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Table 1 List and description of meta-data variables extracted during coding

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

Meta-data Description
Title Source article title
Authors Source article authors
Journal Source article journal
Year Source article publication year
Volume Source publication volume
Page start–page end Source publication pages (start page to end page)
Author E-mail Source article corresponding author contact email address
Study country Country in which study was undertaken
Location site/name Name or location of study site
Latitude Latitude cited within article (converted to decimal degrees)
Longitude Longitude cited within article (converted to decimal degrees)
Köppen climate zone Stated climate zone (according to [39]) or established from latitude and longitude using Köppen Climate Zone GIS layer
Reference to Previous articles Stated reference to previously published work regarding experimental design: likely source of missing information
Study ID Reviewer-assigned study identification code
Soil texture, % Clay Stated soil clay content (per cent) or stated soil type
Soil Texture, % Silt Stated soil silt content (per cent)
Soil texture, % sand Stated soil sand content (per cent)
Intervention, start Intervention start date (year)
Intervention, end Intervention end date (year) or soil sampling date (year)
Duration of intervention, years Time period intervention was in place before sampling (years)
Intervention Intervention category (see Coding Framework for details of included sub-categories) (crop rotation/fertiliser/amendments/catch crop/tillage/multiple/farming system)
Number of treatments Total number of treatment and control groups
Which treatments Stated treatment groups (either by intervention group when factorial designs or stated individual intervention combinations)
Crop Crop type (annual, perennial, single crop, double crop)
Study Design Design of the comparison within the study (Before-after/comparator-intervention/before-after-comparator-intervention)
Comparator type Stated comparator
Experimental design Stated design of the experiment (Randomised complete block/split-plot/time series/etc.)
Level of replication Level at which true replication was undertaken
Dimension of plots Plot (subplot) dimensions (metres or hectares)
Number of spatial replicates Number of true spatial replicates per treatment group
Temporal replicates Number of temporal replicates (repeated measures)
Sampling precision Number and type of pseudoreplicates (within true replicate sampling)
Soil sampling depth Soil sampling depth categories for which data are provided independently
C measurement method Carbon quantification method
Outcome Type of outcome measured (SOC/TOC/SOM/TC/OC)
Unit Units of measurement
Data location Location of relevant outcome data within the article
Bulk density Presence of bulk density measurements (Measured/Calculated/Not Present)
Variance presented Presence and location of variance relating to true replication (standard deviation, standard error or confidence interval). Description of ‘next best variance’ if no true replicate variance reported