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Nowadays, when one of the most significant problems for mankind is saving the soil from pollution. It is well-known that one of the most important means of soil rehabilitation and remediation are soil inhabitants, their biodiversity and products of their life activity. Given the significant role of soil inhabitants in soil formation processes, it is important to consider their role in the processes of reprocessing and bioaccumulation of heavy metals. That especially concerns the earthworms, whose role in soil formation and maintenance of natural fertility is well-known and causes the interest of soil scientists and ecologists. The paper shows the degree of bioaccumulation of heavy metals (copper, zinc and lead) in the body of earthworms. Study involved three species of earthworms, which were collected in the vicinity of Tbilisi – Aporrectodea rosea (Savigny, 1826), Eisenia veneta (Rosa, 1886) and Allolobophora chlorotica (Savigny, 1826) – showed that earthworms of different species accumulate different amounts of heavy metals – copper, zinc and lead and, depending on the species, after being placed in heavy metals solutions, they demonstrate the different intensity of movement. The amount of heavy metals in the body of an earthworm depends on the structure of the body tissues and maybe on the structure of the skin-muscular sac.

Permanent grasslands provide a healthy and undisturbed environment. We investigated how mulching altered the soil physicochemical parameters, earthworm abundance, biomass, species composition and vegetation cover compared to grassland and cultivated alfalfa field. Microplots (2 × 2 m) were mulched with either weed control fabric (WF) alone or WF combined with straw (WF + S) on a grassland to grow tomato in Ősagárd (Nógrád county, Hungary) between 2018 and 2021. We had two other microhabitats: a conventionally cultivated alfalfa field (CA) and grassland (GR). We measured soil parameters (physical: soil moisture content (SMC), soil penetration resistance (SPR); chemical: pH, soil organic matter; and biological: earthworm abundance, biomass, species composition and vegetation). SMC was significantly higher on covered plots (WF; WF + S) compared to CA and GR. SPR values were the highest in CA and GR at 20 cm depth. The abundance and biomass of earthworms were the highest in GR and lowest in CA in all seasons. Plant abundance was highly influenced by season and habitat. Despite the higher compaction and lower SMC figures, grass vegetation still provided a more suitable environment for earthworms than mulched plots (WF, WF + S). Therefore, where there is agricultural production on grassland, we suggest leaving uncultivated and uncovered patches as biodiversity corridors. [ABSTRACT FROM AUTHOR]

Nowadays, when one of the most significant problems for mankind is saving the soil from pollution. It is well-known that one of the most important means of soil rehabilitation and remediation are soil inhabitants, their biodiversity and products of their life activity. Given the significant role of soil inhabitants in soil formation processes, it is important to consider their role in the processes of reprocessing and bioaccumulation of heavy metals. That especially concerns the earthworms, whose role in soil formation and maintenance of natural fertility is well-known and causes the interest of soil scientists and ecologists. The paper shows the degree of bioaccumulation of heavy metals (copper, zinc and lead) in the body of earthworms. Study involved three species of earthworms, which were collected in the vicinity of Tbilisi – Aporrectodea rosea (Savigny, 1826), Eisenia veneta (Rosa, 1886) and Allolobophora chlorotica (Savigny, 1826) – showed that earthworms of different species accumulate different amounts of heavy metals – copper, zinc and lead and, depending on the species, after being placed in heavy metals solutions, they demonstrate the different intensity of movement. The amount of heavy metals in the body of an earthworm depends on the structure of the body tissues and maybe on the structure of the skinmuscular sac. [ABSTRACT FROM AUTHOR]

Permanent grasslands provide a healthy and undisturbed environment. We investigated how mulching altered the soil physicochemical parameters, earthworm abundance, biomass, species composition and vegetation cover compared to grassland and cultivated alfalfa field. Microplots (2 × 2 m) were mulched with either weed control fabric (WF) alone or WF combined with straw (WF + S) on a grassland to grow tomato in Ősagárd (Nógrád county, Hungary) between 2018 and 2021. We had two other microhabitats: a conventionally cultivated alfalfa field (CA) and grassland (GR). We measured soil parameters (physical: soil moisture content (SMC), soil penetration resistance (SPR); chemical: pH, soil organic matter; and biological: earthworm abundance, biomass, species composition and vegetation). SMC was significantly higher on covered plots (WF; WF + S) compared to CA and GR. SPR values were the highest in CA and GR at 20 cm depth. The abundance and biomass of earthworms were the highest in GR and lowest in CA in all seasons. Plant abundance was highly influenced by season and habitat. Despite the higher compaction and lower SMC figures, grass vegetation still provided a more suitable environment for earthworms than mulched plots (WF, WF + S). Therefore, where there is agricultural production on grassland, we suggest leaving uncultivated and uncovered patches as biodiversity corridors.

Soil invertebrates are crucial for agroecosystem functioning yet sensitive to agricultural practices, including fertilization. Considering the postulates of circular phosphorus economy, the use of fertilizers from secondary raw materials is likely to return and increase and may even become obligatory. The effects of recycled fertilizers on soil fauna communities, however, remain poorly understood. In this paper, the effect of phosphorus fertilizer (RecF) and biofertilizer (RecB) from sewage sludge ash and dried animal (porcine) blood on earthworm’s occurrence in soil is discussed. RecB is RecF activated by phosphorus-solubilizing bacteria, Bacillus megaterium. Waste-based fertilizers were assessed in field experiments against commercial superphosphate and no P fertilization. Three levels of P doses were established (17.6, 26.4, and 35.2 kg P ha−1). Earthworms were collected after the test crop harvest (spring or winter wheat). In the experiments two earthworm species, Aporrectodea caliginosa and Aporrectodea rosea, were identified. A large proportion of juvenile individuals were recorded in 2017. The recycled fertilizers used in the experiments used in recommended doses, similarly to superphosphate, did not alter the density, biomass, species composition, and structure of earthworms. Further long-term field research is recommended.

The article presents the data on prevalence and intensity of earthworms' infection with metastrongylid larvae in pork production enterprises of Kyiv and Zhytomyr Regions of Ukraine. In the investigated areas, six species of lumbricids were collected and identified: Eisenia fetida (Savigny, 1826), Aporrectodea rosea (Savigny, 1826), A. caliginosa (Savigny, 1826), Dendrodrilus rubidus (Savigny, 1826), Lumbricus rubellus (Linnaeus, 1758), L. terrestris (Linnaeus, 1758). The studies were carried out from April to September, 2016, both in pig farms and on pastures. We observed no pronounced changes in prevalence and intensity of infection during the warm period of the year. The highest infection rates were detected in earthworms living under the wooden floor of pigpens and in its cracks. In the studied localities, metastrongylid larvae were found in the most common worms of the Lumbricidae family: E. foetida, D. rubidus, A. caliginosa, and L. rubellus. [ABSTRACT FROM AUTHOR]

The current study explores the influence of soil organic matter content on abundance and biomass of earthworm communities. The observation was carried out on three type of soils: Pellic Vertisols (very fine texture), Cromi-Vertic Luvisols (fine texture) and Calcaric Fluvisols (medium texture) from the Balkan Peninsula (Bulgaria). The field experiment was provided on uncultivated plots. In the studied area earthworm fauna comprises of four species: Aporrectodea rosea, Aporrectodea caliginosa, Lumbricus terrestris and Octolasion lacteum. We found peregrine lumbricid taxa, which are widely distributed in European soils. Our study demonstrated that soil organic matter has a positive effect on lumbricid populations. It was revealed that augmentation of soil organic matter favours characteristics of earthworm communities. The soil organic matter content and earthworm abundance are in strong positive correlation (r > 0.981). The same relationship was revealed between the biomass of lumbricid fauna and amount of soil organic matter (r > 0.987). In sum, the soil organic matter could be used as an indicator for earthworm communities in uncultivated soils. [ABSTRACT FROM AUTHOR]

Earthworms are considered as key actors of soil processes at different spatial and temporal scales and provide essential ecosystem services linked to climate regulation or primary production. However, little is known about their basic functional roles (e.g. organic matter decomposition, soil structuring processes) in perturbed systems such as urban or alluvial soils. Alluvial soils are characterized by regular physical perturbation through flooding and associated erosion/sedimentation processes which are rather similar to perturbations (e.g. temporal instability, spatial heterogeneity) affecting urban soils. Due to their close soil characteristics, we hypothesized that in both cases, soil functioning is similar with respect to soil fauna activity. Under controlled conditions, our objective was to investigate the effects of two endogeic earthworm species, Allolobophora chlorotica (pink morph) and Aporrectodea rosea (the two most abundant species found in the studied urban site), on soil organic matter (SOM) dynamics and soil structure (network of earthworm burrows) comparing an urban and an alluvial soil. We investigated the growth of individuals (weight gain and reproduction success) and assessed their effects on SOM decomposition (cumulative C–CO 2 emission, nitrogen and phosphorus mineralization) and soil structure (macroporosity, total length and connectivity of segments) after one and three months of incubation. Our results showed higher growth of A. rosea in the alluvial soil compared to the urban soil. However, the total length of burrows, carbon and nitrogen mineralization were often higher in the urban soil especially when the two species were combined. This trend can be mainly explained by lower organic matter content found in the urban soil which may influence positively the burrowing activity and negatively the growth of earthworms. Endogeic earthworms appear a key feature of the soil functioning in the urban context through their roles on organic matter transformation, the formation and maintenance of the soil structure. [ABSTRACT FROM AUTHOR]

Earthworms are recognized to increase soil porosity, reorganize soil structure, and stimulate soil microflora and nutrient mineralization. The properties of earthworm casts should depend both on earthworm species or ecological group and on soil properties. Interactions between earthworm species and soil types have been suggested, but only poorly demonstrated. In order to better understand those interactions, two hypotheses led our study: (1) Soil type has a greater influence on cast properties than earthworm; (2) Earthworms from different species influence cast properties differently; (3) The intensity and direction of the impact of each earthworm species on cast properties vary with soil properties. Fifteen physical and chemical variables (N–NH 4 + , N–NO 3 − , total organic C and N, C/N ratio, CaCO 3 , pH, P, K + , Mg 2+ , Mn 2+ , Na + , CEC, moisture, wettability) were measured in casts of three earthworm species ( Lumbricus terrestris , Allolobophora chlorotica and Aporrectodea rosea ) produced in three temperate soils. Univariate and multivariate analyses showed that earthworm species and soil types significantly impacted cast properties. pH, N t , K and Mg contents were interactively altered by both factors. Multivariate analysis showed that a difference of soil type had a major impact on casts properties (62%) compared to the impact of a difference of earthworm species (10%). Cast properties were most impacted by L . terrestris , then by A . chlorotica and last by A . rosea . The response ratio (ratio of the properties of the casts to the properties of the bulk soil) was used to quantify the effect of earthworm species compared to the control soil. It showed a higher response of variables in casts in nutrient-rich soils, especially in casts of L . terrestris . The interactions between earthworm species and soil types on cast properties were discussed with regards to earthworm ecology, properties of the soil, and earthworm modifications of cast microflora. [ABSTRACT FROM AUTHOR]

Four chromosomal races (2n=36, 3n=54, 6n=108, 8n=144) and 96 clones have been revealed among 224 specimens of the earthworm A. rosea over the territory of Ukraine by means of karyological analysis and biochemical genetic marking. Each population has been showed by several clones at least; moreover the clones from different places have never been identical. The clones in the range of one population can be identified with the set of quantitative and qualitative parameters. [ABSTRACT FROM AUTHOR]

Abstract: A clear understanding of the size and structure of earthworm communities is important to sports turf facilities managers if they are to control the activity of earthworms within the soil. Earthworms are directly linked to a wide range of biogeochemical nutrient cycles, and are frequently described as ecosystem engineers. In this role they assist land managers in maintaining a healthy turf sward. Despite this, earthworm populations in sports turf were frequently suppressed using organochloride based vermicides prior to such compounds being banned in the UK. A survey of earthworm species diversity was carried out over 1 year, using mustard extraction at five golf courses in Bedfordshire and Buckinghamshire, UK, to investigate how species diversity varied temporally and was influenced by the physical environment within different course surfaces. Rank–abundance analysis indicated that four species of earthworm (Aporrectodea rosea, Lumbricus rubellus, Aporrectodea longa and Lumbricus terrestris) were more dominant in the community than any other. The endemic earthworm population number of the five study sites was found to differ significantly (p <0.01) related to their geographical location, and the most diverse communities were found where the population was greatest. A very strong linear correlation was found between the number of earthworms recovered and the sand content of the soil (r 2 =0.97). Significant differences in the size of the earthworm populations were recorded at different times of the year (p <0.01). A distinct and non-linear relationship between species diversity and microbial biomass C was shown (p <0.01). [Copyright &y& Elsevier]

Abstract: Earthworms are known to be important regulators of soil structure and soil organic matter (SOM) dynamics, however, quantifying their influence on carbon (C) and nitrogen (N) stabilization in agroecosystems remains a pertinent task. We manipulated population densities of the earthworm Aporrectodea rosea in three maize-tomato cropping systems [conventional (i.e., mineral fertilizer), organic (i.e., composted manure and legume cover crop), and an intermediate low-input system (i.e., alternating years of legume cover crop and mineral fertilizer)] to examine their influence on C and N incorporation into soil aggregates. Two treatments, no-earthworm versus the addition of five A. rosea adults, were established in paired microcosms using electro-shocking. A 13C and 15N labeled cover crop was incorporated into the soil of the organic and low-input systems, while 15N mineral fertilizer was applied in the conventional system. Soil samples were collected during the growing season and wet-sieved to obtain three aggregate size classes: macroaggregates (>250μm), microaggregates (53–250μm) and silt and clay fraction (<53μm). Macroaggregates were further separated into coarse particulate organic matter (cPOM), microaggregates and the silt and clay fraction. Total C, 13C, total N and 15N were measured for all fractions and the bulk soil. Significant earthworm influences were restricted to the low-input and conventional systems on the final sampling date. In the low-input system, earthworms increased the incorporation of new C into microaggregates within macroaggregates by 35% (2.8gm−2 increase; P=0.03), compared to the no-earthworm treatment. Within this same cropping system, earthworms increased new N in the cPOM and the silt and clay fractions within macroaggregates, by 49% (0.21gm−2; P<0.01) and 38% (0.19gm−2; P=0.02), respectively. In the conventional system, earthworms appeared to decrease the incorporation of new N into free microaggregates and macroaggregates by 49% (1.38gm−2; P=0.04) and 41% (0.51gm−2; P=0.057), respectively. These results indicate that earthworms can play an important role in C and N dynamics and that agroecosystem management greatly influences the magnitude and direction of their effect. [Copyright &y& Elsevier]

The influence of drying and ageing on the stabilization of casts produced by the endoge´ic earthworm, Aporrectodea rosea, from a soil, which was hard-setting and low in organic matter, were investigated in the laboratory. Casts and uningested soil were aged-most for up to 32 days, dried for up to 21 days, or subjected to different wetting and drying cycles over 30 days. The dispersion index of aged-moist casts decreased from 0.40 to 0.25 over 32 days, while dispersion index of dried casts decreased from 0.40 to 0.01 over 21 days. The dispersion index of air-dried casts was not significantly increased by five cycles of wetting and drying. The dispersion index of dried casts was not significantly less than that of dried soil. In soils wetter than a matric potential of approximately –35kPa, stabilization of casts was probably due to a combination of cohesion of soil particles, age-hardening and growth of microorganisms. However, in soils drier than –35kPa, cementation was probably the major mechanism of stabilization. The addition of wheat straw to the soil prior to ingestion by earthworms increased dispersion from aged-moist casts, but did not influence dispersion from dried casts. The addition of wheat straw decreased the number of air-dried casts which slaked severely. The concentration of soluble carbohydrate decreased with dispersion index as casts and uningested soil were each dried. This suggested that soluble carbohydrate may have been denatured with or without being bonded to soil particles during drying. [ABSTRACT FROM AUTHOR]

The mechanisms by which soil is destabilized in the digestive tract of endogéic earthworms were investigated with artificial casts, which were moulded with a syringe from slurries of a silty loam with or without gypsum and organic matter treatments, and compared to casts produced by Aporrectodea rosea (Lumbricidae). Both types of casts generally had the same levels of mechanical dispersion, observations of slaking, and particle size distribution when the casts were fresh, aged-moist for 30 days, or air-dried. Fresh casts were significantly more dispersive than the uningested soil despite the addition of gypsum or organic matter to the soil. However, the dispersion from aged-moist or air-dried casts was not substantially greater than that of uningested soil. Air-drying was more effective than moist-ageing in increasing the stability of casts and uningested soil. The concentration of soluble carbohydrate was greater in artificial casts produced from soil treated with sheep dung or xanthan gum, and in earthworm casts produced from soil treated with xanthan, than in the uningested soil of the same treatments. An increase in the concentration of soluble carbohydrate was related to an increase in dispersion. An attempt was made to simulate the addition of mucus to soil in the digestive tract of earthworms, by the addition of sucrose or xanthan gum to the slurry during the production of artificial casts. The addition of xanthan, but not sucrose, to the slurry increased mechanical dispersion relative to that of the uningested soil in the fresh treatment. Although the production of artificial casts destabilized soil to the same degree as earthworm casts, the artificial casts did not simulate all chemical, biochemical, and microbiological aspects of digestion. [ABSTRACT FROM AUTHOR]

The question of whether the response of earthworms to soil moisture is governed by their reaction to soil wetness (moisture content) or to soil water energy (matric suction) was examined in two species of earthworm using moisture gradients in three contrasting soil types with clay contents varying from 4 to 39%. Gravimetric moisture gradients ranging over 5-30% were established in horizontal cores comprising 12 or 14 sections containing loosely packed soil. Earthworms were introduced to each section at the beginning of each experiment. The earthworms moved from sections containing dry soil into adjacent sections containing moister soil. Clear effects were evident after 6 h but these became more obvious after 96 h. For the earthworm Aporrectodea rosea, the threshold soil mositure level at which earthworms were induced to move away from dry soil was a matric suction of about 300 kPa (pF 3.4) and was independent of soil type. In contrast, for A. trapezoides, the threshold soil moisture varied with soil type (sandy loam 15 kPa, loam 25 kPa, clay 300 kPa). We conclude that, for the earthworm A. rosea, matric suction and not water content of soil provided the cue by which the earthworm recognized dry soil. For A. trapezoides, there was an interaction between matric suction and soil type in which the response of A. trapezoides to soil moisture varied with soil texture and the threshold for avoidance of dry soil ranged from a matric suction of 300 kPa (20% w/w) in clay to 15 kPa (10% w/w) in sandy loam. [ABSTRACT FROM AUTHOR]

In a greenhouse study, the ability of the earthworms Aporrectodea rosea and A. trapezoides to influence the foliar concentration of elements and the growth of wheat plants was assessed 27 days after sowing in a sandy loam soil. The presence of A. rosea and A. trapezoides (at densities equivalent to 314 and 471 m, respectively) caused a significant increase in the shoot dry weight of wheat. The presence of A. rosea and A. trapezoides (at densities equivalent to 314 and 157 m, respectively) was also associated with a significant increase in the root dry weight of wheat. The presence of A. rosea caused a significant increase in the foliar concentration of Ca, Cu, K, Mn, N, Na, and P, but did not influence the foliar concentration of Al, B, Fe, Mo, Mg, S, and Zn. The presence of A. trapezoides was associated with a significant increase in the foliar concentration of Al, Ca, Fe, K, Mn, N, and Na, but did not influence the foliar concentration of B, Cu, Mo, Mg, P, S, and Zn. These results demonstrate the potential of A. rosea and A. trapezoides to increase the growth of wheat in a sandy loam soil and suggest that the mechanism by which they increased plant growth was, in part, through increasing the availability and uptake of nutrients from this soil. [ABSTRACT FROM AUTHOR]

The axial forces generated by the earthworm Aporrectodea rosea were measured by directing the earthworm to tunnel into soil discs mounted on an electronic balance connected to a datalogger. The area over which the force acted was estimated from the size of the hole created by the tunnelling. The maximum force recorded by an individual worm was 0.760 N and the mean maximum value was 0.465 N. The maximum pressures recorded was 116.5 kPa, while the mean maximum pressure was 72.8 kPa. These axial pressures are approximately one-tenth of the maximum axial pressure recorded for plant roots. The statistical distribution of activity as the worms tunnelled through the soil discs was analysed. Pressures recorded were well in excess of physiologically measured pressures and the generation of forces within muscles to achieve these pressures was calculated by some assumptions. It was estimated that there is a maximum tension in the circular muscles of 0.15 N per segment of the worm. [ABSTRACT FROM AUTHOR]

The radial pressures generated by the earthworm Aporrectodea rosea were measured in a study of the conditions under which the worms were able to crack soil discs into which they were encouraged to tunnel. The tensile strength of replicate discs was determined by indirect tension tests and by expansion of rubber membranes in soil discs. Simple engineering theory was used to relate the stress required to fracture a disc with the applied internal stress. Mean values for the radial stress applied by the earthworms in tunnelling through the discs was 230 kPa. With some assumptions about the distribution of muscles across the worm diameter, it was estimated that the mean maximum force generated by all the longitudinal muscles in any segment was 3.2 N. [ABSTRACT FROM AUTHOR]

Some physical properties of casts of the earthworm Aporrectodea rosea were examined and compared with the properties of aggregates from the bulk soil. Cast shape was quantified by three ratio methods and two mathematical spectra methods, using data obtained by two-dimensional scanning. Shapes were compared with previously published descriptions of 'modexi'. The tensile strength of dry casts was measured by the indirect tension method and was found to be approximately 2.5 times greater than that of dried aggregates of similar size. Tensile strengths are used to predict that beds of casts are less compactable than beds of aggregates. From relationships between soil water content, matric potential and undrained shear strength of fresh earthworm casts, the mean pressure applied to soil as it is remoulded by passing through the earthworm gut is estimated to be 259 Pa. [ABSTRACT FROM AUTHOR]

Aporrectodea rosea (Savigny, 1826) is a cosmopolitan earthworm widespread throughout the Holarctic. The available data on A. rosea genetic diversity (mainly from the Mediterranean region) suggests that this species can be divided into the Mediterranean and the Eurosiberian lineages. In this study we tested molecular variation within this species from the Northeastern Palearctic, namely from Russia, Belarus, and Kazakhstan, using nuclear and mitochondrial sequences. We detected previously unknown genetic diversity within the Eurosiberian lineage: basal representatives of this group from the south of Belarus were only distantly related to the rest of the lineage. This suggests that after the split of A. rosea into the Mediterranean and the Eurosiberian lineages, the latter diversified in eastern Europe with subsequent recolonization of the Mediterranean region. The paleogeographic history of this species is thus more complex than it was thought earlier. We found that A. rosea significantly increased its range over the last two decades, now being found in West Siberia; genetic diversity there is low compared to European Russia and Belarus. Compared to the closely related A. caliginosa , A. rosea had lower genetic diversity, probably caused by fewer dispersal events. • We studied a sample of Aporrectodea rosea from the Northeastern Palearctic. • All A. rosea specimens belonged to the Eurosiberian lineage. • New basal clades of the Eurosiberian lineage was found. • Eurosiberian lineage diversified in Eastern Europe then recolonized the Mediterranean. • A. rosea significantly increased its range over the last decades. [ABSTRACT FROM AUTHOR]

Soil invertebrates are crucial for agroecosystem functioning yet sensitive to agricultural practices, including fertilization. Considering the postulates of circular phosphorus economy, the use of fertilizers from secondary raw materials is likely to return and increase and may even become obligatory. The effects of recycled fertilizers on soil fauna communities, however, remain poorly understood. In this paper, the effect of phosphorus fertilizer (RecF) and biofertilizer (RecB) from sewage sludge ash and dried animal (porcine) blood on earthworm's occurrence in soil is discussed. RecB is RecF activated by phosphorus-solubilizing bacteria, Bacillus megaterium. Waste-based fertilizers were assessed in field experiments against commercial superphosphate and no P fertilization. Three levels of P doses were established (17.6, 26.4, and 35.2 kg P ha−1). Earthworms were collected after the test crop harvest (spring or winter wheat). In the experiments two earthworm species, Aporrectodea caliginosa and Aporrectodea rosea, were identified. A large proportion of juvenile individuals were recorded in 2017. The recycled fertilizers used in the experiments used in recommended doses, similarly to superphosphate, did not alter the density, biomass, species composition, and structure of earthworms. Further long-term field research is recommended. [ABSTRACT FROM AUTHOR]