From: How does tillage intensity affect soil organic carbon? A systematic review
Tillage comparison | Soil depth (cm) | Summary effect estimate (Mg/ha) | Standard error | z statistic | p value | Lower 95% confidence interval | Upper 95% confidence interval | Number of studies |
---|---|---|---|---|---|---|---|---|
NT–HT | Upper layer | 4.606 | 1.954 | 2.357 | 0.018 | 0.776 | 8.435 | 29 |
 | Full profile | 1.646 | 3.409 | 0.483 | 0.629 | − 5.035 | 8.327 | 14 |
NT–IT | Upper layer | 3.852 | 1.644 | 2.343 | 0.019 | 0.630 | 7.075 | 32 |
 | Full profile | 0.831 | 2.711 | 0.306 | 0.759 | − 4.483 | 6.144 | 13 |
IT–HT | Upper layer | 1.724 | 0.952 | 1.811 | 0.070 | − 0.142 | 3.589 | 29 |
 | Full profile | 1.883 | 2.529 | 0.745 | 0.457 | − 3.074 | 6.840 | 10 |