Study Earthworm species Study type Charcoal/biochar description and application rate Location Soil/pH Earthworm impact Topoliantz and Ponge [45 ] Pontoscolex corethrurus L Char from slash-and-burn field 60% char mixture French Guiana Oxisol pH 4.6 inc 6.9 Normal growth rates; less casting and burrowing activity in char:soil mixtures; 1 of 10 earthworms died Topoliantz and Ponge [46 ] Pontoscolex corethrurus L Charred wood from slash-and-burn 60% char mixture French Guiana Oxisol PH 4.2–4.6 inc 6.9 Nonsignificant growth increases; direct charcoal consumption observed; surface cast production greater with soil : char mixture Topoliantz et al. [74 ] Pontoscolex corethrurus L “local homemade charcoal” no further description−2 mixture of organic amendment mounded and covered with soil French Guiana: (3°39′N; 54°2′W) Oxisol pH 4.4 inc 4.9 Decrease in abundance of juveniles not significant; decrease in number of cocoons significant (charcoal + saw dust only) Chan et al. [49 ] Earthworms, spp. not stated L Poultry litter
activation (pH 13) −1 Australia Alfisol pH 4.8–5.0 inc 6.0–7.8 Earthworms showed no preference/avoidance for soil over soil : char mixtures (specific data on char concentrations not provided); preference better for lower pH char Cui et al. [47 ] Eisenia fetida L Crop ash from burned rice residue China Sediment
No mortality, but genotoxicity (damage to earthworm DNA) occurred at ash concentrations of 10% Van Zwieten et al. [22 ] Eisenia fetida L Wood chip biochar Slow pyrolysis, 550°C 50 : 50 and 30 : 70 Paper pulp sludge to 10 t ha−1 Australia Ferrosol pH 4.2 inc’d to 5.9 Biochar : Ferrosol mixture preferred; no preference for biochar : Calcarosol mixture; biochar with 70% wood chips slightly more preferred over biochar with 50% wood chips Liesch et al. [12 ] Eisenia fetida L Poultry litter and pine chip biochars 400°C 30 min −1 US Simulated soil pH initially 7.0 Poultry litter biochar mortality and weight loss increased with application rate; Pine chip biochar no significant effect on mortality Li et al. [50 ] Eisenia fetida L Apple wood chips −1 US Simulated soil pH initially ~7.0 Avoidance of biochar amended soil—eliminated by wetting biochar; weight loss increasing with application rate Gomez-Eyles et al. [55 ] Eisenia fetida L Deciduous, hardwood-derived biochar; 600°C UK Contaminated soil, type not statedpH 7.63 Weight loss observed with biochar; reduced contaminant accumulation in body tissue Husk and Major [75 ] Earthworms spp. not stated F Hardwood waste material−1 Canada Soil type not stated; pH variable between 6.4–7.4 Generally higher abundance in biochar plots but not statistically compared Current study European lumbricids F Wood-derived biochar (
manure) by fast pyrolysis−1 US Waukagan silt loam; pH 6.3–6.6 No impact on field populations Haimi et al. [56 ] Cognettia sphagnetorum F Wood ash −1 Finland Forest soil (podzolized sandy soil) Decreased abundance following 2500 and 5000 kg ha−1 −1 Liiri et al. [58 ] Cognettia sphagnetorum L Wood ash 5000 kg ha−1 Finland Pine forest humus Decreased biomass but only when wood ash mixed into treated humus Liiri et al. [59 ] Cognettia sphagnetorum L Wood ash 5000 kg ha−1 Finland Pine forest humus pH 4.5 Decreased biomass Cox et al. [60 ] Earthworms; spp not stated F Coal ash110 t ha−1 US Naff silt loam No significant difference in total biomass or abundance Nieminen [61 ] Cognettia sphagnetorum L Wood ash Finland Norway Spruce forest humus pH 4.6 Decreases with solely wood ash
ash Lundkvist [89 ] Cognettia sphagnetorum L/F Wood ash Sweden Forest soil No significant differences Huhta et al. [90 ] Cognettia sphagnetorum F Wood ash Finland Forest soil Decreased biomass following ash addition; Controls lacked earthworms; few earthworms found where ash applied Lundkvist [62 ] Cognettia sphagnetorum; Earthworms species not statedF Wood ash
NH4 NO3 Sweden Forest soil No population effects; Increased Cd in body tissue; Increase in earthworm Nieminen [91 ] Cognettia sphagnetorum L Wood Ash (0.5 Mg ha−1 ) Finland Mineral soil pH 6 Wood ash reduced enchytraeid size, but no significant effect on total biomass Nieminen and Haimi [92 ] Cognettia sphagnetorum L Wood ash (birch ash) Finland Norway Spruce forest humus pH 4.6 Initially decreased body size; lower reproductive rates
