Integrated microbiome and multi-omics analysis reveal the molecular mechanisms of Eisenia fetida in response to biochar-derived dissolved and particulate matters

The interaction between biochar and earthworms: Revealing the potential ecological risks of biochar application and the feasibility of their co-application

Biochar's interaction with soil-dwelling organisms, particularly earthworms, is crucial in ensuring the effective and secure utilization of biochar in the soil. This review introduces the application of biochar in soil, summarizes how earthworms respond to biochar-amended soil and the underlying factors that can influence their response, discusses the synergistic and antagonistic impacts of earthworm activity on the efficacy of biochar, and considers the feasibility of applying them together. A review of existing research has identified uncertainty in the effect of biochar exposure on earthworms, with biochar derived from animal wastes, produced at higher pyrolysis temperatures, and used at higher doses of biochar having more negative effects on earthworms. Habitat modification, toxicity release, particle effects, and contaminant immobilization are underlying factors in how biochar affects earthworm indicators. While biochar in contaminated soils may alleviate the stress of pollutants on earthworms by decreasing their bioaccumulation, this remedial effect is not always effective. Additionally, earthworm bioturbation can enhance the migration, fragmentation, and oxidation of biochar, while also stimulating extracellular enzymes that convert biochar into 'vermichar'. Earthworms and biochar can synergize well to improve soil fertility and remediate soil organic pollution, yet exhibit contrasting roles in soil C sequestration and immobilizing heavy metals in soil. These findings highlight both the advantages and risks of their co-application. Therefore, when considering the use of biochar alone or with earthworms, it is crucial to thoroughly assess its potential ecotoxicity on earthworms and other soil organisms, as well as the influence of bioturbation, such as that caused by earthworms, on the effectiveness of biochar.

Co-exposure to boscalid and amoxicillin inhibited the degradation of boscalid and aggravated the threat to the earthworm

The extensive application of pesticides and antibiotics in agricultural production makes it possible for them to coexist in farmland, and the interaction of the two pollutants can lead to changes in environmental behavior and toxicity, creating uncertainty risks to soil and soil organisms. In this study, we explored the environmental behavior and the effects of earthworms under co-exposure to amoxicillin and boscalid and further explored the accumulation and toxic effects on earthworms. The results showed that amoxicillin increased the adsorption of boscalid in soil and inhibited its degradation. In addition, we noticed that the co-exposure of amoxicillin and boscalid caused intestinal barrier damage, which increased the bioaccumulation of earthworms for boscalid and led to more severe oxidative stress and metabolic disorders in earthworms. In summary, our findings indicate that amoxicillin can increase the ecological risk of boscalid in the environment and imply that the encounter between antibiotics and pesticides in the environment can amplify the toxic effects of pesticides, which provides new insights into the ecological risks of antibiotics.

Multi-omics reveals different impact patterns of conventional and biodegradable microplastics on the crop rhizosphere in a biofertilizer environment

Microplastics (MPs) from the incomplete degradation of agricultural mulch can stress the effectiveness of biofertilizers and ultimately affect the rhizosphere environment of crops. Yet, the involved mechanisms are poorly known and robust empirical data is generally lacking. Here, conventional polyethylene (PE) MPs and poly(butylene adipate-co-butylene terephthalate) (PBAT) / poly(lactic acid) (PLA) biodegradable MPs (PBAT-PLA BioMPs) were investigated to assess their potential impact on the rhizosphere environment of Brassica parachinensis in the presence of Bacillus amyloliquefaciens biofertilizer. The results revealed that both MPs caused different levels of inhibited crop both above- and belowground crop biomass (up to 50.11% and 57.09%, respectively), as well as a significant decrease in plant height (up to 48.63% and 25.95%, respectively), along with an imbalance of microbial communities. Transcriptomic analyses showed that PE MPs mainly affected root's vitamin metabolism, whereas PBAT-PLA BioMPs mainly interfered with the lipid's enrichment. Metabolomic analyses further indicated that PE MPs interfered with amino acid synthesis that involved in crops' oxidative stress, and that PBAT-PLA BioMPs mainly affected the pathways associated with root growth. Additionally, PBAT-PLA BioMPs had a bigger ecological negative impact than did PE MPs, as evidenced by more pronounced alterations in root antioxidant abilities, a higher count of identified differential metabolites, more robust interrelationships among rhizosphere parameters, and a more intricate pattern of impacts on rhizosphere metrics. This study highlights the MPs' impact on crop rhizosphere in a biofertilizer environment from a rhizosphere multi-omics perspective, and has theoretical implications for scientific application of biofertilizers.