Soil properties and early ryegrass growth following mycorrhizal inoculum and earthworm addition

Pots contained 2.80 kg air-dried soil and were maintained at 65–70% estimated field capacity. Pot positions were randomly reassigned every 7 days. The archive provides pot-level measurements of bulk density, particle density, total porosity, gravimetric water content, estimated field capacity, pH, electrical conductivity, organic matter, available nitrogen, phosphorus, and potassium, as well as ryegrass height, adventitious-root length, biomass, and root-to-shoot ratio.

It also includes paired soil-core data, earthworm recovery and survival records, AMF root-colonisation observations, one-way ANOVA and Tukey HSD outputs, factorial ANOVA outputs, and Python scripts used to reproduce derived indices and figures. The data show that AMF, earthworms, and their combination produced distinct soil–plant response patterns. The AMF+EW treatment had the lowest bulk density and the highest total porosity, while AMF inoculation increased soil water content, estimated field capacity, available phosphorus, and available potassium.

The combined treatment generally produced the highest ryegrass height and root length. These results can be interpreted as short-term, pot-scale responses of urban construction soil to biological soil amendments; they should be used within the experimental conditions described above. The archive also contains an independent temperature-gradient dataset covering six temperatures (4, 0, −5, −10, −15, and −20 °C), with four biological replicates per temperature level.

These data support supplementary quadratic-regression analyses of plant growth, soil properties, relative electrical conductivity, and malondialdehyde responses. The corresponding regression tables, residual-diagnostic file, and reproducible Python code are included for transparent reanalysis.