Table 4. Semi-variance function theory model and parameters of soil nutrients.
| Index | Model | Main variation/km | Variation /km | ARC | Azimuth | C0 | C0+C | C0/(C0+C) | MSE |
|---|---|---|---|---|---|---|---|---|---|
| pH | Gaussian | 0.1390 | 0.0886 | 1.5689 | 136.5820 | 0.0225 | 0.0301 | 74.75% | −0.0211 |
| SOM/g kg−1 | J-Bessel | 0.0100 | 0.0168 | 1.6884 | 85.4297 | 5.7297 | 10.5931 | 54.09% | −0.0054 |
| AN/mg kg−1 | J-Bessel | 0.0138 | 0.0155 | 1.1198 | 169.2773 | 0.1031 | 0.1625 | 63.46% | −0.0308 |
| AP /mg kg−1 | Gaussian | 0.0056 | 0.0034 | 1.6486 | 159.2578 | 28.9266 | 46.4726 | 62.24% | 0.0031 |
| AK /mg kg−1 | J-Bessel | 0.0615 | 0.0397 | 1.5476 | 78.9258 | 61.9723 | 76.1515 | 81.38% | −0.0168 |
Notes.
ARC, anisotropy ratio coefficient; C0, the nugget; C0+C, abutment value; MSE, normalized mean error.