Soil physical and chemical properties (means ± SE) under the different density <i>Eisenia fetida</i> and <i>Metaphire guillelmi</i> addition treatments (n = 15).

Soil physical and chemical properties (means ± SE) under the different density Eisenia fetida and Metaphire guillelmi addition treatments (n = 15).</p

The body length (cm), width (cm), Gizzard diameter (cm), Foregut length (cm), Midgut length (cm), and Hindgut length (cm) of two earthworm species (<i>Eisenia fetida</i>, <i>Metaphire guillelmi</i>).

The body length (cm), width (cm), Gizzard diameter (cm), Foregut length (cm), Midgut length (cm), and Hindgut length (cm) of two earthworm species (Eisenia fetida, Metaphire guillelmi).</p

Structural equation models showing the feeding relationship in the food web (soil microorganism, and soil nematode communities) in response to the addition of the different density earthworms (<i>Metaphire guillelmi</i>) (n = 60) (χ² = 55.998, df = 64, P = 0.919, CFI = 1.000, GFI = 0.889, RMSEA = 0.000).

Numbers on arrows are standardized path coefficients. Solid arrows suggested the effects were significant (P 0.05). BG, the belowground biomasses of winter wheat.</p

Fig 2 -

The biomass of soil total microorganism (a), bacteria (b), fungi (c), gram-negative bacteria (d), gram-positive bacteria (e), actinomycetes (f), AMF (arbuscular mycorrhizal fungi) (g), and protozoa (h) under two earthworm species (Eisenia fetida, Metaphire guillelmi), and the different density of Eisenia fetida and Metaphire guillelmi treatments. C, control (no added earthworm); +1E1, +2E1, and +4E1 represents added 1, 2, and 4 Eisenia fetida earthworm individuals, respectively; +1E2, +2E2, and +4E2 represents added 1, 2, and 4 Metaphire guillelmi earthworm individuals, respectively. Different uppercase letters indicate significant difference in different earthworm species. Different lowercase letters indicate significant difference in different density under each earthworm species, relative to the control treatments (replicates = 15).</p

The soil microorganisms, soil nematodes, and soil physicochemical properties under two earthworm species (<i>Eisenia fetida</i>, <i>Metaphire guillelmi</i>), and the different density of <i>Eisenia fetida</i> and <i>Metaphire guillelmi</i> treatments.

The soil microorganisms, soil nematodes, and soil physicochemical properties under two earthworm species (Eisenia fetida, Metaphire guillelmi), and the different density of Eisenia fetida and Metaphire guillelmi treatments.</p

The physical indices (Mean ± se) of two earthworm species including <i>Eisenia fetida</i> (105 individuals) and <i>Metaphire guillelmi</i> (105 individuals) at the end of the experiment.

The physical indices (Mean ± se) of two earthworm species including Eisenia fetida (105 individuals) and Metaphire guillelmi (105 individuals) at the end of the experiment.</p

Principle components analysis (PCA) of soil microbial and nematode communities under two earthworm species (<i>Eisenia fetida</i>, <i>Metaphire guillelmi</i>), and the different density of <i>Eisenia fetida</i> and <i>Metaphire guillelmi</i> treatments (Ba, bacterivores; Fu, fungivores; Pp, plant parasites; Om, omnivore-predators; Actinomy, actinomycetes; G+, gram-positive bacteria; G-, gram-negative bacteria; AMF, arbuscular mycorrhizal fungi).

+1E1, +2E1, and +4E1 represents added 1, 2, and 4 Eisenia fetida earthworm individuals, respectively; +1E2, +2E2, and +4E2 represents added 1, 2, and 4 Metaphire guillelmi earthworm individuals, respectively.</p

The abundance of total soil nematode, bacterivores, fungivores, plant-parasites, and omnivore-predators under two earthworm species (<i>Eisenia fetida</i>, <i>Metaphire guillelmi</i>), and the different density of <i>Eisenia fetida</i> and <i>Metaphire guillelmi</i> treatments.

The abundance of total soil nematode, bacterivores, fungivores, plant-parasites, and omnivore-predators under two earthworm species (Eisenia fetida, Metaphire guillelmi), and the different density of Eisenia fetida and Metaphire guillelmi treatments.</p

The abundance of total soil nematode, bacterivores, fungivores, plant-parasites, and omnivore-predators under two earthworm species (<i>Eisenia fetida</i>, <i>Metaphire guillelmi</i>), and the different density of <i>Eisenia fetida</i> and <i>Metaphire guillelmi</i> treatments.

The abundance of total soil nematode, bacterivores, fungivores, plant-parasites, and omnivore-predators under two earthworm species (Eisenia fetida, Metaphire guillelmi), and the different density of Eisenia fetida and Metaphire guillelmi treatments.</p

Fig 5 -

Redundancy analysis (RDA) showing the relationship between soil biota ((a) soil microbial community; (b) nematode community) and soil parameters. NH4+N, ammonium nitrogen; NO3-N, nitrate nitrogen; TP, total phosphorus; TN, total nitrogen; SOC, organic carbon; Availabl, available phosphorus. Actinomy, actinomycetes; G+, gram-positive bacteria; G-, gram-negative bacteria; AMF, arbuscular mycorrhizal fungi. Ba, bacterivores; Fu, fungivores; Pp, plant parasites; Om, omnivore-predators.</p