It was hypothesized that seasonality and resource availability altered through tree girdling were major determinants of the phylogenetic composition of the archaeal and bacterial community in a temperate beech forest soil. During a 2-year field experiment, involving girdling of beech trees to intercept the transfer of easily available carbon (C) from the canopy to roots, members of the dominant phylogenetic microbial phyla residing in top soils under girdled versus untreated control trees were monitored at bimonthly intervals through 16S rRNA gene-based terminal restriction fragment length polymorphism profiling and quantitative PCR analysis. Effects on nitrifying and denitrifying groups were assessed by measuring the abundances of nirS and nosZ genes as well as bacterial and archaeal amoA genes. Seasonal dynamics displayed by key phylogenetic and nitrogen (N) cycling functional groups were found to be tightly coupled with seasonal alterations in labile C and N pools as well as with variation in soil temperature and soil moisture. In particular, archaea and acidobacteria were highly responsive to soil nutritional and soil climatic changes associated with seasonality, indicating their high metabolic versatility and capability to adapt to environmental changes. For these phyla, significant interrelations with soil chemical and microbial process data were found suggesting their potential, but poorly described contribution to nitrification or denitrification in temperate forest soils. In conclusion, our extensive approach allowed us to get novel insights into effects of seasonality and resource availability on the microbial community, in particular on hitherto poorly studied bacterial phyla and functional groups.

Phosphorus (P) is a vital mineral nutrient in agriculture and its deficiency results in reduced growth, yield, and grain quality in cereals. Much of the applied P in agriculture becomes fixed in soils, limiting its accessibility to plants. Thus, investigating sustainable strategies to release fixed P resources and enhance plant uptake is crucial. This study explored how plant-associated bacteria employ phosphate solubilizing mechanisms to improve P availability. The growth patterns of four bacterial strains, namely Bacillus subtilis ZE15 and ZR3, along with Bacillus megaterium ZE32 and ZR19, were examined in Pikovskaya’s broth culture with and without the addition of insoluble phosphorus (P). In the absence of P amendment, most strains reached a stationary growth phase by the fourth day. However, their responses diverged when exposed to P-amended media. Particularly, ZE15 demonstrated the highest P solubilization capability, achieving up to 130 µg mL⁻¹ solubilization in vitro. All strains produced organic acids in Pikovskaya’s broth culture. A comparison of the influence of Ca₃(PO₄)₂ revealed significantly greater organic acid quantities in the presence of insoluble P. Notably, strain ZE15 exhibited the highest phosphate esterase activity (3.65 nmol g⁻¹ dry matter), while strain ZE32 showed the highest ß-D glucosidase activity (2.81 nmol g⁻¹ dry matter) in the presence of insoluble P. The ability of Bacillus species to solubilize P in combination with increased exoenzyme activity in the rhizosphere could be used in future studies to support P uptake through enhanced solubilization and mineralization.

Compared to their annual analogues, perennial grain cropping systems provide various beneficial attributes for the environment and ecosystem services related to resource use efficiency, soil erosion, and soil conservation. However, there is only limited understanding of the multiple biotic interactions in perennial cropping systems and their potential effects on the crop, involving plant growth‐promoting and pathogenic microorganisms, beneficial and detrimental faunal organisms below‐ and above‐ground, weeds, and overall biodiversity effects. We use information from studies carried out in managed and natural perennial systems of analogous structure such as perennial energy crop production systems and grasslands to highlight and specify biotic interactions and processes, which potentially constitute advantages and constraints in developing perennial grain cropping systems. Concerning the relevance of soil microorganisms and potential perennial crop breeding goals, we focus on a range of plant–microbe interactions in the rhizosphere involved in biofertilization, phytostimulation, and biological control of soil pathogens. We consider relationships within the faunal community emphasizing arthropod pests and their natural enemies, as well as crop–weed interactions. Based on these outcomes and in comparison with annual systems, we discuss and compile benefits, options, and limitations of management of crop‐associated biotic interactions and biodiversity, which might contribute to reproducible and sustainable effects of perennial grain crop productivity. We conclude that management strategies for perennial grain cropping systems depend much more on ecological processes and interactions operating in natural ecosystems than those in annual cropping systems. Consequently, the use of agrochemicals for pest, weed, and disease control, as well as the use of synthetic fertilizers, counteracts the principle functions of the system and would strongly degrade the potential of biotic benefits. We also found that there is only vague information on the long‐term productivity and cultivation period of perennial grain crops, the specific management operations of replacement, and the potential development and management of weed and pest populations. Overall, an advanced understanding of interactions between the crop and its biotic environment provides the opportunity to manipulate specific functional traits of crop‐associated organisms for improved management and crop productivity, but significant research challenges for implementation of perennial grain crops still remain.

The pioneering plant Pueraria phaseoloides had a strong modulation effect on arbuscular mycorrhizal fungi (AMF) communities. Irrespective of geographical location, community composition of AMF in rhizosphere soil differed from that of the root. Co‐occurrence network analysis revealed two AMF keystone species in rhizosphere soil (Acaulospora) and roots (Rhizophagus) of P. phaseoloides.