Descriptions of the information in each column in the database The columns of the database were grouped by sections: Publication (information about the journal article or study from which the data was collected), Data (the variable measured, units, means, errors, and replicates of each study), Home Plants (qualifiers describing information about the home or focal plant species in the study), Away Plants (qualifiers describing information about the away or heterospecific plant species in the study), Soil (qualifiers describing the soil used in the study), and Herbivores (qualifiers describing information about the herbivores used in the study). The database starts with the unique observation number assigned to each study (Column A), the DOI (Column B) for the paper from which the data was collected, the unique publication number assigned to each included publication (Column F), the research group from which the publication originated (Column D), and whether the study contained data for the plant (yes or no) and the insect (yes or no). All studies contained plant data, but not all studies contained insect data. Plant Data: In Column G we listed the plant variable measured (total dry weight, aboveground dry weight, aboveground fresh weight, or plant height). In Columns H-R we recorded the following data variables regarding the plants in the study including the unit of the measurement (e.g., g) (H), type of reported variance (se=standard error and sd=standard deviation) (I), number of replicates (J), mean without herbivory in home soil (K), mean without herbivory in away soil (L), mean with herbivory in home soil (M), mean with herbivory in away soil (N), variance for mean without herbivory in home soil (O), variance for mean without herbivory in away soil (P), variance for mean with herbivory in home soil (Q), variance for mean with herbivory in away soil (R). Herbivore Data: In Column S we listed the insect variable measured (population size, biomass, or fecundity). In Columns T-Z we recorded the following data variables regarding the insects in the study including the unit of the measurement (e.g., g) (T), type of reported variance (se=standard error and sd=standard deviation) (U), mean for herbivores that fed on plants in home soil (V), mean for herbivores that fed on plants in away soil (W), variance for mean in home soil (X), variance for mean biomass in away soil (Y), and number of replicates (Z). Consumption Data: In Column AA we listed the damage variable measured (biomass lost or surface area), in Column AB we recorded the damage unit (percentage of biomass loss or mm2), and in Column AC we recorded the type of reported variance (se=standard error and sd=standard deviation). In Columns AD-AH we recorded the mean consumption/damage on home plants (AD), mean consumptions/damage on away plants (AE), variance for mean on home plants (AF), variance for mean on away plants (AG), and number of replicates (AH). Home Plants: In this section we provide meta-data about the “home” plants in the plant-soil feedback studies. We include the species name (Column AI); plant family (Column AJ); whether the plant is a crop or not (Functional Type 1) (Column AK); whether the plant is annual, perennial, or biennial (Functional Type 2) (Column AL); whether the plant is a grass, forb, or woody (Functional Type 3) (Column AM), whether plant is a legume (yes or no) (Column AN); whether the carbon metabolism of the plant is C3 vs C4 (Column AO); whether the plant is native, invasive, or non-native/range expanding in the environment in which the study was conducted (Home Plant Locality) (Column AP); and the source of the plant (e.g., known cultivars) (Home Source) (Column AQ). Away Plants: In this section we provide meta-data about the “away” plants in the plant-soil feedback studies. We include whether the “away” soil was cultured by an individual species or a mix of species (Column AR); the species name (Column AS); plant family (Column AT); whether the plant is a crop or not (Functional Type 1) (Column AU); whether the plant is annual, perennial, or biennial (Functional Type 2) (Column AV); whether the plant is a grass, forb, or woody (Functional Type 3) (Column AW), whether plant is a legume (yes or no) (Column AX); whether the carbon metabolism of the plant is C3 vs C4 (Column AY); whether the plant is native, invasive, or non-native/range expanding in the environment in which the study was conducted (Home Plant Locality) (Column AZ); and the source of the plant (e.g., known cultivars) (Home Source) (Column BA). Soil: In this section we provide meta-data on the soil used in the analyzed studies. We include soil type if reported (clay, silty clay, sandy clay, clay loam, silty clay loam, sandy clay loam, loam, silt loam, silt, sandy loam, loamy sand, sand, or not reported) (Column BB); the type of habitat the soil was collected from (grassland, agriculture, forest, and urban) (Column BC); the topography, if reported, the soil was collected from (hills, mountainous, flat, aquatic) (Column BD); the country where the soil was collected (Column BE); and whether the soil was pre- conditioned in the lab or the field (Soil Precondition) (Column BF). Herbivore: In this section we provide meta-data about the herbivore in the studies. We include the herbivore species name or whether a mix of species was used (Column BG); herbivore family (or mix of species) (Column BH); the herbivore feeding strategy (chewing, sucking, galling, mining, or other) (Column BI); what phylum did the herbivore belong to (insect, nematode, gastropod, or artificial) (Column BJ); where the herbivore lives (Herbivore Position) (above or belowground) (Column BK); what plant structures the herbivore eats (e.g., leaf, stem, root) (Herbivore Plant Part) (Column BL); and whether the herbivore is native or invasive in the environment in which the study was conducted (Herbivore Locality) (Column BM).