Table 1 Critical appraisal criteria
From: How does tillage intensity affect soil organic carbon? A systematic review protocol
Variable | Value | Score |
|---|---|---|
Spatial (true) replication | 2 replicates | 0 |
3–4 replicates | 1 | |
>4 replicates | 2 | |
Temporal replication | ≤3 replicates | 0 |
4–6 replicates | 1 | |
>6 replicates | 2 | |
Treatment allocation (as described for the full experimental design) | Purposive (selective) | 0 |
Split-/strip-plot/latin square/blocked/randomised/exhaustive | 2 | |
Duration of experiment | 10–19 years | 0 |
20–29 years | 1 | |
≥30 years | 2 | |
Soil sampling depth | Shallow (maximum depth ≤15 cm) single or multiple sampling | 0 |
Plough layer (maximum depth 15–25 cm) single or multiple sampling, or deep (maximum depth >25 cm) single sampling | 1 | |
Multiple deep sampling (maximum depth >25 cm) | 2 |