Table 3.
Soil organic carbon (SOC) stocks (Mg ha−1) in three soil layers (0–0.1, 0.1–0.2, 0.2–0.5 m) and total SOC stocks (0–0.5 m) sampled in 2014/2015. Total SOC stocks are given as sum of SOC stocks per soil layer and normalised to the total mean soil mass of CT plots by the equivalent soil mass approach (ESM) after Appel (2011). Means (SE, n = 4) are given per treatment and ANCOVA results mark significant differences between tillage and fertiliser systems. SOC concentrations and bulk densities are given in Table S3 in the Supplementary material.
| SOC stocks per soil layer |
total SOC stocks (0–0.5 m) |
||||
|---|---|---|---|---|---|
| Treatments | 0–0.1 m | 0.1–0.2 m | 0.2–0.5 m | sum | ESM corrected |
| CT-SL | 25.4 (1.4) | 26.8 (1.4) | 48.1 (5.8) | 100.3 (8.5) | 101.2 (10.9) |
| CT-MC | 28.2 (1.7) | 28.1 (1.7) | 50.3 (3.5) | 106.6 (5.8) | 107.9 (8.6) |
| RT-SL | 29.8 (1.0) | 29.2 (1.5) | 49.7 (3.9) | 108.7 (6.2) | 109.2 (8.0) |
| RT-MC | 31.2 (0.9) | 28.8 (1.7) | 47.8 (3.6) | 107.8 (6.0) | 109.3 (8.4) |
| ANCOVA (F-Statistics and significance levels) | |||||
| Clay content | 3.2 × 1010*** | 231.7 *** | 147.9 *** | 277.0 *** | 193.1 *** |
| Tillage | 4.8 × 108*** | 4.0 (*) | 11.0 ** | 1.8 ns | 0.4 ns |
| Fertilisation | 1.4 × 109*** | 18.4 ** | 3.1 ns | 1.1 ns | 1.9 ns |
| Tillage x Fert. | 2.2 × 102*** | 17.2 ** | 3.1 ns | 8.5 * | 6.2 * |
Treatments: CT – ploughing, RT – reduced tillage, SL – slurry, MC – manure compost. ns = not significant.
(*)p < 0.1. *p < 0.05. **p < 0.01. ***p < 0.001.