Earthworm Populations Research Articles

Studies on earthworm population densities in garbage area at urban environment Hyderabad, Telangana State, India

Studies on earthworm population densities in garbage area at urban environment Hyderabad, Telangana State, India

Acidification of previously limed upland pastures – An overlooked flood risk factor?

In low-lying land, the impact of agriculture on flooding has focussed on soil compaction, whilst in the uplands there has been more interest in the influence of afforestation. The potential effect of acidification of previously limed upland grassland soils on this risk has been overlooked. The marginal economics of upland farms has led to inadequate lime application on these grasslands. In Wales, UK, agronomic improvement of upland acid grasslands with liming was widespread in the last century. The extent and topographical distribution of this land use in Wales was estimated and these characteristics were mapped in four catchments studied in more detail. Then 41 sites on improved pastures within the catchments were sampled, where lime had not been applied for periods of between two and 30 years; unimproved acid pastures adjacent to five of these sites were also sampled. Soil pH, organic matter, infiltration rates and earthworm populations were recorded. Grasslands at risk of acidification without maintenance liming were estimated to cover almost 20 % of upland Wales. The majority of these grasslands were located on steeper slopes (gradients >7o) where any reduction in infiltration would promote surface runoff and limit rainwater retention. The extent of these pastures varied markedly between the four study catchments. There was a 6-fold reduction in infiltration rates between high and low pH soils, and this trend was correlated with reductions in anecic earthworm abundance. The vertical burrows of these earthworms are important for infiltration and no such earthworms were present in the most acidic soils. Recently limed soils had infiltration rates similar to those of unimproved acid pastures. Soil acidification has the potential to exacerbate flood risk but further research is needed to assess the extent of any impact. Modelling of catchment specific flood risk should include the extent of upland soil acidification as an additional land use factor.

Cover Crops Boost Earthworm Populations

CSA NewsVolume 68, Issue 4 p. 13-13 SOCIETY SCIENCE Cover Crops Boost Earthworm Populations First published: 24 March 2023 https://doi.org/10.1002/csan.20990Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume68, Issue4April 2023Pages 13-13 RelatedInformation

Natural farming improves crop yield in SE India when compared to conventional or organic systems by enhancing soil quality

Zero Budget Natural Farming (ZBNF) is a grassroot agrarian movement and a state backed extension in Andhra Pradesh, and has been claimed to potentially meet the twin goals of global food security and environmental conservation. However, there is a lack of statistically evaluated data to support assertions of yield benefits of ZBNF compared to organic or conventional alternatives, or to mechanistically account for them. In order to fill this gap, controlled field experiments were established in twenty-eight farms across six districts, spanning over 800 km, over three cropping seasons. In these experiments, we compared ZBNF (no synthetic pesticides or fertilisers, home-made inputs comprising desi cow dung and urine with mulch) to conventional (synthetic fertilisers and pesticides) and organic (no synthetic pesticides or fertilisers, no mulch, purchased organic inputs, e.g. farmyard manure and vermicompost) treatments, all with no tillage. Comparisons were made in terms of yield, soil pH, temperature, moisture content, nutrient content and earthworm abundance. Our data shows that yield was significantly higher in the ZBNF treatment (z score = 0.58 ± 0.08), than the organic (z= −0.34 ± 0.06) or conventional (−0.24 ± 0.07) treatment when all farm experiments were analysed together. However, the efficacy of the ZBNF treatment was context specific and varied according to district and the crop in question. The ZBNF yield benefit is likely attributed to mulching, generating a cooler soil, with a higher moisture content and a larger earthworm population. There were no significant differences between ZBNF and the conventional treatment in the majority of nutrients. This is a particularly important observation, as intensive use of synthetic pesticides and fertilisers comes with a number of associated risks to farmers’ finances, human health, greenhouse gas emissions, biodiversity loss and environmental pollution. However, long-term field and landscape scale trials are needed to corroborate these initial observations.

Earthworm communities in long-term no-tillage systems and secondary forest fragments in Paraná, Southern Brazil.

The area destined for agricultural production in Paraná state in Brazil is ~6 million hectares, of which 79% are under no-tillage systems (NTS) that can positively affect earthworm populations. Furthermore, earthworm abundance and richness can be valuable soil quality. This study assessed earthworm communities in long-term no-tillage sites (NTS) and nearby secondary Atlantic Forest (SF) fragments. Sampling was performed in June 2018 and May 2019 using the quantitative Tropical Soil Biology and Fertility handsorting method (ISO-TSBF), complemented by qualitative sampling in three municipalities: Faxinal, Mauá da Serra and Palmeira, in NTS and SF. Eleven earthworm species, belonging to five families (Benhamiidae, Glossoscolecidae, Megascolecidae, Ocnerodrilidae, and Rhinodrilidae) were found along with seven native species (Glossoscolex sp.22, Glossoscolex sp.23, Fimoscolex sp.21, Fimoscolex sp.24, Fimoscolex sp.42, Andiorrhinus duseni and Urobenus brasiliensis) and four exotic or cosmopolitan species (Dichogaster gracilis, Amynthas gracilis, Metaphire californica and Pontoscolex corethrurus). The cosmopolitan P. corethrurus dominated Faxinal and Mauá da Serra, while in Palmeira Fimoscolex and Glossoscolex were the most abundant. Six species belonging to Glossoscolex and Fimoscolex were new to science and must be described. Overall, 239 individuals were found. In 2018 126 individuals were found (76 in NTS and 50 in SF) and in 2019, only 112 individuals were found (45 in NTS and 67 in SF). The highest earthworm abundance was in Faxinal (123 individuals), with 76 individuals in NTS and 47 in SF. In Mauá da Serra the same pattern was observed (SF>NTS), while in Palmeira in overall, fewer individuals (38) were collected (24 in NTS and 14 in SF). The NTS at Faxinal and SF Mauá da Serra in 2019 had only/more exotic/cosmopolitan species, while at the other dates and sites >50% of the specimens sampled were native species. Overall, forests had more native species than exotics: in 2018, natives represented > 75% of all specimens, but in 2019 both Faxinal and Mauá da Serra had more exotic species (> 65%), while at Palmeira, they represented 50% of the individuals. Earthworm total biomass for forest sites was higher in Faxinal (3.2 g) and NTS in Mauá da Serra (1.7 g) in 2019. Overall, the total biomass was higher in SF sites than NTS. Using a classification available for earthworm populations in no-tillage systems, all three sites were considered to have poor quality in terms of abundance (ind m-2), while for species richness, they were considered to have moderate (Faxinal and Mauá da Serra) and good quality (Palmeira).

Urban green areas as earthworm species maintainers in Curitiba, Paraná, Brazil.

Urban green areas can have a high impact on soil fauna due the environmental changes caused by human activities. This work aimed to assess earthworm populations in urban sites in the city of Curitiba, Paraná, Brazil. Earthworms were sampled in two urban sites: the Campus Ecoville of the Universidade Positivo and the Casa Verde space and in two land use systems (Grass Lawn and Native Vegetation), in the summer of 2018 and 2019 and winter of 2019. A total of 1052 individuals were found, belonging to five families and 12 species were identified, of which five are native: Glossoscolex sp.55, Fimoscolex sp.36, Fimoscolex sp.37 (Glossoscolecidae), Andiorrhinus duseni (Rhinodrilidae) and Ocnerodrilidae sp.43 (Ocnerodrilidae) and seven are exotic species: Amynthas corticis, Amynthas morrisi, Metaphire californica, Metaphire schmardae (Megascolecidae), Dendrodrilus rubidus (Lumbricidae) and Pontoscolex corethrurus (Rhinodrilidae). Of the five native species found, four are new species and will be described in the future and the specie A. duseni belongs to the group known as giant earthworms (minhocuçu) with specimens larger than 30cm. Despite the predominance of exotic species (n=932) compared to native species (n=114), the presence of new species may indicate that the managed environments can preserve native species. Moreover, the difference in the total number (native vs. exotic) can be attributed to the ability of the exotic species to survive human disturbances.

Earthworm richness in no-tillage farming systems and riparian forests in Southern and Southeastern Brazil

No-tillage (NT) is a soil conservation management practice that can sustain important earthworm populations due the maintenance of soil cover and absence of soil disturbance. Sites with NT can also support native earthworm species, but few studies have identified the earthworms collected under NT. Therefore, the present study evaluated earthworm diversity in 14 sites under NT and seven with riparian forest (RF) in Atlantic Forest located in Rolândia, Cambé, Toledo (Paraná), Coxilha, Sarandi (Rio Grande do Sul) and Itaí (São Paulo). The earthworms were collected by handsorting using quantitative and qualitative methods. The 1471 individuals collected were classified into 23 species belonging to five families: Glossoscolex sp.71, sp.72, sp.73 and sp.74, Fimoscolex sp.23 sp.24 and sp.25 (Glossoscolecidae); Pontoscolex corethrurus, Urobenus brasiliensis (Rhinodrilidae); Haplodrilus sp.1 and sp.2, Ocnerodrilidae sp.1, sp.15, sp.16, sp.48, sp.49 and sp.50 (Ocnerodrilidae); Amynthas gracilis, Metaphire californica (Megascolecidae); Dichogaster affinis, D. gracilis, D. bolaui and D. saliens (Benhamiidae). Of the total, 15 were native and eight were exotic species. In general NT sites had higher species richness than the forest sites (except at Itaí), mainly due to the invasion of NT fields by exotic species, particularly Ocnerodrilidae sp.1 and Dichogaster spp. Six of the seven forests had native species, but only four NT fields had native earthworms, and these were generally found in low abundance.

Recycling and valorization of distilled grape marc through vermicomposting: a pilot-scale study

The present study sought to evaluate the effectiveness of vermicomposting for the valorization of distilled grape marc, one of the main solid by-products of the winery sector during a 56-day pilot-scale trial. The increase in the density and biomass of earthworms (Eisenia andrei) during the earlier stages of the process reflected the suitability of the distilled marc (Vitis vinifera L. cv. Mencía) as feedstock in order to sustain large earthworm populations on a pilot-scale level. Supporting this, from 14 days onwards the pH of Mencía distilled marc fell within weak-alkaline levels and the electrical conductivity was between 0.21 and 0.11 mS cm−2 providing optimum conditions for earthworm growth. A rapid decrease in microbial activity as well as in the content of total polyphenols, both indicative of stabilized materials was also recorded after 14 days of vermicomposting. Moreover, the content of macro- and micronutrients in the end product matched with those considered to have the quality criteria of a good vermicompost with respect to plant health and safe agricultural use. Altogether, it underlines the feasibility of vermicomposting as an environment-friendly approach for the biological stabilization of distilled grape marc fulfilling both environmental protection and fertilizer production.

Ecotoxicity of Single-Use Plastics to Earthworms

The excessive use of plastics in recent years, especially so-called single-use plastics, has led to an incipient increase in the presence of this material in the soil. As soil is the essential production factor in agriculture, this study aims to test the toxicity to earthworms of different concentrations of plastics using the same substrate for each sample. Earthworms are the main bioindicator of soil quality and are of particular ecological value because their disappearance or loss in population would have disastrous consequences for the environment. This study examines the growth, mortality and reproductive cycle of individual earthworms. The species to be studied is Eisenia fetida and during the test, individuals are immersed in five different concentrations: 1 mg/kg; 10 mg/kg; 100 mg/kg; 1000 mg/kg; and 2000 mg/kg. Bioplastic OK industrial compost (that meet the requirements established to comply with compostability according to EN 13432) was used. Whether the plastic in any of those concentrations is harmful to the worm population was then be checked. The test shows the mixture of PLA and PBAT (biodegradable plastic) studied has no significant effect on the population of Eisenia fetida. None of the variables studied yields significant data on this plastic and the effect it causes on the population of earthworms, Eisenia fetida.

Effects of Energy Crop Monocultures and Sewage Sludge Fertiliser on Soils and Earthworm Community Attributes

Biomass is one of the most significant renewable energy sources. Doubts arise from large-area plantations of energy monocultures, which can lead to the depletion of, and a decrease in, soil biodiversity. Community association analyses of Lumbricidae may help to indicate environmental change. Therefore, the study objectives were to determine the qualitative and quantitative diversity of Lumbricids in plantations of energy crops—basket willow (Salix viminalis L.), foxglove tree (Paulownia tomentosa Steud.), and black locust (Robinia pseudoacacia L.)—by investigating the following cultivation treatments: SV and SVSS—S. viminalis without (w/o) and with the addition of sewage sludge to the soil (+SS); PT and PTSS—P. tomentosaw/o and + SS; RP and RPSS—R. pseudoacaciaw/o and +SS; and MW—meadow community. A significantly higher density (p < 0.05) and biomass (p < 0.05) of earthworms were found in the SV and SVSS plantations than in other sites. The application of sewage sludge contributed to a significant increase in the mean number and biomass of all Lumbricids within cultivations of S. viminalis and R. pseudoacacia, which were significantly higher than those in the control site. This work suggests that woody energy crop production with an appropriate selection of plants and fertilisation can be a favourable habitat for the development of earthworm populations.

Earthworms are not just “earth” worms: Multiple drivers to large diversity in deadwood

Earthworms are ecosystem engineers associated with important soil functions. Despite the large amount of literature on earthworm ecology, relatively few studies have examined earthworms in deadwood or quantified their importance in this habitat. We investigated earthworm communities in decaying deadwood and disentangled how their community dynamics are influenced by variation in tree species, wood decomposition stage, and forest environment. Decaying logs (of standardised size) of ten common, temperate tree species were laid out to decay on the soil surface for four years. The experiment was carried out in the “tree cemetery” experiment LOGLIFE, in two contrasting temperate forests in the central Netherlands. The decaying logs yielded surprisingly rich earthworm populations, with on average 19 individuals per meter of log and in total belonging to 12 different species. Our findings highlighted that earthworm communities in deadwood in terms of composition and abundance were influenced by tree species, wood decomposition stage and forest type with different soil properties, as well as their interactions. After one and two years of decay, earthworm abundance was higher in the logs of Picea abies and relatively fast decomposing Populus spp. than in other trees, while this pattern changed after four years with higher earthworm abundance observed in the other tree species. Overall, Populus spp. supported the highest earthworm abundance, followed by Picea abies and Quercus robur. The earthworm community composition in the logs in the two forest sites had broadly similar dynamic trends of first becoming very dissimilar between one and two years, then relatively more similar from two to four years of decay, although the community composition differed between sites. The interacting influences of tree species, wood decay stage and forest environment on earthworm communities strongly suggest that diversity in deadwood resources contributes to earthworm diversity in forests. Thus, by mixing different tree species and logging gradually through the years, forest managers could enhance the diversity of this abundant and understudied component of deadwood invertebrate diversity. Further research should study the feedback loop between earthworm communities and decomposition of deadwood.

Forest Biogeocenoses in the Area of Brown Forest Soils of the Western Caucasus

Vegetation and brown forest soil of different types of forests of the southern and northern macroslopes of the Main Caucasian Ridge were studied, special attention was paid to soil fauna (earthworms), microbial and enzymatic activity. A comparative analysis of the main components of forest biogeocenoses (plant communities, earthworms, microbial and enzymatic activity of the soil) of the southern and northern macroslopes of the Main Caucasian Ridge located in the Caucasian State Natural Biosphere Reserve and natural monuments “Guam Gorge” and “Colchian boxwood Massif” was carried out. The assessment of the plant diversity of various types of colchian forests of the southern and northern macroslopes is given. The similarity of the structure of plant communities, the population of earthworms, their species richness, as well as the most important indicators of the biological activity of the soil of the southern and northern macroslopes has been established. A close correlation between the indicators of biological activity of brown forest soil with the diversity of vegetation and the number of earthworms is shown.

Earthworm Diversity and Their Influences on Soil Enzyme Activities in Organic, Sustainable and Conventional Farming Systems of Puducherry

An experiment was conducted to study the earthworm diversity and its influence on soil enzyme activities in organic, sustainable and conventional farming systems in the state of Puducherry. A total of five earthworm species namely Drawida willsi, Drawida scandens, Lampito mauritii, Perionyx excavates and Eudrilus eugeniae were present in the study sites. Four species were found in conventional and sustainable farming and five species were found in organic farming. Earthworm species diversity, population, species dominance, and biomass were significantly higher in organic farming systems compared to sustainable and conventional farming systems. In addition, soils from organic farming showed higher activity of urease, alkaline phosphatase, β-glucosidase, cellulase, invertase and xylanase activities and they had a significant positive correlation with earthworm population and biomass. Our results revealed that the presence of earthworms strongly affected enzyme activities in soil. Earthworm casts probably contributed to the enrichment of plant-available nutrients and higher soil enzyme activities in organically managed soils.

Insights into the molecular mechanisms of pesticide tolerance in the Aporrectodea caliginosa earthworm

Diffuse pollution of the environment by pesticides has become a major soil threat to non-target organisms, such as earthworms for which declines have been reported. However some endogeic species are still abundant and persist in intensively cultivated fields, suggesting they become tolerant to long-term anthropogenic pressure. We thus considered the working hypothesis that populations of Aporrectodea caliginosa earthworms from conventionally managed fields developed a tolerance to pesticides compared with those from organically managed fields. To investigate this hypothesis, we studied earthworm populations of the same genetic lineage from soils that were either lowly or highly contaminated by pesticides to detect any constitutive expression of differentially expressed molecular pathways between these populations. Earthworm populations were then experimentally exposed to a fungicide—epoxiconazole—in the laboratory to identify different molecular responses when newly exposed to a pesticide. State-of-the-art omics technology (RNA sequencing) and bioinformatics were used to characterize molecular mechanisms of tolerance in a non-targeted way. Additional physiological traits (respirometry, growth, bioaccumulation) were monitored to assess tolerance at higher levels of biological organization. In the present study, we generated the de novo assembly transcriptome of A. caliginosa consisting of 64,556 contigs with N50 = 2862 pb. In total, 43,569 Gene Ontology terms were identified for 21,593 annotated sequences under the three main ontologies (biological processes, cellular components and molecular functions). Overall, we revealed that two same lineage populations of A. caliginosa earthworms, inhabiting similar pedo-climatic environment, have distinct gene expression pathways after they long-lived in differently managed agricultural soils with a contrasted pesticide exposure history for more than 22 years. The main difference was observed regarding metabolism, with upregulated pathways linked to proteolytic activities and the mitochondrial respiratory chain in the highly exposed population. This study improves our understanding of the long-term impact of chronic exposure of soil engineers to pesticide residues.

Radium uptake by earthworms E. fetida after exposure to contaminated soil

Radium-226 is one of the most important radionuclides for assessing the radiation exposure in terrestrial ecosystems in terms of its significant contribution to the internal and total dose rates. A laboratory culture of Eisenia fetida was exposed to soil contaminated with 226Ra and 238U during two months. These nuclides entered the soil as a result of industrial radium production (Vodny, Komi Republic, Russia). The concentrations of 226Ra and 238U were 89000 ± 9000 and 2130 ± 270 Bq kg−1 of soil. Bioaccumulation of 226Ra was investigated in E. fetida exposed to the radioactive soil or to a mixture containing the same radioactive soil diluted with peat and sand. The activity concentrations of 226Ra in E. fetida were higher after exposure to the contaminated soil compared to the mixture. The literature data on the radium accumulation in earthworms were considered also. Our experiments showed that the concentration ratio (CR) of 226Ra in E. fetida varied from 5.5 × 10−4 to 4.5 × 10−3 Bq kg−1 f.w./Bq kg−1 d.w. The average CRs were (6.7 ± 1.7) × 10−4 for the earthworms E. fetida from the soil mixture and (3.2 ± 1.2) × 10−3 for those from the radioactive soil. These CRs for 226Ra were up to two orders of magnitude lower than the values calculated by us from the results obtained by other researchers for natural earthworm populations in areas with lower levels radioactivity.

Genetic variability of earthworm populations in soils with different perturbation levels

Density and genetic variability of both soil macro- and meso-fauna are disturbed by productive practices. This study aimed to analyze the genetic diversity and genetic structure of populations of the earthworm Aporrectodea caliginosa caliginosa (Briones, 1996) in two sites of the Argentine Pampa under different levels of disturbance: i) grassland, ii) livestock-raising plot, iii) agricultural-livestock raising plots and iv) agricultural plot (the most disturbed). The genetic diversity of the earthworm population was determined based on the allele number, polymorphism percentage and Similarity Index. Allele number and polymorphism percentage were lower in populations from one of the soils under agricultural-livestock practices, but differed significantly only from the values of the other agricultural-livestock raising plot and the livestock-raising plot. Population structure was low although significant. This study shows that allele number and polymorphism are very useful metrics to provide historical and functional information of soils. However, the genetic differences here recorded probably depend on multiple historical and recent causes. The stability of environmental conditions along with the degree of disturbance must be considered to understand their impact on population genetic structure.

The use of banana peel as feed to increase growth of earthworms (Lumbricus rubellus)

Research on using banana peels as feed to increase the growth of Lumbricus rubellus has been carried out. This study aims to determine: (1) the effect of different doses of banana peel pulp on feed on the growth of earthworms (Lumbricus rubellus), (2) the best dose of banana peel pulp to increase the growth of earthworms. This research is a one-factor study. The research was carried out with five levels of treatment and five replications. The doses of banana peel pulp are 0 ml, 250 ml, 500 ml, 750 ml, and 1000 ml. The parameters of the growth of earthworms measured were the addition of the number of individuals and the addition of the weight of the earthworm population. The research data were analyzed by analysis of variance. The research results show that: (1) the difference in the dose of banana peel pulp significantly affected the increase in the number of individuals and the weight of the earthworm population; (2) the addition of 1000 ml of banana peel pulp resulted in the highest number of individuals and the heaviest population weight compared to other treatment doses.

Straw incorporation interacting with earthworms mitigates N2O emissions from upland soil in a rice-wheat rotation system

Intensive attentions have been paid to the positive effects on nitrous oxide (N2O) production under straw return or the presence of earthworms. Straw return as a sustainable practice can promote earthworm growth, how the interactions between straw and earthworms affect N2O production is still not well known. A split-plot field experiment (straw return as main plot and earthworm addition as subplot) was performed to quantify the interactive effects of straw and earthworm on N2O emissions from a wheat field and to determine the underlying mechanisms from nitrification and denitrification processes. The results showed that straw return significantly increased N2O emissions by 41.0 % under no earthworm addition but decreased it by 19.0 % under earthworm addition compared with straw removal (P < 0.05). The significant interaction between straw and earthworm benefits the mitigation of N2O emissions. Random forest model showed that denitrification and nitrification were dominant processes to affect N2O emissions at the jointing and booting growth stages of wheat, respectively. The interaction between straw and earthworm significantly decreased the abundances of N2O-producing bacterial genes such as nirS and nirK at the jointing stages, and AOB at the booting stages. The contrasting mechanisms in regulating N2O emissions at different growth stages should be considered in nitrogen recycling models to accurately predict available N and N2O dynamics. Our findings suggest that N2O emissions under straw return can be weakened with the increasing earthworm populations under the scenario of widely used conservation practices (e.g., straw return and no-till) due to significant interaction between straw and earthworms.

Earthworm stocking density regulates microbial community structure and fatty acid profiles during vermicomposting of lignocellulosic waste: Unraveling the microbe-metal and mineralization-humification interactions

Earthworm-induced microbial enrichment is the key to success in vermitechnology, yet the influence of initial earthworm stocking density on microbial community profiles in vermibeds is unknown. Therefore, vermicomposting of lignocellulosic feedstock was performed with different stocking densities of two earthworms (Eisenia fetida and Eudrilus eugeniae) compared with composting. Eventually, earthworm growth, microbial (activity and community profiles), and physicochemical dynamics were assessed. The earthworm population significantly increased under low stocking, while denser stocking (15/kg) was stressful. The XRD-based crystallinity assessment revealed that comminuting efficiency of Eisenia and Eudrilus was prudent at 7 and 10 worm/kg stockings, respectively. Moreover, the 5 and 7 worm/kg stockings effectively mobilized microbial activity, promoting NPK-mineralization and C-humification balance. Correlation statistics indicated that earthworm stocking density-driven microbial community shift and fatty acid profiles strongly influenced metal removal in vermibeds. Hence, the findings implied that 5–7 worm/kg stockings of earthworms produced high-quality sanitized vermicompost.

Earthworm Lumbricus terrestris Contributes Nitrous Oxide Emission from Temperate Agricultural Soil Regardless of Applied Mineral Nitrogen Fertilizer Doses

Agriculture is the main contributor to nitrous oxide (N2O) emission, but the emission intensity can be controlled by various factors, in particular, the activity of earthworms, one of the most common groups of soil invertebrates. We conducted an incubation experiment to evaluate N2O emission in earthworm soil samples compared to non-earthworm ones with applications of high (200 kg ha−1) and low (50 kg ha−1) mineral N fertilizer doses. We assessed the cumulative N2O emission, the dynamics of the soil dissolved organic carbon, and the soil microbial carbon and nitrogen content, as well as the number of nirK and nirS gene copies in bulk soil samples and in isolates from the earthworms’ gut. Our study showed a significant role of the earthworm activity in changing the intensity of N2O emission after the application of mineral N fertilizers. The main factor leading to an increase in nitrous oxide emission in the presence of earthworms is the stimulation of free-living soil denitrifiers by the organic matter of the earthworms’ excretions, as well as the thorough mixing of plant residues and soil. Contrary to our expectations, earthworms did not increase the representation of nitrite reductase genes in soil, although the earthworm’s gut can be considered as a refugium for denitrifiers. Our results indicate a possible risk of increased N2O emission from arable temperate soils with an increase in earthworm populations as the climate warms, even if application rates of mineral fertilizers are reduced.