UNLABELLED: Growing catch crops can improve soil health by enhancing microbial diversity, but their impact may be constrained by how they are managed. This study examined the effects of different catch crop species and soil cultivation methods on bacterial and fungal diversity, and total soil microbial biomass. A 3-year field experiment on Luvi-haplic Chernozem included two catch crop species and five mixtures (further catch crop species) and three cultivation methods (ploughing, reduced tillage and no tillage), resulting in 21 treatments (7 catch crop species x 3 soil cultivations). Soil samples (0–15 cm depth) were collected annually in autumn and spring since 2021 to 2024. Microbial biomass was assessed using the chloroform fumigation extraction method, while fungal and bacterial diversity was analysed by amplifying and sequencing the ITS2 region of rDNA and the V4 region of the 16 S rRNA gene for fungi and bacteria, respectively, via Illumina paired-end amplicon sequencing. Soil cultivation methods affected bacterial diversity, with reduced tillage showing higher diversity and evenness than ploughing, though neither differed from no-till. However, no effect was observed on fungal diversity, including AM fungi, or microbial biomass. Catch crop species did not significantly impact microbial diversity or biomass. Neither cultivation method nor catch crop species influenced the ratios of functional trophic groups, such as pathogens, saprotrophs or symbionts. This study underscores the critical role of soil management practices—especially reduced tillage—in promoting soil health, primarily through the enhancement of bacterial diversity. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1038/s41598-025-15255-7.

• Keywords
• Fungal and bacterial diversity, Microbial biomass, No-tillage, Ploughing, Reduced tillage, Trophic groups of microorganisms,
• Publication type
• Journal Article MeSH

INTRODUCTION: Revegetation of barren substrates is often determined by the composition and distance of the nearest plant community, serving as a source of colonizing propagules. Whether such dispersal effect can be observed during the development of soil microbial communities, is not clear. In this study, we aimed to elucidate which factors structure plant and soil bacterial and fungal communities during primary succession on a limestone quarry spoil heap, focusing on the effect of distance to the adjoining xerophilous grassland. METHODS: We established a grid of 35 plots covering three successional stages - initial barren substrate, early successional community and late successional grassland ecosystem, the latter serving as the primary source of soil colonization. On these plots, we performed vegetation surveys of plant community composition and collected soil cores to analyze soil chemical properties and bacterial and fungal community composition. RESULTS: The composition of early successional plant community was significantly affected by the proximity of the source late successional community, however, the effect weakened when the distance exceeded 20 m. Early successional microbial communities were structured mainly by the local plant community composition and soil chemical properties, with minimal contribution of the source community proximity. DISCUSSION: These results show that on small spatial scales, species migration is an important determinant of plant community composition during primary succession while the establishment of soil microbial communities is not limited by dispersal and is primarily driven by local biotic and abiotic conditions.

• Keywords
• primary succession, soil bacterial community, soil fungal community, source habitat proximity, temperate grassland,
• Publication type
• Journal Article MeSH

BACKGROUND: Below-ground microbes mediate key ecosystem processes and play a vital role in plant nutrition and health. Understanding the composition of the belowground microbiome is therefore important for maintaining ecosystem stability. The structure of the belowground microbiome is largely determined by individual plants, but it is not clear how far their influence extends and, conversely, what the influence of other plants growing nearby is. RESULTS: To determine the extent to which a focal host plant influences its soil and root microbiome when growing in a diverse community, we sampled the belowground bacterial and fungal communities of three plant species across a primary successional grassland sequence. The magnitude of the host effect on its belowground microbiome varied among microbial groups, soil and root habitats, and successional stages characterized by different levels of diversity of plant neighbours. Soil microbial communities were most strongly structured by sampling site and showed significant spatial patterns that were partially driven by soil chemistry. The influence of focal plant on soil microbiome was low but tended to increase with succession and increasing plant diversity. In contrast, root communities, particularly bacterial, were strongly structured by the focal plant species. Importantly, we also detected a significant effect of neighbouring plant community composition on bacteria and fungi associating with roots of the focal plants. The host influence on root microbiome varied across the successional grassland sequence and was highest in the most diverse site. CONCLUSIONS: Our results show that in a species rich natural grassland, focal plant influence on the belowground microbiome depends on environmental context and is modulated by surrounding plant community. The influence of plant neighbours is particularly pronounced in root communities which may have multiple consequences for plant community productivity and stability, stressing the importance of plant diversity for ecosystem functioning.

• Publication type
• Journal Article MeSH