From: How does tillage intensity affect soil organic carbon? A systematic review
Tillage comparison | Soil depth (cm) | Summary effect estimate (g/kg) | Standard error | z statistic | p value | Lower 95% confidence interval | Upper 95% confidence interval | Number of studies |
---|---|---|---|---|---|---|---|---|
NT–HT | 0–15 | 2.086 | 0.344 | 6.073 | < 0.001 | 1.413 | 2.760 | 102 |
15–30 | − 0.298 | 0.286 | − 1.039 | 0.299 | − 0.859 | 0.264 | 49 | |
> 30 | − 0.371 | 0.261 | − 1.424 | 0.155 | − 0.882 | 0.134 | 31 | |
NT–IT | 0–15 | 1.179 | 0.334 | 3.537 | < 0.001 | 0.526 | 1.833 | 95 |
15–30 | 0.273 | 0.289 | 0.944 | 0.345 | − 0.293 | 0.839 | 45 | |
> 30 | − 0.157 | 0.186 | − 0.845 | 0.398 | − 0.522 | 0.208 | 20 | |
IT–HT | 0–15 | 1.229 | 0.221 | 5.575 | < 0.001 | 0.797 | 1.662 | 77 |
15–30 | − 0.890 | 0.198 | − 4.539 | < 0.001 | − 1.288 | − 0.511 | 42 | |
> 30 | − 0.261 | 0.209 | − 1.250 | 0.211 | − 0.671 | 0.148 | 16 |