During environmental migration, large plastic fragments can undergo degradation into microplastics (MPs), posing a significant threat to ecosystems. A research gap exists in understanding how MPs age in complex environments. We modeled aging by integrating an aging index with degradation kinetics. This study investigated the degradation of MPs (polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC)) exposed to ultraviolet radiation in seawater. Aged MPs exhibited cracks, oxidized particles, and wrinkles on their surfaces. The functional groups experienced stretching (e.g., -OH, C-H, C=O) and bending (e.g., X-H in-plane, C-H in-plane), as identified through Fourier transform infrared spectroscopy (FTIR). Meanwhile, the crystallinity of MPs increased initially but decreased over time. The roughness and carbonyl index (CI) of MPs was increased as the weathering time progressed. mPE and mPP exhibited the most pronounced aging. The Elovich kinetic model poorly fitted the CI for aged MPs. A First-order kinetic improvement model fitted well but lacked clear parameter significance. The degradation mechanisms of mPE and mPP were similar. The benzene ring structure in mPS and dechlorination experienced by mPVC render them resistant to degradation. This study provides evidence that that enhances our understanding of the mechanisms underlying the aging process of MPs in seawater.

Wood vinegar, a by-product of charcoal biomass pyrolysis, has been used as a biofungicide in plant disease management because of its antimicrobial properties. However, the physiological and biochemical mechanisms through which wood vinegar alleviates biotic stress are poorly understood. In this study, pot experiments were conducted to investigate the resistance and regulation mechanism of wood vinegar prepared from different raw materials (ZM) and from a single raw material (SM) in controlling tomato (Solanum lycopersicum “Bonny Best”) Fusarium wilt at different concentrations (0.3%, 0.6%, 0.9%, 1.2%, and 1.5%). The results showed that ZM and SM had significant control effects on tomato fusarium wilt under different concentrations in the same growth cycle. Under biotic stress, the two kinds of wood vinegar significantly increased the plant height, stem diameter, leaf area and yield of tomato under the concentration of 0.3%, 0.6%, 0.9% and 1.2%, and significantly reduced the content of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in tomato leaves. The effect of 0.9% treatment was the most significant, ZM and SM significantly increased tomato yield by 122% and 74%, respectively, compared with CK under 0.9% treatment. However, the plant height, stem diameter and leaf area of tomato were significantly reduced under 1.5% treatment, but the content of soluble sugar, soluble protein and vitamin C in tomato fruit was the best. Compared with CK, ZM significantly increased by 14%, 193% and 67%, respectively, and SM significantly increased by 28%, 300% and 159%, respectively. Except for 0.3% treatment, both significantly increased the activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) in tomato leaves. The response intensity of two kinds of wood vinegar—physiological and biochemical—to tomato disease resistance, growth and development, showed ZM > SM. The disease index of tomato showed highly significant negative correlation with plant height, stem thickness, leaf area and antioxidant physiology CAT, and highly significant positive correlation with MDA and H₂O₂ content. In conclusion, ZM was more effective than SM in enhancing tomato disease resistance by promoting tomato growth and development, decreasing leaf MDA and H₂O₂ content, and inducing antioxidant enzyme activity in leaves at moderate concentrations.

Arbuscular mycorrhizal fungi (AMF) play key roles in enhancing plant tolerance to heavy metals, and iron (Fe) compounds can reduce the bioavailability of arsenic (As) in soil, thereby alleviating As toxicity. However, there have been limited studies of the synergistic antioxidant mechanisms of AMF (Funneliformis mosseae) and Fe compounds in the alleviation of As toxicity on leaves of maize (Zea mays L.) with low and moderate As contamination. In this study, a pot experiment was conducted with different concentrations of As (0, 25, 50 mgꞏkg⁻¹) and Fe (0, 50 mgꞏkg⁻¹) and AMF treatments. Results showed that under low and moderate As concentrations (As25 and As50), the co-inoculation of AMF and Fe compound significantly increased the biomass of maize stems and roots, phosphorus (P) concentration, and P-to-As uptake ratio. Moreover, the co-inoculation of AMF and Fe compound addition significantly reduced the As concentration in stem and root, malondialdehyde (MDA) content in leaf, and soluble protein and non-protein thiol (NPT) contents in leaf of maize under As25 and As50 treatments. In addition, co-inoculation with AMF and Fe compound addition significantly increased the activities of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) in the leaves of maize under As25 treatment. Correlation analysis showed that stem biomass and leaf MDA content were very significantly negatively correlated with stem As content, respectively. In conclusion, the results indicated that the co-inoculation of AMF and Fe compound addition can inhibit As uptake and promote P uptake by maize under low and moderate As contamination, thereby mitigating the lipid peroxidation on maize leaves and reducing As toxicity by enhancing the activities of antioxidant enzymes under low As contamination. These findings provide a theoretical basis for the application of AMF and Fe compounds in the restoration of cropland soil contaminated with low and moderate As.

Wood vinegar is a high-value acidic byproduct of biomass pyrolysis used for charcoal production. It is widely used in agriculture and forestry. The adverse effects of synthetic fungicides on the environment and human health have prompted the increasing use of biofungicides as alternatives to traditional products in integrated plant disease management programs. In recent years, there has been an increasing interest in the potential of wood vinegar as a disease management tool in agriculture and forestry. In this paper, the composition and preparation process of wood vinegar and its application in agriculture and forestry were introduced, and the effect and mechanism of wood vinegar against fungi, viruses and bacteria were summarized. The potential of wood vinegar as a sustainable and eco-friendly alternative to conventional chemical fungicides is also discussed. Finally, some suggestions on the application and development of wood vinegar were put forward.

The utilization rate of phosphogypsum (PG) is currently low, and prolonged storage poses environmental pollution. Therefore, there is an urgent need to promote resource-efficient utilization. This study investigated the alterations in the characteristics of modified PG artificial soil (MPG-soil) and their influence on buckwheat (Fagopyrum esculentum Moench) growth using hierarchical land reclamation technique (HLRT) and integrated land reclamation technique (ILRT). The results demonstrated that MPG-soil reduced bulk density (3.8–6.9%), enhanced moisture content (up to 22%), and improved enzymatic activity. HLRT achieved superior phosphorus mineralization (7.53 U/g S-NP activity) and increased buckwheat yield by 130.6% over controls. Despite elevated soil salinity, MPG amendments restricted heavy metal accumulation in grains (BCF < 0.3), though Pb levels exceeded national standards due to background contamination. Nutrient dynamics revealed increased phosphorus availability but reduced organic matter, necessitating supplemental fertilization. The Nemerow index confirmed all treatments as “Safe and Clean”, while principal component analysis highlighted HLRT’s efficacy in balancing soil structure and fertility. Proline accumulation in high-PG treatments indicated adaptive stress responses. MPG-soil effectively contained heavy metal migration, ensuring agricultural product safety. This study assessed the potential of PG for land reclamation, and provided guidelines for its safe utilization in agriculture.