What are the effects of agricultural management on soil organic carbon in boreo-temperate systems?

Table 2 Variables (domains) assessed during critical appraisal of primary study validity

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 (<15 cm) single or multiple sampling	0
	Plough layer (0–25 cm) single or multiple sampling, or deep (>25 cm) single sampling	1
	Multiple deep sampling (>25 cm)	2

ISSN: 2047-2382