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Mechanical soil disturbance is one among the key factors influencing soil biodiversity in agriculture. Although many soil organisms are sensitive to soil disturbance, fungi could be highly impacted due to their sessile lifestyle, relatively slow growth and filamentous body structure. Arbuscular mycorrhizal (AM) fungi are of particular interest in arable lands, providing crop plants with numerous vital services such as nutrient acquisition and protection against abiotic and biotic stressors. Considering this, tillage practices that aim to reduce soil disturbance are often seen as a fungal‐friendly alternative to conventional inversion tillage. Although local studies exist on the impacts of minimal tillage practices on AM fungi, the universality of this approach has been debated. Our objective was to assess the effects of reduced tillage intensity on AM fungi in comparison with conventional tillage. Using high‐throughput sequencing techniques in long‐term field experiments in five European countries, we show that the effects of reduced tillage intensity may not necessarily be positive on soil AM fungal diversity. Plots which were tilled using reduced tillage techniques had lower AM fungal richness in three countries, whereas in one of them, no significant differences were found. We also observed a shift in AM fungal communities where prevalence of taxa preferring root colonisation rather than soil exploration increased under reduced tillage regimes. Here, we argue that more detailed and long‐term studies are needed to understand the factors that could make the reduction of soil disturbance more beneficial to AM fungi if agricultural sustainability goals are to be met. [ABSTRACT FROM AUTHOR]

Background: The role of soil mesofauna in decomposition processes still is debated and this applies in particular to arable systems. Aim: This study investigates the role of Collembola in decomposition processes of crop residues in two different tillage systems. Methods: We conducted a litterbag experiment in a long‐term field site in Germany managed by conventional tillage (CT; mouldboard ploughing) and minimum tillage (MT). Litterbags filled with maize leaf litter of two mesh sizes (2 mm and 48 μm) were used. Litterbags were buried at 23 cm (CT) and 5–8 cm (MT), and retrieved after 2, 5 and 7 months. Litter mass, concentrations of carbon and nitrogen, litter C/N ratio as well as the abundance and community structure of Collembola and the incorporation of maize‐derived carbon into Collembola were investigated. Results: Mesofauna enhanced the loss of litter carbon, while litter mass loss was reduced. Litter C/N ratio in MT was generally lower than that in CT and decreased faster in litterbags with coarse mesh size. Abundance of Collembola in litterbags in CT exceeded that in MT, but species composition remained unaffected by tillage. Overall, Collembola effectively colonised the litter irrespective of tillage system, but benefited in particular from translocation deeper into the soil by conventional tillage. Conclusions: Mesofauna accelerates litter carbon loss and increases litter nitrogen accumulation irrespective of tillage system. This may reduce nitrogen losses due to leaching in winter and facilitate nitrogen capture from decomposing litter material by crops in the following season, thereby contributing to the sustainable management of arable systems. [ABSTRACT FROM AUTHOR]

Abstract: Chisel plough or no-till practises are clearly attributed to sustainable farming for the support of soil organisms and soil biological functioning. However, in organic farming these techniques are only applied to a very small extent since there is a need for cultivation to control weeds. In organic farming it is important to develop and establish less destructive soil tillage practises to benefit from the support of soil organisms, especially from ecosystem engineers like earthworms. In this study three tillage systems were compared on a silty, loess'' derived soil in a 6 crop rotation. The tillage systems established were: (1) “ecomat” shallow (10cm) inversive ploughing; (2) a ridge culture system; and (3) conventional tillage (inversion tillage) down to 30cm. In fall 2005, three years after establishment of the field plots earthworm communities were investigated using formalin extraction. In total 6 species were detected. The earthworm abundance was low, ranging from 0 to 84 individuals m−2. Shallow ploughing using the “ecomat” technique was not different than conventional ploughing in its effects on earthworm populations, while the ridge culture system was significantly reduced in earthworm numbers and biomass compared to conventional ploughing. We conclude that both “ecomat” and “ridge culture” do not support earthworms and significantly reduce earthworm densities. The reductions in tillage depth alone are not effective for improving the habitat quality for earthworms in soil. [Copyright &y& Elsevier]

It is widely known that annelids have strong soil functional impacts like the decomposition of crop residues, which affects carbon dynamics and nutrient cycling. In this study the objective was to investigate the combined effect of the vertical placement of organic material and soil annelids on carbon pathway and plant available nutrients. We hypothesize that endogeic earthworms, such as anecic earthworms and thus enchytraeids react differently because of their various lifestyles. A microcosm experiment with undisturbed soil columns (30 cm high, 15 cm Ø) was carried out from October 2017 to February 2018 in a dark climate chamber at 10 °C. The soil columns were taken from a long-term experimental field-site at plots with reduced tillage after winter wheat harvest. The soil type is a Haplic Luvisol with a silt loam texture. Soil columns were defaunated by freezing for one week at -20°C before the experiment started. During the experiment they were hermetically sealed, continuously supplied with fresh air and automatically irrigated (3 times day-1 10 ml). Gas fluxes were obtained and analyzed every 4.5 hours utilizing a gas chromatograph. For the organism treatment we used: (i) the endogeic earthworm species Octolasion cyaneum (four individuals each column), (ii) the anecic earthworm species Lumbricus terrestris (two individuals each column) or (iii) a combination of the two enchytraeid species Enchytraeus crypticus and E. christenseni (350 individuals each column). Half of the columns were inverted manually to simulate inverse tillage. For these columns we placed 5 g of maize leaves, which was used as a crop residue, in a depth of 15 cm. For the columns with simulation of no-till systems, the organic material was put on the surface. All annelid treatments were combined with both organic matter location treatments.At the end of the experiment, soil columns were harvested destructively. Carbon-dioxide was measured as an indicator of biological activity [mg CO2-C kg-1 dry soil]. For biotic soil properties mircrobial biomass carbon was measured by Chloroform-Fumigation-Extraction (CFE) and ergosterol concentration was quantified as a proxy for fungal biomass. The path of carbon through the system is investigated by isotope ratio mass spectometry 13C/12C. First results show that earthworms reached a higher biomass in all treatments and numbers of enchytraeid individuals increased ten times. Contrary to the expectation that anecic earthworms only pick up organic matter, which is on the surface, the uptake of maize leaves could be shown by isotopic analysis in both treatments. On the other hand, it could be confirmed that the position of organic material in a depth of 15 cm seems to be of advantage for endogeic earthworms. Analysis of the biological activity shows that soil annelids respond in a different way the location of the organic material, depending on size scales (enchytraids vs. earthworms) and on ecological performance (endogeic vs. anecic earthworms). [ABSTRACT FROM AUTHOR]