Table 4. Changes in soil physicochemical characteristics under different fertilization treatments after celery harvest in January 2017 (the fifteenth-season).
Data are means ± S.E., n = 3. Different lowercase letters indicate significant differences among different treatments at the P < 0.05 level.
| Treatment | pH | EC (mS cm–1) | Bulk density (g cm–3) | SOC (g kg–1) | NO3−N (mg kg–1) | NH4+-N (mg kg–1) | Available P (mg kg–1) | Available K (mg kg–1) |
|---|---|---|---|---|---|---|---|---|
| 0N | 8.5 ± 0.0 a | 0.44 ± 0.01 b | 1.30 ± 0.03 ab | 12.8 ± 0.1 e | 13.6 ± 3.6 d | 5.0 ± 0.5 b | 126.5 ± 1.2 c | 542.3 ± 35.7 a |
| 100IN | 8.3 ± 0.0 b | 0.49 ± 0.01 a | 1.32 ± 0.04 a | 13.3 ± 0.3 d | 21.9 ± 2.1 c | 5.6 ± 0.2 ab | 119.2 ± 8.3 d | 532.8 ± 21.3 ab |
| 75IN/25ON | 8.5 ± 0.1 a | 0.39 ± 0.02 d | 1.30 ± 0.04 ab | 15.2 ± 0.4 c | 25.1 ± 2.2 bc | 6.2 ± 0.4 a | 127.6 ± 3.2 c | 499.8 ± 4.0 bc |
| 50IN/50ON | 8.5 ± 0.0 a | 0.39 ± 0.01 cd | 1.24 ± 0.04 bc | 17.6 ± 0.1 b | 28.4 ± 2.8 ab | 6.6 ± 0.5 a | 138.0 ± 5.3 b | 465.5 ± 12.5 cd |
| 25IN/75ON | 8.5 ± 0.0 a | 0.41 ± 0.00 c | 1.21 ± 0.04 c | 20.0 ± 0.1 a | 30.8 ± 2.3 a | 6.5 ± 1.0 a | 166.8 ± 5.1 a | 449.3 ± 18.9 d |
EC electrical conductivity, SOC soil organic carbon, NO3−-N nitrate nitrogen, NH4+-N ammonium nitrogen, P phosphorus, K potassium.