 | LOG | 2.11 | 0.18 | 0.4997 | −0.3926 | Normal distribution |
| AP /mg kg−1 | SQRT | 9.03 | 3.34 | −0.4300 | 0.3361 | Normal distribution |
| AK /mg kg−1 | SQRT | 13.90 | 4.89 | −0.7209 | 0.0334 | Normal distribution |
Notes.
SOM, soil organic matter; AN, alkali-hydrolyzable N; AP, available P; AK, available K.