Earthworm Abundance Research Articles

Toxicity of ivermectin residues in aged farmyard manure to terrestrial and freshwater invertebrates

Abstract Farmyard manure is often stored, aged and spread on fields as fertiliser; however, dung may be contaminated with residues of veterinary endectocides used to treat livestock for parasites. The persistence of these chemicals during storage and impact on invertebrate biodiversity after spreading are not well understood. This study considered whether residues in aged cattle manure could have impacts on terrestrial and freshwater invertebrate biodiversity and ecosystem function. Fresh cattle dung was spiked with known concentrations of the endectocide ivermectin or an excipient only (control) and aged in the field for 4 months between February and May 2020. Each month rainwater run‐off was collected and used to examine toxicity using the freshwater invertebrate Daphnia magna. In June 2020, manure was spread on mesocosms containing topsoil, and above‐ground insect emergence, soil fauna feeding rate, earthworm abundance and pasture productivity (perennial ryegrass growth), were measured over 10 weeks. Rainwater‐runoff from manure contaminated with ivermectin was highly toxic (60–100% mortality) to D. magna for the entire 4 months of storage. Coleoptera and Diptera emergence was lower from mesocosms spread with ivermectin‐contaminated manure compared with control manure. Pasture productivity was significantly lower (18–20%) in mesocosms spread with ivermectin‐contaminated manure. The results indicate that ivermectin residues aged manure have the potential to retain toxic effects on terrestrial and freshwater invertebrates for at least 4 months of storage, could reduce pasture productivity, and may have pervasive impacts on invertebrate biodiversity in agricultural systems.

Earthworm species occurrence in agroecosystems in the Midlands, KwaZulu-Natal, South Africa

Little is known about the species composition of earthworms in agroecosystems in South Africa even though earthworms provide soil ecosystem services and are useful biological indicators of changes in the habitats. Given the land use and management impact biodiversity, the aim of this study was to document earthworm species that occur under cultivated land in the KwaZulu-Natal Midlands. A survey of nine farms that practise conservation agriculture was carried out between 2018 and 2020. Twelve earthworm species belonging to four introduced families: Acanthodrilidae (Dichogaster bolaui), Rhinodrilidae (Pontoscolex corenthrurus), Lumbricidae (Aporrectodea caliginosa,Aporrectodea rosea,Aporrectodea trapezoides,Lumbricus rubellus,Octolasion cyaneum,Octolasion lacteum), Megascolecidae (Amynthas aeruginosus,Amynthas corticis,Amynthas gracilis,Amynthas rodericensis) and juveniles from an indigenous family Tritogeniidae were recorded from cultivated fields. The type of crop (habitat) affected both species richness and abundance of earthworms significantly. However, post hoc results showed differences in species richness between the soya and the maize only, with greater species richness in the maize. Our results demonstrate that habitat type has a major influence on communities of earthworms in agroecosystems.

Regenerative Almond Production Systems Improve Soil Health, Biodiversity, and Profit

Regenerative agriculture aims to improve soil health and promote biodiversity while producing nutritious food profitably. Almonds are the dominant crop in California agriculture in terms of acreage and revenue generated. We examined the soil health, biodiversity, yield, and profit of regenerative and conventional almond production systems that represented farmer-derived best management practices. Regenerative practices included abandoning some or all synthetic agrichemicals, planting perennial ground covers, integrating livestock, maintaining non-crop habitat, and using composts and compost teas. Total soil carbon (TSC), soil organic matter (SOM), total soil nitrogen (TSN), total soil phosphorous, calcium, sulfur, and soil health test scores were all significantly greater in regenerative soils. Water infiltrated regenerative soils six-fold faster than conventional soils. Total microbial biomass, total bacterial biomass, Gram+ bacteria, and Actinobacteria were significantly greater in regenerative soils. There was more plant biomass, species diversity, and percent cover in regenerative orchards. Invertebrate richness and diversity, and earthworm abundance and biomass were significantly greater in regenerative orchards. Pest populations, yields, and nutrient density of the almonds were similar in the two systems. Profit was twice as high in the regenerative orchards relative to their conventional counterparts. No one practice was responsible for the success of regenerative farms; their success was the result of simultaneously combining multiple regenerative practices into a single, functional farm system. This style of farming may assist in combatting planetary scale problems (e.g., climate change, biodiversity loss, agricultural pollution, chronic human health problems, and declining rural communities) while making farms more profitable and resilient.

Short- and long-term impacts of anaerobic digestate spreading on earthworms in cropped soils

Anaerobic digestion is increasingly used in Europe to treat organic substrates and produce biogas as a renewable energy source. The residual matter (digestate) is used in agriculture as an organic fertilizer. The study aims at assessing the impact of digestate application in the field on earthworms from the short term (few hours) to the long term (two years), and at investigating under laboratory conditions the role of ammonia and earthworm behavior on digestate toxicity in the short term. First, we studied earthworm communities in fields fertilized with digestates, cattle effluents, or chemical fertilizers for two years. Earthworm abundance was assessed before and after the fertilization event of the third year. Earthworm mortality at the soil surface was also assessed immediately after fertilization. Next, the toxicity of digestate or ammonia solutions on Aporrectodea caliginosa and Lumbricus terrestris was measured in microcosms (110 cm3) to better understand the short-term toxicity (two weeks). Finally, we spread digestate (40–80 t ha−1) on soil columns (5300 cm3) and used X-ray tomography after two weeks to assess the burrowing behavior of earthworms in the cores. Earthworm abundance was 150% higher in the fields treated for two years with digestates or cattle effluents compared to the field treated with chemical fertilizers. 0.5 to 2% of adult earthworms died at the soil surface a few hours after liquid digestate and cattle slurry spreading (18 to 24 t ha−1). The digestate (10% to 20% (fresh digestate/dry soil)) and ammonia were also lethal to earthworms in the microcosms within two weeks. In contrast, no mortality occurred inside soil columns two weeks after digestate spreading; A. caliginosa avoided the soil surface with high digestate inputs. This case study highlighted the potential short-term toxicity of digestate (a few hours), which evolved towards a neutral to positive impact in the field in the longer term (from two weeks to two years). Further research is needed to understand the impact of diverse solid and liquid digestates on soil macrofauna in different soils.

Hardwood mixture enhances soil water infiltration in a conifer plantation

Soil hydraulic properties affect soil infiltration capacity. Limited information is available about how hardwood mixture influences water infiltration in conifer plantations through its effects on soil hydraulic properties. We evaluated how, and to what extent, infiltration rates were affected by abiotic and biotic conditions along gradients of abundance and diversity of hardwoods and abundance of understory plants in nine stands representing three replicates of three different thinning intensities (unthinned [Control], 33% thinning [Weak], and 67% thinning [Intensive]) in a Cryptomeria japonica (Thunb. ex L. f.) D. Don plantation. Correlation analyses and a structural equation model (SEM) indicated that infiltration rates were enhanced by hardwood mixture (i.e., abundance and species richness of hardwoods) and abundance of understory plants, via increases in the fine root density and accumulation of broadleaf litter, because the fine root density decreased soil bulk density and accumulation of litter increased the porosity and both of which greatly improved the soil hydraulic conditions. In the Intensive treatment, complementarity effects stemming from vertical partitioning of resource acquiring organs (i.e., leaves) among species might have increased accumulation of broadleaf litter. If increased volumes of broadleaf litter promote increased earthworm abundance, earthworms may in turn cause higher porosity, because the burrowing activity of earthworms increases the number of macropores. Consequently, hardwood mixture with abundant understory plants promotes increased infiltration rates. Our results demonstrate that intensively thinned stands with an abundance and diversity of hardwoods, including broadleaf understory plants, can absorb and store more water compared to lightly thinned stands with only understory plants, owing to increased soil infiltration capacity. Our results point to the importance of hardwood mixture in enhancing ecosystem functioning in conifer plantations.

Over winter cover crops provide yield benefits for spring barley and maintain soil health in northern Europe

A three-year field experiment investigated the potential yield benefits and soil effects from over winter cover crops in Scotland, U.K. Brassica composition of cover crops significantly increased the grain yield and grain nitrogen (N) concentration of the following spring barley crop. The increased yield with cover crops was outweighed by increased costs and thus without subsidy (Ecological Focus Area) payments there was decreased profitability for the following spring barley crop. Cover crop effects were mostly neutral on soil properties, but surface shear strength was significantly lower than in the stubble control. This indicates that even direct drilling of cover crops will loosen the surface soil. Cover crops varied in their effect on slug populations but in all cases slug numbers were below treatment thresholds. No cover crop effects were detected for total nematode and earthworm abundance or the total soil organic carbon concentration. This study indicates that cover crops can improve cereal production in a region with a short growing season with no negative impact on soil health or the agronomic sustainability.

Effect of Cogongrass (Imperata cylindrica L.) root extract on earthworms, arbuscular mycorrhizae fungi spore, and growth of upland rice (Oryza sativa L.) for local Kambowa variety

Earthworms have the ability to create new conditions in the soil environment and modulate the growth of beneficial soil microbial populations. Imperata releases exudate which creates less suitable soil conditions for growing food crops and horticulture. This study aims to: (i) study the effect of the concentration of cogongrass root extract on the abundance of earthworms and arbuscular mycorrhizal fungi spores-(ii) to determine the effect of the soil-extract mixture engineered using earthworms on the upland rice growth for local Kambowa variety. The first experiment, extracts of cogongrass roots were made into five concentration levels, namely 0%, 20%, 40%, 60%, and 80%. Each concentration was mixed with soil from cogongrass land in a different vermireactor. In reactor, earthworms were released that had emptied their stomach contents, and were allowed to manipulate the mixture until the vemicast covered part of the soil surface. As a result, the total earthworms in all reactors were relatively the same, and the total spores of arbuscular mycorrhizal fungi in the soil treated with a concentration of 60% was the most. The second experiment, the upland rice seedlings were grown on engineered soils. The differences in height, leaf area, number of tillers, panicle length, and total spikelet’s per panicle were significantly, except for leaves number, wet weight, dry weight, and percentage of spikelet filled. In conclusion, earthworms as potential ecosystem engineers are utilized in ecological engineering of soil quality in land dominated by reeds vegetation for the development of upland rice cultivation areas, particularly the local varieties of Kambowa.

Earthworm Abundance Changes Depending on Soil Management Practices in Slovenian Vineyards

Earthworms are key indicators of soil quality and health in vineyards, but research that considers different soil management systems, especially in Slovenian viticultural areas is scarce. In this investigation, the impact of different soil management practices such as permanent green cover, the use of herbicides in row and inter-row areas, use of straw mulch, and shallow soil tillage compared to meadow control for earthworm abundance, were assessed. The biomass and abundance of earthworms (m2) and distribution in various soil layers were quantified for three years. Monitoring and a survey covering 22 May 2014 to 5 October 2016 in seven different sampling dates, along with a soil profile at the depth from 0 to 60 cm, were carried out. Our results showed that the lowest mean abundance and biomass of earthworms in all sampling periods were registered along the herbicide strip (within the rows). The highest abundance was found in the straw mulch and permanent green cover treatments (higher than in the control). On the plots where the herbicide was applied to the complete inter-row area, the abundance of the earthworm community decreased from the beginning to the end of the monitoring period. In contrast, shallow tillage showed a similar trend of declining earthworm abundance, which could indicate a deterioration of soil biodiversity conditions. We concluded that different soil management practices greatly affect the soil’s environmental conditions (temperature and humidity), especially in the upper soil layer (up to 15 cm deep), which affects the abundance of the earthworm community. Our results demonstrated that these practices need to be adapted to the climate and weather conditions, and also to human impacts.

Response of earthworm communities to soil engineering and soil isolation in urban landscapes

Engineered soils provide numerous ecosystem services in urban landscapes, such as water regulation and plant growth. They are constructed to optimize soil physicochemical properties but their biological properties are given little consideration. In particular, earthworm communities may be highly impacted by soil engineering processes and soil isolation caused by asphalted surfaces separating soils, and in particular roadside soils, from pseudo-natural soils. In this context, this study aimed to evaluate (i) the effects of soil engineering processes applied to construct roadside soils, and (ii) the effects of soil isolation from pseudo-natural soils by asphalted surfaces on earthworm communities. The study was conducted in an urban landscape in the suburbs of Paris, France. We sampled earthworms in roadside soils from two distinct soil engineering processes: basic engineering (BER) associated with shallow stripping depth and advanced engineering (AER) associated with deep stripping depth and organic amendment. Within each soil engineering process, two levels of soil isolation were defined depending on the asphalted surface separating roadside soils from pseudo-natural soils: light isolation (LI) in case of a narrow cycle path, and high isolation (HI) in case of a wide road. Soil engineering did not affect the total earthworm abundance whereas the total species richness was negatively impacted in comparison to nearby pseudo-natural soils. High soil isolation differently impacted earthworm communities depending on the engineering process. Regarding AER, earthworm abundance and species richness were significantly lower in HI than in LI while no differences were observed between BER-LI and BER-HI. Overall, engineering processes define the soil's ability to host earthworms, and soil isolation defines soil ability to be colonized from nearby environments. Considering the contribution of earthworms to the provision of ecosystem services, both soil engineering and soil isolation should be taken into account in urban projects to optimize their development in urban landscapes.

Land‐use intensity and biodiversity effects on infiltration capacity and hydraulic conductivity of grassland soils in southern Germany

AbstractEvidence from experimental and established grasslands indicates that plant biodiversity can modify the water cycle. One suspected mechanism behind this is a higher infiltration capacity (νB) and hydraulic conductivity (K) of the soil on species‐rich grasslands. However, in established and agriculturally managed grasslands, biodiversity effects cannot be studied independent of land‐use effects. Therefore, we investigated in established grassland systems how land‐use intensity and associated biodiversity of plants and soil animals affect νB and K at and close to saturation. On 50 grassland plots along a land‐use intensity gradient in the Biodiversity Exploratory Schwäbische Alb, Germany, we measured νB with a hood infiltrometer at several matrix potentials and calculated the saturated and unsaturated K. We statistically analysed the relationship between νB or K and land‐use information (e.g., fertilising intensity), abiotic (e.g., soil texture) and biotic data (e.g., plant species richness, earthworm abundance). Land‐use intensity decreased and plant species richness increased νB and K, while the direction of the effects of soil animals was inconsistent. The effect of land‐use intensity on νB and K was mainly attributable to its negative effect on plant species richness. Our results demonstrate that plant species richness was a better predictor of νB and K at and close to saturation than land‐use intensity or soil physical properties in the established grassland systems of the Schwäbische Alb.

Biochar amendment improves soil physico-chemical properties and alters root biomass and the soil food web in grazed pastures

Biochar application has been recognised as an effective way to improve soil functions. In this study, we investigated how adding biochar as an amendment affects soil biological and physico-chemical properties in grazed pastures in a one-year field-based mesocosm experiment conducted on two contrasting soils – a sil-andic Andosol and a dystric Cambisol. Each site had two pastures managed under different nutrient and livestock practices: with and without effluent under dairy cow grazing on the Andosol, and with either nil or high phosphorus (P) fertiliser input under sheep grazing on the Cambisol. The soil amendment treatments were: (i) willow biochar produced at 350 °C (1% w/w); (ii) lime, added at the liming equivalence of the biochar application (positive control); (iii) no amendments (negative control). With few exceptions, after 12 months and compared with initial values and controls, biochar caused (i) an increase in soil total nitrogen (N) and Olsen P content (all P < 0.005) beyond those expected from the N and P added with biochar; (ii) decrease in soil bulk density (P < 0.005), on average by 7%, more than can be explained by the reduced density of the biochar added; (iii) increase in microbial biomass C (P < 0.005), and (iv) increase in root biomass by 6.9 Mg ha−1 (P < 0.005). Lime addition increased pH values in both soils under all four management practices, and increased earthworm abundance compared with controls across all sites. In biochar-amended soils, earthworm abundance was higher only in the Andosol without effluent (P < 0.05), while Collembola abundance was significantly higher (P < 0.005) than the controls in all pastures; there was no effect on soil Oribatida and Gamasina populations. Adding biochar made from willow wood produced at low temperature to these pasture soils can positively affect the soil structure, nutrient cycling, and stimulate root growth, a key contributor to organic C input to the soil and the soil food web.

Assessment of Earthworm Community Structure in Industrial and Non-industrial Soils

The trend of industrialization in all over the world significantly altered the assemblages of species and their surrounding environments in the soil. In the present study, the earthworm community structures were assessed in the industrial and non-industrial soils. Total seven earthworm species i.e. Amynthas morrisi (Beddard), Lampito mauritii (Kinberg), Metaphire posthuma (Vaillant) and Polypheretima elongata (Perrier) belonging to family Megascolecidae while Eutyphoeus incommodus (Beddard), Eutyphoeus waltoni (Michaelsen) and Octochaetona beatrix (Beddard) belonging to family Octochaetidae were reported. It was also reported that the earthworm species, their abundance and biomass was significantly (p < 0.05) higher in non-industrial soils as compared to industrial soils. The Metaphire posthuma was reported as the most abundant earthworm species in both industrial and non-industrial soils. The diversity indices such as the Shannon-Wiener diversity index, Simpson index of diversity and species richness index were higher in non-industrial soils while the Simpson index and species evenness index were high in industrial soils. The soil properties such as pH, EC, TDS and heavy metals content were much higher in the industrial soils and significant negative correlation of above said soil properties with earthworm ecological characteristics. This study can be considered as indication that industrialization has much more negative effects on the earthworms and their community structures.

Effect of the 32nd-year Soil Tillage and Nitrogen Fertilization on the Population and Biomass of Earthworm under Zea mays L.

The abundance and biomass of earthworms are affected by soil tillage and fertilization. This research aimed to study long-term 32nd-year soil tillage and nitrogen fertilization on the population and biomass of earthworms under Zea mays L. The research was conducted using a randomized block design (RBD) which consisted of two factors. The first factor was the soil tillage that was Intensive Tillage (IT), Minimum Tillage (MT), and No-Tillage (NT). The Second factor was nitrogen fertilization that was N0 = 0 kg N ha-1 and N1= 200 kg N ha-1. Data of earthworm population and biomass were tested using analysis of variance and continued with the least significant difference (LSD) test at the 95% significant level. The population and biomass of earthworms at MT or NT were higher than IT. The population and biomass of earthworms in the plots without fertilization were higher than those at 200 kg N ha-1. There was an interaction between the soil tillage and N fertilization on earthworm biomass observed 60 days after planting at a 0-10 cm depth. There was a positive correlation between soil pH and earthworm population and biomass before the tillage phase.

Arable fields as potential reservoirs of biodiversity: Earthworm populations increase in new leys

Managing soil to support biodiversity is important to sustain the ecosystem services provided by soils upon which society depends. There is increasing evidence that functional diversity of soil biota is important for ecosystem services, and has been degraded by intensive agriculture. Importantly, the spatial distribution of reservoirs of soil biota in and surrounding arable fields is poorly understood. In a field experiment, grass-clover ley strips were introduced into four arable fields which had been under continuous intensive/conventional arable rotation for more than 10 years. Earthworm communities in arable fields and newly established grass-clover leys, as well as field boundary land uses (hedgerows and grassy field margins), were monitored over 2 years after arable-to-ley conversions. Within 2 years, earthworm abundance in new leys was 732 ± 244 earthworms m−2, similar to that in field margin soils (619 ± 355 earthworms m−2 yr−1) and four times higher than in adjacent arable soil (185 ± 132 earthworms m−2). Relative to the arable soils, earthworm abundance under the new leys showed changes in community composition, structure and functional group, which were particularly associated with an increase in anecic earthworms; thus new leys became more similar to grassy field margins. Earthworm abundance was similar in new leys that were either connected to biodiversity reservoirs i.e. field margins and hedgerows, or not (installed earthworm barriers). This suggests that, for earthworm communities in typical arable fields, biodiversity reservoirs in adjacent field margins and hedgerows may not be critical for earthworm populations to increase. We conclude that the increase in earthworm abundance in the new leys observed over 2 years was driven by recruitment from the existing residual population in arable soils. Therefore, arable soils are also potential reservoirs of biodiversity.

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.

Response of boreal clay soil properties and erosion to ten years of no-till management

We compared soil physical, chemical and biological properties, erosion rate and carbon allocation to soil physical fractions between conventional tillage (CT) and no-till (NT) management at a clay soil site under spring cereal monoculture in southwestern Finland. Subsurface drain discharge, surface runoff and soil erosion were continuously monitored in 2008 − 2018. At the end of the 10-year monitoring period in 2018, various soil properties and earthworm total density, mass and species richness were determined. Total soil erosion was 56 % less in NT than in CT although surface water discharge was higher in NT. NT had a clear effect on the topsoil physical structure by decreasing the pore size and increasing soil aggregate size. The total soil carbon stock in the 700 kg m−2 mineral topsoil layer (approx. 0−60 cm layer) was slightly lower in NT (108 ± 12 Mg C ha-1) than in CT (118 ± 9.0 Mg C ha-1) due to lower carbon content of the 10−30 cm layer in NT. In NT the proportion of large macroaggregates was higher and more organic carbon was bound to large macroaggregates in the 0−10 cm layer which may be related to the higher abundance of earthworms in NT. The results showed that NT is an effective method to reduce erosion rates but other means to increase carbon input especially below the topsoil layer are likely required to achieve a significant increase in the carbon stock of boreal clay soils. For both tillage managements, the rate of erosion through subsurface drains depended clearly on annual precipitation and winter temperature, posing a challenge in the future climate with mild winters and more extreme discharges.

Vibrational noise from wind energy‐turbines negatively impacts earthworm abundance

Human activities often impact the sensory environment of organisms. Wind energy turbines are a fast‐growing potential source of anthropogenic vibrational noise that can affect soil animals sensitive to vibrations and thereby alter soil community functioning. Larger soil animals, such as earthworms (macrofauna, &gt; 1 cm in size), are particularly likely to be impacted by the low‐frequency turbine waves that can travel through soils over large distances. Here we examine the effect of wind turbine‐induced vibrational noise on the abundance of soil animals. We measured vibrational noise generated by seven different turbines located in organically‐farmed crop fields in the Netherlands. Vibratory noise levels dropped by an average of 23 ± 7 dB over a distance of 200 m away from the wind turbines. Earthworm abundance showed a strong decrease with increasing vibratory noise. When comparing the nearest sampling points in proximity of the wind energy turbines with the points furthest away, abundance dropped on average by 40% across all seven fields. The abundance of small‐sized soil animals (mesofauna, &lt; 10 mm in size) differed between crop fields, but was not related to local noise levels. Our results suggest that anthropogenic vibratory noise levels can impact larger soil fauna, which has important consequences for soil functioning. Earthworms, for instance, are considered to be crucial ecosystem engineers and an impact on their abundance, survival and reproduction may have knock‐on effects on important processes such as water filtration, nutrient cycling and carbon sequestration.

Management Influence on the Quality of an Agricultural Soil Destined for Forage Production and Evaluated by Physico-Chemical and Biological Indicators

The European Common Agricultural Policy promotes the sustainable use of soils through the principle of cross-compliance that links direct payments to good farming practices. Thus, it is necessary to find sustainable alternatives to the conventional management for forage production in the Atlantic Arc dairy farms. Two alternative managements (faba bean in monoculture—FB—and faba bean–Italian ryegrass intercrop—FBIR) were cultivated with organic fertilization during two consecutive years, and compared to the conventional management (Italian ryegrass in monoculture—IR—under chemical fertilization) as winter crops. Maize was used as the summer crop to complete the rotations using organic and chemical fertilization, respectively. The forage yield of winter fodder was quantified. Soil samples and summer harvests were performed to analyse the physico-chemical and biological parameters. The best forage yield corresponded to FBIR with 9.2 t dry matter (DM) ha−1 vs. 7.2 and 5.7 t DM ha−1 for FB and IR, respectively. The soil organic matter did not show significant differences among treatments, suggesting that it may be a poor indicator of the management influence on edaphic quality in the short term. Biological indicators were more sensitive and faster to differentiate among managements than chemical indicators. Earthworm abundance was higher in FB and FBIR than IR (p &lt; 0.001), and consequently, soil infiltration was improved with the alternative management (13.90 vs. 2.08 and 0.90 min for IR, FB and FBIR, respectively, p &lt; 0.01). As a result, the soil health diagnosis of the agroecosystem was better for alternative management.

Oil palm and rubber expansion facilitates earthworm invasion in Indonesia

Deforestation, plantation expansion and other human activities in tropical ecosystems are often associated with biological invasions. These processes have been studied for above-ground organisms, but associated changes below the ground have received little attention. We surveyed rainforest and plantation systems in Jambi province, Sumatra, Indonesia, to investigate effects of land-use change on the diversity and abundance of earthworms—a major group of soil-ecosystem engineers that often is associated with human activities. Density and biomass of earthworms increased 4—30-fold in oil palm and rubber monoculture plantations compared to rainforest. Despite much higher abundance, earthworm communities in plantations were less diverse and dominated by the peregrine morphospecies Pontoscolex corethrurus, often recorded as invasive. Considering the high deforestation rate in Indonesia, invasive earthworms are expected to dominate soil communities across the region in the near future, in lieu of native soil biodiversity. Ecologically-friendly management approaches, increasing structural habitat complexity and plant diversity, may foster beneficial effects of invasive earthworms on plant growth while mitigating negative effects on below-ground biodiversity and the functioning of the native soil animal community.

Three-Year Investigation of Tillage Management on the Soil Physical Environment, Earthworm Populations and Crop Yields in Croatia

The aim of this study was to determine the environmental suitability of conservation tillage systems. A 3-year experiment was conducted in Croatia, to study the effects of different tillage treatments on soil properties, with the following: deep (DC), shallow tine cultivation (SC) and ploughing (P). Soil penetration resistance (SPR) was significantly greater in P compared to DC in all three years. In 2016, it was found at 30–40 and 40–50 cm; in 2017 at 10–20 cm; in 2018 at 0–10 and 10–20 cm. However, SC was significantly greater at 20–30, 30–40 and 40–50 cm compared to P and DC in 2017. The greater surface coverage in DC and SC (&gt;30%) as compared to P (&lt;1%) provided significantly higher soil moisture content (SMC) in maize (2016) and soybean (2018). In 2017, SMC in SC was significantly lower than in P and DC. Regarding all the 3 years, the agronomic structure in DC and SC had significantly greater crumb ratio compared to P, whereas P had significantly higher dust ratio than DC and SC. Throughout the 15 measurements, DC provided the most favorable soil habitat (11 occasions out of 15). In 2017, the earthworm abundance was significantly higher in DC compared to SC. In all the three years, DC resulted the highest yield, however the difference was not significant. Higher surface coverage and SMC positively impacted the ratio of agronomic structure (decreased dust and increased crumb ratio) and earthworm abundance. It can be concluded that DC and SC provided greater soil coverage which positively affected SPR, SMC, agronomic structure and earthworm abundance as compared to P.