Table 2. The potential pool of soil organic carbon (SOC) and nitrogen (N) mineralized in different particle-size fractions from the control (CK) or soil that received 32 years of chemical fertilizer application (N, P: phosphorus, K: potassium) and either 0 (M0), 30(M30) or 60 (M60) t manure ha-1 yr-1 (mg kg-1 soil).
| Treatment | SOC mineralization | Soil N mineralization | ||||
|---|---|---|---|---|---|---|
| 2000–250 μm | 250–53 μm | <53 μm | 2000–250 μm | 250–53 μm | <53 μm | |
| CK | ||||||
| M0 | 30.5bc | 27.1abcd | 8.5e | 1.1bc | 1.2abc | 0.9cd |
| M30 | 25.9bc | 36.3abc | 34.0bc | 2.5bc | 5.7a | 6.6abc |
| M60 | 24.1c | 43.9a | 34.6bc | 2.4bc | 3.5abc | 2.5cd |
| N | ||||||
| M0 | 23.9c | 26.6abcd | 20.6cde | 1.5bc | - 1.2c | 3.1bcd |
| M30 | 42.2ab | 24.5bcd | 28.3bcd | 7.7a | 5.8a | 4.7abcd |
| M60 | 48.6a | 34.1abc | 38.7b | 5.2ab | 1.2abc | 6.2abcd |
| NPK | ||||||
| M0 | 23.1c | 22.3cd | 19.0de | - 0.7c | - 0.6bc | 0.5d |
| M30 | 29.1bc | 13.6d | 16.7de | 3.9ab | 4.7ab | 8.7ab |
| M60 | 29.6bc | 42.3ab | 59.1a | 1.7bc | 6.3a | 9.5a |
| Average a | 33.3 | 32.5 | 35.2 | 3.9 | 4.5 | 6.4 |
Note: Different letters indicate significant differences at 5% probability level within the same particle-size fraction.
a the average represent manure treatments.