| Total C (mg∙kg−1) | Total N (mg∙kg−1) | Total P (mg∙kg−1) | Total K (mg∙kg−1) | C/N ratio | NO− 3-N (mg∙kg−1) | NH+ 4-N (mg∙kg−1) | Available phosphoric acid (mg∙kg−1) | Exchangeable potassium (mg∙kg−1) | pH | EC (mS∙cm−1) | ||
| Black soil | 59,520 ± 8.16z | 2692 ± 0.12 | 677 ± 1.63 | 1106 ± 2.45 | 22.1 ± 0.08 | 9.0 ± 0.8 | 0 ± 0.0 | 12.0 ± 2.45 | 57 ± 1.63 | 5.5 ± 0.1 | 0.14 ± 0.02 |