| Age | | Code list | Restoration age (number of growing seasons) of the field |
| Plot | | Physical quantity | Plot number- Each field contained 4 plots |
| Biomass | | Physical quantity | Belowground plant biomass, i.e. roots and rhizomes (g/m2) |
| Quality | | Physical quantity | C:N ratio of belowground plant biomass |
| MBC | | Physical quantity | Microbial biomass C (μg/g soil) |
| Surrogate | | Physical quantity | Surrogate recovery for correcting PLFA concentrations (%) |
| PLFA | | Physical quantity | Total PLFA biomass (nmol/g soil) |
| AMF | | Physical quantity | Arbuscular mycorrhizal fungi PLFA biomass (nmol/g soil) |
| FB | | Physical quantity | PLFA fungi:bacteria biomass ratio |