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In a small-scale field experiment, we estimated the contribution of aboveground litter to the energy budget of different collembolan and earthworm species. In a 50-year-old spruce plantation, the natural spruce litter was replaced by an equivalent amount of maize litter. The natural difference in the isotopic composition of carbon (C) between the spruce and maize allowed us to estimate the proportions of different carbon sources in the tissues of soil animals. The dependence on litter-derived C was least pronounced in Collembola having low δ15N values, indicating the feeding on non-vascular plants. In contrast, collembolans having high δ15N values belonged to the food chains based on fresh plant residuals. These results suggest that different species of litter-dwelling collembolans may regulate substantially different energy channels. Some species of endogeic earthworms (Aporrectodea rosea and A. caliginosa) utilize aboveground plant residues, though soil organic matter and other belowground sources of carbon prevail in the energy budget of their populations.

Earthworm species composition, the density of individuals, and their biomass were investigated in spring barley and faba bean fields in a long-term (52-year) experiment conducted at the Production and Experimental Station in Bałcyny, in north-eastern Poland (53°40′ N; 19°50′ E). Additionally, post-harvest residues biomass, soil organic matter (SOM), and soil pH were recorded. The above traits were investigated using two experimental factors: I. cropping system—continuous cropping (CC) vs. crop rotation (CR) and II. pesticide plant protection: herbicide + fungicide (HF+) vs. no plant protection (HF−). A total of three species of Lumbricidae were found: Aporrectodea caliginosa (Sav.) in both crops, Aporrectodea rosea (Sav.) in spring barley, and Lumbricus terrestris (L.) in faba bean. The density and biomass of earthworms were unaffected by experimental treatments in spring barley fields, whereas in faba bean CC increased and HF+ decreased earthworm density and biomass in comparison with CR and HF− respectively. Total post-harvest residues in faba bean fields were higher under CC in relation to CR and under HF+ compared with HF− treatment in both crops. Compared to CR, CC increased soil pH in spring barley fields and decreased in faba bean fields. Experimental factors did not affect SOM. Earthworm density and biomass were positively correlated with SOM content.

By means of a literature survey, earthworm species of significant relevance for soil functions in different biogeographical regions of Europe (Atlantic, Boreal, Mediterranean) were identified. These focal earthworm species, defined here according to the EFSA Guidance Document on the environmental risk assessment (ERA) of genetically modified plants, are typical for arable soils under crop rotations with maize and/or potatoes within the three regions represented by Ireland, Sweden and Spain, respectively. Focal earthworm species were selected following a matrix of four steps: Identification of functional groups, categorization of non-target species, ranking species on ecological criteria, and final selection of focal species. They are recommended as appropriate non-target organisms to assess environmental risks of genetically modified (GM) crops; in this case maize and potatoes. In total, 44 literature sources on earthworms in arable cropping systems including maize or potato from Ireland, Sweden and Spain were collected, which present information on species diversity, individual density and specific relevance for soil functions. By means of condensed literature data, those species were identified which (i) play an important functional role in respective soil systems, (ii) are well adapted to the biogeographical regions, (iii) are expected to occur in high abundances under cultivation of maize or potato and (iv) fulfill the requirements for an ERA test system based on life-history traits. First, primary and secondary decomposers were identified as functional groups being exposed to the GM crops. In a second step, anecic and endogeic species were categorized as potential species. In step three, eight anecic and endogeic earthworm species belonging to the family Lumbricidae were ranked as relevant species: Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea longa, Allolobophora chlorotica, Lumbricus terrestris, Lumbricus friendi, Octodrilus complanatus and Octolasion cyaneum. Five out of these eight species are relevant for each biogeographical region with an overlap in the species. Finally, the earthworm species Ap. caliginosa (endogeic, secondary decomposer) and L. terrestris (anecic, primary decomposer) were selected as focal species. In the Mediterranean region L. terrestris may be substituted by the more relevant anecic species L. friendi. The selected focal species are recommended to be included in a standardized laboratory ERA test system based on life-history traits. © 2016 Elsevier B.V.

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.

In recent years, the increasing number of biogas plants in operation has also led to a considerable rise in fermentative substrates, which are now widely used as agricultural fertilizers. The impact on earthworm fauna of using biogas digestate as a fertilizer has yet to be sufficiently researched. At two different tests sites, the short-term (four months after fertilization) and longer-term (three-year test period) influence of using fermented residues as a fertilizer was examined on earthworm density, biomass and community composition compared to using traditional fertilizers (cattle and pig slurry, chemical fertilizers as well as an unfertilized control). The crop grown was maize (Zea mays L.). Applying biogas digestate and slurry had a positive overall impact at both sites on earthworm density and biomass. Observing different fertilization regimes in the short term, the significantly highest earthworm density was seen where slurry had been applied. In the treatments with digestate and conventional slurry, earthworm biomass differed significantly in comparison with chemical fertilization and the untreated variant. After three years, earthworm biomass in the variants fertilized with conventional slurry and digestate tended to be higher than in the chemical fertilizer and untreated variants. Community composition was strongly influenced by the application of digestate. A decrease in the species Aporrectodea rosea was accompanied by an increase in Aporrectodea caliginosa. The earthworm population was supported equally positively at both sites by the variants with conventional slurry and digestate.

Within the regulatory framework for authorisation of plant protection products (PPPs) (EU Directive 91/414/1991/EEC replaced by Regulation (EC) 1107/2009), higher tier risk assessments and earthworm field tests are conducted in different countries across Europe. This paper describes dominant earthworm species for regulatory and biogeographical regions in agricultural landscapes across Europe and examines regional differences in earthworm communities and densities and their respective response to a toxic reference. For the assessment of earthworm abundance and species distribution, data of untreated control plots from 30 earthworm field studies were analysed; each conducted according to the ISO 11268–3 (1999) guideline by European Crop Protection Association member companies in the context of registration of PPPs. For the evaluation of the response to PPPs under different regional and climatic conditions, the effect on earthworm abundance was assessed by comparing plots treated with toxic references with untreated control plots. Additionally, a comparative literature review was included providing an overview of earthworm species composition and densities in agricultural crops from 14 European countries. The assessment of earthworm field studies from six different European countries revealed that common earthworm species of anecic and endogeic ecological groups are present at most field sites. Dominant species groups of endogeic and anecic earthworms can be defined that are abundant in all assessed countries. These are the endogeic species Aporrectodea caliginosa, Aporrectodea rosea and Allolobophora chlorotica, and the anecic species Lumbricus terrestris (Northern and Central Europe) and Lumbricus friendi (Southern Europe). Taking into account the high variability in total earthworm abundances, it can be concluded that the variability within regions was larger than the variability between regions. Analysis of the earthworm community and data of toxic references lead to the conclusion that testing in different zones is not considered necessary.

The most important indicators of biological activity (respiration, methane genesis, nitrogen fixation, denitrification, and size and structure of the microbial population) were determined in coprolites of two types of earthworms (Lumbricus rubellus considered as the “litter” type and Aporrectodea rosea as the “soil” type) in the model experiment, in which the earthworms were kept separately and together, as in soddy-podzolic loamy soil. The biological activity of coprolites was significantly higher than in the soil and varied between worm species.

The development of earthworms was investigated from 2001 to 2008 on the 176 ha arable fields of Ritzerau Farm (northern Germany) converted 2001–2004 from conventional to organic farming. Earthworms were recorded six times per year on a grid of 85 sampling points, whereas pH was determined in 2001 and 2005 and carbon content in 2001. Weak correlations between earthworm numbers and soil pH or organic matter of soil were found for few species, except for Lumbricus castaneus which was more abundant at pH > 6.5. Lumbricus rubellus benefited most from grain cultivation, Lumbricus terrestris from organic management. Aporrectodea caliginosa and Aporrectodea rosea were mainly related to rainfall and more abundant under 700–900 mm rain per year. Compensation of declined abundance after a period of heavy dryness lasted 0.5–1 year. The enhancement after conversion lasted 2–4 years and numbers increased from 0.2 to a maximum of 4.5 ind / m2.

Summary The soil seed bank functions to escape unfavourable environmental conditions and seed predation. Anecic earthworms are increasingly recognised as important dispersers and predators of plant seeds. In contrast, the role of the usually more abundant endogeic earthworms which live and feed in the soil on plant seeds is largely unknown. We tested whether (A) endogeic earthworms ( Aporrectodea rosea , Allolobophora chlorotica , Octolasion tyrtaeum , Aporrectodea caliginosa ) ingest and digest grassland plant seeds ( Phleum pratense , Bellis perennis , Trifolium repens , Poa trivialis , Plantago lanceolata , Medicago varia ), (B) the passage of seeds through the gut of endogeic earthworms modifies seed germination, and (C) excreta (mucus and casts) of endogeic earthworms modify seed germination. As a reference effects of the well-studied anecic species Lumbricus terrestris were determined. Endogeic earthworms ingested and digested all of the studied plant seeds; however, both ingestion and digestion were earthworm and plant species specific. Moreover, passage through the gut of endogeic earthworms and their excreta modified plant seed germination (gut passage: B. perennis ; excreta: Ph. pratense and Pl. lanceolata ). The results indicate that endogeic earthworms may strongly impact the composition of the soil seed bank and, consequently, plant community assembly via direct and indirect effects on plant seeds. Since post-dispersal seed predation is a key factor for the structure of plant communities, with the effect on seed survival potentially exceeding that of pre-dispersal predation, seed predation and changes in germination of seeds by endogeic earthworm species is likely to drive plant community composition.

Earthworm (Lumbricidae) populations were assessed in three replicated, field experiments with different management intensities conducted on grassland research farms on medium-textured mineral soils, located at Solohead (Co. Tipperary), Grange (Co. Meath) and Johnstown Castle (Co. Wexford), Ireland. The experiment at Solohead involved four levels of mineral fertilizer application (80, 175, 225 and 350 kg N ha−1), and the plots were rotationally grazed by dairy cows. Three levels of mineral fertilizer application were compared at Johnstown Castle (0, 225 and 390 kg N ha−1) and two at Grange (100 and 225 kg N ha−1), and the plots at these sites were rotationally grazed by suckler cows and followers or dry cattle. Between 10 and 15 earthworm species were recorded per site, with Allolobophora chlorotica and Aporrectodea caliginosa being dominant. Other abundant species included Aporrectodea rosea, Aporrectodea longa, Lumbricus terrestris, Lumbricus friendi, Lumbricus festivus, Lumbricus rubellus and Satchellius mammalis. Mean earthworm population densities per treatment ranged from 203 to 324 individuals m−2 and biomass from 60 to 176 g m−2. ANCOVA revealed significant overall positive relationships between management intensity (as indicated by N application rate) and earthworm abundance (F = 4.47, p

Two endogeic earthworms, Aporrectodea rosea and A. trapezoides (Lumbricidae), occur in soils used for grain production in southern Australia. A glass-house experiment evaluated the influence of A. rosea and A. trapezoides on the release and availability of nitrogen (N) in a red–brown earth soil, which is very common in the region. This soil had been treated with sub-terranean clover or wheat residues (both either added to the soil surface or mixed through the soil at the start of the experiment), wheat residues incorporated into the soil 5 years earlier, or no residue amendment (control). The survival and biomass of earthworms varied with amendment. Most notably, the biomass of individual A. trapezoides was greater in the presence of sub-clover (probably better quality food) and when in mixed culture with A. rosea (effectively a reduction in the density of A. trapezoides ). A. trapezoides increased soil inorganic N in the presence of surface-applied sub-clover residues, but A. rosea did not. Incorporation of sub-clover residues further increased soil N in the presence of A. trapezoides , but not A. rosea . Wheat residues immobilised N when incorporated, but A. trapezoides reduced this immobilisation. A. rosea did not. No earthworm effects were detected in the control and old wheat residue treatments. The work suggests that A. trapezoides has the potential to significantly increase the availability of N in a soil commonly used for grain production across southern Australia.

Earthworms Allolobophora chlorotica and Aporrectodea longa were inoculated into Calvert landfill site in spring 1992, in conjunction with the planting of two tree species Alnus glutinosa and Acer pseudoplatanus. Monitoring has taken place over a period of 11 years. Sampling in 2003 revealed that earthworm distribution no longer equated to the inoculation treatments; the worms had spread extensively. The presence of A. glutinosa had a significant effect (p

A mixed stand of red oak (Quercus rubra) and common beech (Fagus sylvatica) on a compacted and acidified sandy loam soil was harvested and reforested with ash (Fraxinus excelsior in 1992. The ecosystem restoration trial in this newly established ash plantation included 180 trees and was set up in a block design with 4 blocks, 3 experimental groups per block and 15 trees per experimental group. Experimental groups were: (1) application of P, K, Ca and Mg fertiliser to the planting pit; (2) combined application of fertiliser and earthworms to the planting pit; and (3) a control without additional restoration measures. Fertiliser application consisted of 500 g dolomite, 100g Thomas slags and 100g kieserite; earthworm introduction consisted of 40 individuals, being 20 anecics (Lumbricus terrestris L. and Nicodrilus longus Ude) and 20 endogeics (Aporrectodea caliginosa Sav., Aporrectodea rosea Sav. and Allolobophora limicola Michaelsen). Tree growth was monitored annually. The control trees failed to grow and died after two years. Excellent growth was found for treated trees, and treatment-related growth patterns were observed: fertilised trees grew faster than fertilised trees with earthworms during the first two years, with the trend reversed from year 4 onwards. Although this trend suggested that introduced earthworms provided a more sustained response to fertiliser, this was not conclusively confirmed by an evaluation of 24 trees 10 years after planting (based on nutrient concentration in above-ground biomass and soil, litter biomass, earthworm biomass, and aggregate stability of organic particles in the soil); although statistically significant differences were found between treated and untreated plots, differences between fertilised plots with and without earthworms were not significant. Endogeic earthworms recolonised most fertilised plots, with or without earthworm introduction. Anecic earthworms did not colonize any plots. Although our findings suggest that earthworm introduction might contribute to a sustained fertiliser response in ash trees, more experiments are needed to demonstrate the precise role of earthworm introduction as part of integrated forest soil restoration.

The earthworms, Aporrectodea rosea and A. trapezoides (Lumbricidae), occur commonly in soils used for grain production in south-eastern Australia, but their distributions are patchy and their abundance low. In a field experiment, inoculations of A. trapezoides, but not A. rosea, increased the growth of oats at early tillering and oat straw and grain yield at harvest. Neither earthworm species influenced the growth and yield of lupins. At early tillering of the oats and concurrent flowering of the lupins, the amounts of 1 5 N (from fertiliser applied the year before) taken up by both oats and lupins were greater in the presence of A. trapezoides, but not A. rosea. However, there were no differences in the % N in lupin and oat plants between the earthworm treatments. At harvest, there were no differences in the amounts of 1 5 N taken up by the lupin straw, nor were there in the % N in straw or grain for either lupins or oats between earthworm treatments. The 1 5 N contents of the oat straw and the lupin and oat grain were higher in the presence of both earthworm species when compared with controls. More than 90 % of the N in the lupins was fixed symbiotically. The proportion of fixed N was reduced slightly by A. trapezoides. Inorganic N was analysed at various depths in the soil profile at sowing and early tillering and flowering. An earthworm effect on soil inorganic N was recorded in only one instance - at early tillering / flowering, when soil inorganic N was slightly higher at 0.6-1 m depth in the presence of A. trapezoides. Management practices, which improve earthworm abundance, in particular that of A. trapezoides, in cropping soils in southern Australia may enhance productivity of some, but not all, crops.

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.

Studies of earthworm species and their activity, expressed as channels, on cultivated loamy (Humic Cryaquept) and clayey soils (Typic Endoaqualf and Typic Cryaquept) were conducted in southern and central Norway before conversion from conventional to organic cropping systems. At all the three study areas: Landvik (Grimstad), Voll (As) and Kvithamar (Stjordal), the earthworm species Aporrectodea caliginosa, Aporrectodea rosea, Allolobophora chlorotica and Lumbricus rubellus were found. At Landvik, where the deep-burrowing species Aporrectodea longa, A. caliginosa and Lumbricus terrestris dominated, medium (4–6 mm) and coarse (>6 mm) earthworm channels were most numerous below the plough layer. Almost no coarse pores were found at Voll and Kvithamar. The volume of earthworm channels below the plough layer was 0.6–0.8% of total soil volume at Landvik and Voll and 0.3–0.4% at Kvithamar. Earthworm channels >6 mm below the plough layer were useful to identify present and previous activity of deep-burrowing earthworms such as L. terrestris. Below the plough layer, roots were almost entirely restricted to earthworm channels and interaggregate spaces.

In a greenhouse study, the ability of two earthworm species (Aporrectodea trapezoides and Aporrectodea rosea) to alter the rate of growth of wheat, barley and faba beans in three soils of contrasting texture (sandy loam, loam and clay) was examined. Three experiments are reported. In experiment 1, A. trapezoides (1, 3 or 6 per pot of 1 kg soil) in the sandy loan was associated with a significant increase in the growth (31%) of wheat seedlings at 7 weeks old, but had no significant effect in the loam or clay soils. The presence of earthworms was associated with increased foliar N concentrations (10–20%) and water-use efficiency (4–17%) in all three soil types. In experiment 2, there were no significant effects of A. trapezoides or A. rosea (10 per pot of 4 kg soil) on the dry weight of faba beans at 10 weeks old, except for A. rosea in the loam soil which reduced the total dry weight by 17%. In experiment 3, both A. trapezoides and a. rosea (10 per pot of 4 kg soil) caused a significant increase in the dry weight of barley plants (60%), root growth (40% and 30%, respectively) the number of tillers (50% and 35%, respectively) and grain yields (50% and 45%, respectively) in the sandy loam soil but had no effect on these measures in the loam soil. In the clay soil the presence of both earthworm species was associated with a substantially reduced plant dry weight (40% and 20%, respectively), tiller number (20%) and grain yield (40% and 20%, respectively). A further treatment (NPK fertiliser applied at a rate commonly used in the field) produced no increase in growth of faba beans or wheat. Effects on soil hardness and bulk density varied with soil type and earthworm species. We conclude that the response of plants to earthworm activity varied with soil type and plant species.

The influence of the earthworms Aporrectodea trapezoides and A. rosea on subterranean clover and perennial ryegrass, grown in a red-brown earth soil artificially infested with R. solani , was examined. In soil artifically infested with R. solani on wheat chaff, the presence of A. trapezoides (at a number equivalent to 300 m −2 ) was associated with a significant reduction in the percentage length of roots containing Rhizoctonia lesions and a significant increase in shoot weight, root weight and root length of both subterranean clover and perennial ryegrass. The presence of A. rosea , at a number equivalent to 300 m −2 , was associated with a significant increase in the shoot weight and root length of subterranean clover, but A.rosea did not significantly influence the percentage root length containing Rhizoctonia lesions on either subterranean clover or perennial ryegrass. In the absence of R. solani inoculum, neither A. trapezoides or A. rosea influenced shoot weight, root weight or root length of subterranean clover. However, both earthworms significantly increased the shoot weight of perennial ryegrass in the absence of R. solani inoculum. These results demonstrate the potential of A. trapezoides and A. rosea to reduce the deleterious effect of R. solani on specific pasture plants.

Field surveys have shown that the introduced lumbricid earthworm, Aporrectodea rosea, predominates in fields used for cereal-pasture rotations in South Australia and western Victoria. Another introduced lumbricid, A. trapezoides, also occurs in these fields, but is usually much rarer. A glasshouse experiment investigated the influences of A. rosea and A. trapezoides on wheat and subterranean clover production. The plants were grown in a red-brown earth (Palexeralf), maintained at 60% field moisture capacity with the equivalent of 460 worms m−2. Wheat was grown first and then the soil was re-used for the clover. A. trapezoides increased wheat plant biomass by 39%, grain yield by 35%, grain N content by 14% and straw N content by 19% compared with controls (no worms). A. rosea increased wheat plant biomass by 13%, but had no significant influence on grain yield or grain or straw N content. The biomass of clover herbage was increased by 21% by A. trapezoides, but A. rosea had no effect. Neither earthworm species influenced the N content of the clover or the dry weight of clover roots. The implications of these results for future management of earthworms in cereal-pasture ratations are discussed.

Crop-monitoring by farmer groups has been established to identify agronomic and soil factors limiting crop yields and to promote the adoption of sustainable farming practices in South Australia. The use of earthworms as a potential indicator of sustainability has been investigated with a survey of 95 paddocks sown to wheat, barley or peas, within an area of about 3500 km 2 . Mean annual rainfall ranged from less than 350 mm to more than 500 mm, and soils varied from coarse sands through lighter loams to heavy clays. The dryland cropping soils in South Australia have been colonized by four immigrant earthworm species, Aporrectodea rosea (Savigny), Aporrectodea trapezoides (Duges), Microscolex dubius (Fletcher) and Microscolex phosphoreus (Duges); populations are generally dominated by A. rosea . Population differences, such as the higher numbers of A. rosea recorded under barley than peas and more juveniles under peas than wheat, and the occasional abundance of other species in some paddocks may be used to indicate changes in soil conditions associated with management. Conservation tillage, retaining plant-residues and reducing cultivation, is being promoted as desirable in developing sustainable farming systems and the inverse relationship between earthworm abundance and intensity of tillage (r = −0.69 ∗∗∗ ) provides support for earthworms as a potential indicator of sustainability. Earthworm abundance showed a small but significant correlation between earthworm activity and grain yields (r = 0.44 ∗∗∗ ) and grain protein content (r = 0.52 ∗∗∗ ). A positive correlation between nitrogen fertilizer levels and earthworm numbers (r = 0.48 ∗∗∗ ) and biomass (r = 0.43 ∗∗∗ ) may be related to increased soil organic matter, derived from increased plant growth. The distribution and abundance of earthworms is dependent not only on management related to crop production, but also on local soil and climatic factors. Density and biomass were significantly higher in paddocks with higher annual rainfall and inversely correlated with levels of coarse sand. The soils, crops, climate, management and history of a region of the geographic scale surveyed here is probably too diverse to provide simple relationships between earthworms and plant productivity. It is important to distinguish the broad concept of sustainable productivity on a regional basis from the reality of productivity and sustainability on the spatial and temporal scales of activity of the organisms studied and the production and management processes involved. At an appropriate scale, ecological data on both the species composition and on functional groups within earthworm communities, may be useful indicators of crop production and its sustainability.

In a field trial in a red-brown earth, the interaction between the earthworms Aporrectodea trapezoides and A. rosea (added at an equivalent density of 100 or 300 m −2 ) and wheat grain yield was examined, both in the presence or absence of inoculum of Rhizoctonia solani or the take-all fungus Gaeumannomyces graminis var. tritici (Ggt) . In the absence of R. solani or Ggt inoculum, neither earthworm significantly influenced plant top weight 71 days after sowing. However at harvest, A. trapezoides at an equivalent density of 100 or 300 m −2 significantly increased grain yield (by 56% and 82%, respectively) and plant top weight (by 53% and 76%, respectively). A. rosea at these densities did not significantly influence plant top weight or grain yield. In soil artificially infested with Rhizoctonia solani , there was a significant increase from 0.06 to 1.05 in the Rhizoctonia root disease rating 71 days after sowing, but R. solani inoculum did not significantly influence plant top weight or grain yield at harvest. A. trapezoides and A. rosea did not significantly influence the Rhizoctonia root disease rating and A. trapezoides (at an equivalent density of 300 m −2 ) was associated with a significant increase in grain yield at harvest. In soil artificially infested with Ggt , there was a significant increase from 0.2 to 94% in the length of seminal roots containing take-all lesions 71 days after sowing and plant top weight and grain yield were significantly reduced by Ggt inoculum at harvest. When the effects of the different densities of each earthworm species across all the Ggt treatments were averaged, both A. trapezoides and A. rosea (at an equivalent density of 100 or 300 m −2 ) significantly reduced the Ggt root disease rating. In the presence of Ggt inoculum, A. trapezoides and A. rosea (at an equivalent density of 300 m −2 ) were associated with a significant increase in plant top weight at harvest, but neither earthworm significantly influenced final grain yield. These results demonstrate the potential of A. trapezoides to increase wheat grain yield in the field and that this ability may be influenced by the presence of R. solani and Ggt .

The effects of previous cropping history (varying periods of pasture or arable management) on soil organic C and microbial biomass C content and on the size and composition of earthworm populations were investigated on a range of mixed cropping (arable in rotation with pasture) farms. Some 105 fields located at 24 different commercial farms across the Canterbury Plains of New Zealand were sampled during spring. No native megascolecid earthworms were recorded. Up to five introduced European species were identified at sample sites. Overall, about 80% of earthworms were Aporrectodea caliginosa ,10% were Aporrectodea trapezoides and 5% were Lumbricus rubellus . The remaining 5% were Octolasion cyaneum and Aporrectodea rosea . All five species were found under long-term pasture. As the length of time under arable production increased, the number of species declined until, under continuous arable production, only A. caliginosa and A. trapezoides were recovered. Although soil organic C content was not greatly affected by cropping history, microbial biomass C content generally increased with time under pasture and decreased with time under arable. Earthworm numbers and biomass showed a similar but more pronounced trend to that of microbial biomass. This trend is reflected in the increased organic matter inputs under pasture and decreased inputs and increased decomposition under arable. In mixed cropping rotations, earthworm populations varied greatly with cropping history. Populations reached their maximum (over 800 m −2 ) after about 3 years under pasture whilst with more than 3 years under arable they were less than 400 m −2 . With continuous arable production for more than 9 years, populations fell to below 100 m −2 . Similar trends were found for earthworm biomass.

An understanding of the effects of ploughing on earthworm dynamics is required for the design of organic cropping systems maximising the beneficial effects of earthworms. Earthworms are often reported to be disturbed by ploughing, which is frequently used for weed control in organic farming. In this preliminary study, we investigated the effect of ploughing on the dynamics of two common endogeic species: Aporrectodea caliginosa and Aporrectodea rosea, to test the assumption that the sensivity to ploughing is species dependant. Two field trials were set up in October 2009 and November 2010, at two locations on a haplic luvisol, located in northern France. For comparison, part of each field was left unploughed, with the rest being ploughed. Earthworms were sampled at ten dates between October 2009 and July 2010 at Vi and six dates between November 2010 and March 2011 at Fa. Seven species were found in these two fields, with more than 88% of the earthworms belonging to two endogeic species, A. caliginosa and A. rosea. Ploughing had contrasting effects on the two species. A. caliginosa was more sensitive than A. rosea to tillage. In the unploughed part of the field, in 2009, the population remained small (less than 100 individuals m(-2)) and it was assumed that the two species were in competition for food. In 2010, the carrying capacity was higher, and A. caliginosa abundance reached 300 individuals m(-2), whereas the abundance of A. rosea remained below 90 individuals m(-2). In 2009, the effect of ploughing on A. caliginosa was immediate and persisted throughout the experiment, from October 2009 to June 2010, with an 80% decrease in abundance in June 2010. In 2010, the effect was delayed, but populations decreased during the winter following ploughing, with a 60% decrease in January 2011. Concerning A. rosea, the differences between the ploughed and the unploughed treatments were lower than for A. caliginosa. Our results confirm that endogeics earthworms may adapt themselves to the disturbance caused by tillage. Our observations suggest that A. caliginosa is more sensitive to ploughing than previously reported. These preliminary findings were obtained under favourable climatic conditions. They may help to define the optimal scheduling of tillage for earthworm conservation. (C) 2012 Elsevier B.V. All rights reserved.

A study demonstrated the ability of the earthworms Aporrectodea rosea and Aporrectodea trapezoides (added at an equivalent density of 100 or 300 m −2 ) to reduce the disease severity of Rhizoctonia soiani Kuhn on wheat in the field. In a calcareous sandy loam artificially infested with R. solani , the addition of these earthworms caused a significant ( P = 0.02) reduction of the Rhizoctonia root disease rating and had a significant ( P = 0.01) positive effect on shoot weight. Neither earthworm number or earthworm species had a significant ( P R. solani , neither the presence of these earthworms, earthworm species nor earthworm number influenced root disease rating. However, under these conditions the addition of earthworms ( P = 0.01) had a significant positive effect upon shoot weight. To our knowledge these results demonstrate for the first time, the potential of earthworms to contribute to the disease suppression of a cropping soil in a field situation.

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-2, 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-2, 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.

The capacity of earthworms and soil microorganisms to influence plant growth is well known. However, the interactions between them have been little studied. Recent work in southern Australia has examined these associations with a view to managing both earthworms and beneficial microorganisms to promote cereal and pasture productivity. In this paper we examine the role of earthworms as vectors of beneficial soil bacteria and their capacity to influence the population dynamics and impact of microorganisms on soil and plants. The earthworms Aporrectodea trapezoides and Aporrectodea rosea are the most common species in agricultural ecosystems in southern Australia. They have been shown to spread Pseudomonas corrugata 2140R, a biocontrol agent for Take-all (a fungal disease of wheat roots caused by Gaeumannomyces graminis var. tritici ) through soil with corresponding colonization of the roots of wheat seedlings at soil depths of 3–9 cm. In addition, A. trapezoides can spread Rhizobium through the soil and cause increased root colonization and nodulation of legume roots. Despite evidence that populations of soil microorganisms are affected by earthworm activity at a small spatial scale (e.g. in casts or tunnel walls), there is little evidence to demonstrate that earthworms affect populations at larger spatial scales. Take-all and Rhizoctonia bare patch are the most serious fungal root diseases of wheat in southern Australia. Laboratory trials have shown that, in the presence of the worms A. trapezoides and A. rosea , symptoms of these diseases in wheat seedlings are substantially reduced. In a further trial, the presence of A. trapezoides was associated with a 100-fold decrease in population size of Rhizobium recoverable from soil after 40 days.

The earthworm fauna of soils used for pasture-cereal rotations in south-eastern Australia was surveyed in 1990–91 (126 sites). Numbers were generally low (0–366 m-2, mean = 41.9 m-2 for all species combined). The fauna was dominated by introduced species. Aporrectodea rosea (Lumbricidae) was the most common species (mean = 31.4 m-2) followed by A. trapezoides (5.0 m-2). A. rosea and A. trapezoides were found at 45 and 29% of sites, respectively. There was no obvious relationship between earthworm abundance and soil pH.

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (

The abundances of the introduced earthworms, Aporrectodea rosea, A. trapezoides, Microscolex dubius and M. phosphoreus were monitored monthly in the top 30 cm of soil at three farms used for cereal and lucerne production in South Australia. The farms had approximately 500 mm annual rainfall. Total earthworm densities of up to 303 m-2 were recorded, with the Aporrectodea spp. far more abundant than the Microscolex spp. Highest numbers were found in winter and early spring, when the soils were wettest (water suction potential < approx. 150 kPa) and the majority of worms were present in the top 10 cm of soil. During the drier months of the year, most worms were found below 10 cm depth. Adults with mature clitella were restricted to winter and spring. Juveniles and adults (with regressed clitella) of Aporrectodea spp. survived summer.

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–CO2 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.