Table 2. Soil organic carbon (SOC), inorganic carbon (SIC) stocks and the SIC:SOC ratio in typical croplands of North China.
| Region | The annual precipitation (mm) | Soil types | pH | SOC stock (kg C m−2) |
SIC stock (kg C m−2) |
The SIC/SOC ratio |
Reference | |||
|---|---|---|---|---|---|---|---|---|---|---|
| 0–30 cm | 30–100 cm | 0–30 cm | 30–100 cm | 0–30 cm | 0–100 cm | |||||
| Yanqi (n = 9) | 80 | Brown Desert Soil | 8.2 | 4.53 ± 0.52 | 4.38 ± 1.69 | 11.07 ± 1.45 | 31.3 ± 7.42 | 2.44 | 4.72 | Wang et al.15 |
| Urumqi (n = 5)* | 299 | Gray Desert Soil | 8.1 | 4.25 ± 1.49 | 4.90 ± 0.65 | 2.03 ± 0.31 | 3.38 ± 0.77 | 0.48 | 0.59 | Wang et al.8 |
| Lanzhou (n = 33) | 300 | Loess Soil | 8.9 | 2.46 ± 0.74 | 3.64 ± 1.44 | 6.24 ± 0.99 | 14.54 ± 2.39 | 2.54 | 3.41 | Zhang et al.22 |
| Yangling (n = 5)* | 585 | Manural Loess Soil | 8.6 | 4.16 ± 0.93 | 5.18 ± 0.26 | 3.94 ± 0.27 | 5.06 ± 0.19 | 0.95 | 0.96 | Wang et al.8 |
| Zhengzhou (n = 5)* | 641 | Fluvo-aquic Soil | 8.3 | 3.29 ± 0.59 | 3.31 ± 0.28 | 2.95 ± 0.08 | 5.19 ± 0.39 | 0.9 | 1.27 | Wang et al.8 |
| Zibo-Binzhou (n = 31) | 600 | Fluvo-aquic Soil | 8.2 | 2.70 ± 0.64 | 3.03 ± 0.64 | 4.06 ± 0.81 | 12.83 ± 2.80 | 1.50 | 2.95 | This study |
*Each site collected in 2002 and 2009 with three replicates.