Mechanism of Interaction between Earthworms and Root Parameters on Cambisol

Plants respond to their environment through adaptations; for example, earthworms that create heterogeneity can lead to local adaptation of roots. This research identifies a mechanism to explain plant responses to earthworms and how these mechanisms are related. Our results show that tillage intensity has a negative effect on earthworms and root volume. The mean root volume and earthworm biomass under conventional tillage were lower than in reduced tillage and no-tillage. The root volume and the root diameter in the field with residues were higher than in the field without residues, while the root length density and earthworm biomass in the field with residues were lower than in the field without residues. This study demonstrates that the mean of the root length density and biomass of the earthworms were higher in sandy loam than in loam. Therefore, sand content had a positive effect on root length density (R² = 0.72, p < 0.01) and earthworm biomass (R² = 0.74, p < 0.01). Earthworm biomass had a positive effect on root volume (R² = 0.54, p < 0.05) and length density (R² = 0.88, p < 0.01). This confirms our hypothesis on the effect of earthworms on root systems.