Background: Irrigation with swine wastewater may increase the dissemination risk of antibiotic resistance genes (ARGs) in the rhizosphere and alter root exudate composition. However, the relationship between root exudates and ARG dynamics under swine wastewater irrigation remains poorly understood. This study therefore aimed to clarify how root exudates are connected with ARG dynamics under swine wastewater irrigation. Methods: To address this, untargeted metabolomics and metagenomic sequencing were combined to characterize rhizosphere ARG composition, microbial community structure, and root exudate profiles in different soybean cultivars under swine wastewater irrigation. Results: The results showed that irrigation water source and soybean cultivar were associated with variation in soil ARG composition and changes in plant root metabolic profiles. Under wastewater irrigation, the relative abundances of secondary metabolites in root exudates were generally elevated, particularly those of organic nitrogen compounds and organic oxygenated compounds. Cultivar-related variation remained evident in rhizosphere microbial communities and ARG profiles, and differences in exudate composition among cultivars became smaller. Irrigation water source and soybean cultivar were associated with changes in ARG dynamics. This association was mainly linked to variation in rhizosphere microbial community structure rather than direct effects of root exudates on ARGs. Xanthine and 3-isobutylpentanedioic acid, identified as key root exudates, increased under wastewater irrigation and were related to variation in the potential ARG host genus SCGC-AG-212-J23 and the related ARGs. In contrast, 5-methylheptan-3-one decreased under wastewater irrigation and was correlated with variation in SCGC-AG-212-J23, Gp6-AA40, and the related ARGs. Conclusions: Swine wastewater irrigation and soybean cultivar altered root metabolism, which were linked to variation in rhizosphere microbial communities. These changes may have collectively contributed to shifts in rhizosphere ARGs. This could provide a basis for understanding the ecological relationships among root exudates, microorganisms, and ARGs under swine wastewater irrigation.

The pollution of microplastics and antibiotics in aquaculture wastewater is a major concern, while current studies focus more on the removal of antibiotics than microplastics and their interaction effects on their removal. This review summarized the contamination and the remediation technologies of antibiotics and microplastics in aquaculture wastewater as well as their interaction effects on their removal during the remediation processes, and prospected the future development and challenges of current technologies. Microplastics can alter the migration and removal rate of antibiotics due to the adsorption of antibiotics, conversely, antibiotics may compete adsorption sites or reactive oxygen species with microplastics, the coexistence of microplastics and antibiotics may affect the hydrolysis and the biotoxicity of antibiotics and therefore their biodegradation, but how these interactions affect the behavior of microplastics is rarely examined. The combined remediation technologies considering the interaction between microplastics and antibiotics may be the direction of future efforts.

DETA-functionalized corn stalk cellulose (DCC) biosorbent was successfully prepared from corn stalks and applied to simultaneously remove Cu2 +, Pb2+ and Zn2+ from wastewater. Compared with raw corn stalk cellulose, DCC was rich in amino groups and was characterized with larger specific surface area as well as higher chemical polarity. Batch experiments were carried out to optimize the adsorption parameters including the pH value, contact time and initial concentration. The adsorption data followed the pseudo-second-order kinetics model and Langmuir isotherm model better, and the adsorption amount for Cu2+, Pb2+ and Zn2+ in ternary system were 59.10, 68.92 and 60.79 mg/g, respectively. FT-IR and XPS results revealed that the Ocontaining and N-containing groups on DCC surface played a prominent role in heavy metal adsorption by forming chelating complex with multiligand. Additionally, the DCC biosorbent presented good regeneration performance after 5 cycles. The findings in this paper revealed the DCC biosorbent had promising efficiency in heavy metal removal from effluents, and also offered an alternative strategy to recycle corn stalks for the purpose of 'waste treatment by waste'.

Straw return (SR) can affect the environmental behavior of pollutants. Currently, the impact of SR on the distribution and dynamics of soil antibiotic resistance genes (ARGs) remains inconclusive. Specially, the response of soil ARGs to the C/N ratio of straw returned to the soil has received scant attention. Here, a soil culture experiment was conducted to evaluate the impact of wheat straw return at varying C/N ratios adjusted with urea, and the ARG assembly and the probable propagators such as soil chemical properties, microbial community structure, mobile genetic elements (MGEs), and heavy metal resistance genes (MRGs) were analyzed. The results revealed that, after 60 days of incubation, C/N42 (only soil and straw) increased the absolute abundance of most ARG subtypes in the soil relative to CK (soil only), while C/N15 lowered the levels of soil ARGs, NH4+-N, NO3 --N, pH, and bioavailable Hg, and altered the soil microbial community structure. Compared with C/N42, the copy number of individual MRG and ARG subtypes in C/N15 decreased by 0.87 %-100 % and 20.33 %-100 %, respectively. Acidobacteria, Methylomirabilota, and Myxococcota, identified as potential host bacteria of ARGs, were associated with the removal of most ARGs. Chytridiomycota and Basidiomycota, potentially the primary fungi degrading straw, act synergistically with soil bacteria. Network and PLS-PM analysis across all treatments showed that soil MRGs and chemical properties accounted for more variance in ARG distribution than microbial communities and MGEs did. This study provides innovative insights into alleviating ARGs dissemination in farmland soil under the condition of SR.

The influence of soil water and temperature on soil respiration is often studied using incubation experiments due to the challenges associated with field measurements. While incubations preserve most chemical and biological properties of the soil, they alter the physical environment. A critical issue is whether these alterations make incubation results unrepresentative of those under field conditions. To address this gap, we developed a multiscale model to explicitly resolve key processes, which include heterogeneous microbial distribution and O2 dissolution and diffusion, controlling anaerobic CO2 production and microbial respiration of dissolved and gaseous O2 in the pore space. These processes are integrated into a macroscopic model to simulate CO2 emissions in soil profiles. We applied the model to published incubation and field experiments to evaluate its accuracy and ability to predict the moisture and temperature sensitivity of CO2 emissions. The model was then used to investigate how physical factors often overlooked in incubation experiments, such as soil depth, porosity and alteration of soil structure, impact the moisture and temperature response of CO2 emissions. Our results show that incubations substantially overestimate the temperature sensitivity of CO2 emissions compared to that under field conditions, due to changes in the physical environment. Modifying soil structure also alters the moisture and temperature response of CO2 emissions. These findings demonstrate the role of physical factors in regulating CO2 emissions and underscore the need for caution when extrapolating incubation results to field conditions or using them to predict the response of soil carbon dynamics to global warming.

While previous studies have suggested that biochar, nitrification inhibitors, and urease inhibitors may reduce soil greenhouse gas emissions, their effectiveness in soils irrigated with alternative water resources remains unclear. To compensate for this, reclaimed water and livestock wastewater were utilized as alternative water resources alongside groundwater control. Nitrapyrin and N-(n-butyl) thiophosphoric triamide and biochar were applied to the soil either individually or in combination, and a no-substance treatment (NS) was included for comparison. The results revealed that reclaimed water and livestock wastewater irrigation exacerbated the global warming potential. Compared to the NS, all exogenous substance treatments suppressed nitrous oxide (N2O) emissions while increasing carbon dioxide (CO2) emissions, and affecting methane (CH4) emissions varied across treatments irrespective of the water types. Interestingly, the additional biochar reduced the inhibitory effect of the inhibitors on the greenhouse effect. Using nitrification inhibitors reduced the global warming potential by 48.3% and 50.1% under reclaimed water and livestock wastewater irrigation, respectively. However, when nitrification inhibitors were applied in combination with biochar, the global warming potential was increased by 52.1–83.4% compared to nitrification inhibitors alone, and a similar trend was also observed in the scenario of urease inhibitors, with increases ranging from 8.8 to 35.1%. Therefore, the combined application of biochar and inhibitors should be approached cautiously, considering the potential for increased greenhouse gas emissions.

Understanding microbial diversity-function-stability relationships is essential for elucidating microbial ecological roles and environmental adaptability. However, the contribution of abundant taxa (AT) versus rara taxa (RT) to nutrient cycling and community stability remain unclear in peatland. In this study, we investigated six low-temperature peatlands in China to assess abundant and rare bacterial assemblages impact community stability. The AT and RT subcommunities in this study differed more in taxonomic composition than in functional potential, and AT dominated more carbon and nitrogen cycling, both of which were significantly affected by soil depth. Deterministic processes primarily governed both AT and RT community assembly (MST: AT: 0.257 vs. RT: 0.459), with their influence intensifying at greater depths. Notably, soil depth negatively affected the stability of the AT sub-community but had no significant impact on the RT stability. Surprisingly, higher Shannon diversity in both AT and RT was associated with reduced overall community stability, while changes in relative abundance of keystone taxa were a major driver of stability. Our results suggest that in nutrient-limited peatlands, changes in the abundance of key functional taxa—rather than diversity alone—play a dominant role in driving microbial stability. These findings highlight the critical role of abundant and rare taxa in maintaining peatland ecosystem function and resilience, emphasising their ecological significance in wetland sustainability.

Fertilization significantly influences the soil physicochemical properties and crop growth in agricultural ecosystems, yet our understanding of its impact on soil respiration remains limited. To bridge this knowledge gap, we conducted a comprehensive study in the winter wheat-summer maize rotation system of the North China Plain. We examined the driving factors and processes governing soil respiration, and its temperature sensitivity (Q10), in response to various fertilization treatments, including an unfertilized control (CK), organic fertilizer (OM), organic fertilizer in combination with mineral fertilizer (OMNPK), and mineral fertilizer (NPK). Our findings revealed significant changes in Q10 values under different treatments. In maize, Q10 values increased by 4.4 % in OM, 19.9 % in OMNPK, and 15.5 % in NPK treatments. Conversely, in wheat, Q10 values decreased by 9.9 %, 9.6 %, and 7.7 % under OM, OMNPK, and NPK treatments, respectively. Fertilization led to a substantial increase in mean soil respiration of both maize (6.6 %-12.7 %) and wheat (10.1 %-21.3 %). Moreover, fertilization significantly enhanced crop yield, stem biomass, and root biomass. In maize, soil respiration exhibited a linear increase with rising soil pH value, ammonium nitrogen and available potassium content, and crop biomass. Similarly, wheat soil respiration showed a linear trend with increasing soil pH value, total phosphorus, and soil organic carbon content. Structural equation modeling highlighted key factors contributing to variations in soil respiration. For maize, available potassium content, soil temperature, soil water content, and crop height explained 89 % of the variation. In wheat, pH value, total phosphorus, and total potassium content, soil temperature, soil water content, crop height, and crop biomass collectively accounted for 93 % of the variation of soil respiration. Fertilizer application significantly enhanced crop yield and carbon emission efficiency, specifically in wheat. Fertilized plots exhibited carbon emission efficiency 0.78-2.06 times higher than unfertilized plots in wheat. Among all treatments, OMNPK treatment maintained high yield, carbon emission efficiency, and net carbon sequestration in wheat. In summary, during winter wheat cultivation in the North China Plain, the practice of organic fertilizer combined with mineral fertilizer emerges as a superior strategy. This approach not only sustains crop yields but also augments carbon sequestration in crops, demonstrating its significant potential for agricultural carbon management.

Soil microbial communities are susceptible to perturbations by small mammalian herbivores, such as Brandt's voles (Lasiopodomys brandtii), through their foraging and burrowing behaviors. The interaction between these activities and climate change factors, particularly increased rainfall, can profoundly affect the structure and functions of soil microbial communities. However, the mechanisms by which soil microbial communities respond to small mammalian herbivores under climate change remain poorly understood. In this study, a 9-year manipulative experiment was conducted within a temperate steppe ecosystem to investigate these interactions under increased rainfall conditions. The results indicated that rainfall intensity modulated the impact of vole activity on soil microbial communities. The bacterial community showed an sensitivity to both vole activity and increased rainfall, whereas the fungal community remained relatively stable in terms of composition, functions and network. Vole activity resulted in a significant reduction in the diversity of the bacterial community, accompanied by alterations in its composition and network complexity. Light rainfall exacerbated the negative effects of voles on soil bacterial diversity, while moderate rainfall partially mitigated these impacts. Furthermore, our study found that the relative abundance of bacterial functional groups responded significantly to both vole activity and rainfall addition (P < 0.05). The changes of bacterial community composition were mainly attributed to shifts in the copiotrophic taxa Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. The direct effects of rainfall and vole activity were the primary pathways of soil bacterial diversity changes. Additionally, increased rainfall may reduce bacterial diversity indirectly by elevating soil pH. Overall, our study provides valuable insights into how burrowing rodents and climate change interact to disrupt grassland soil subsystems, highlighting the potential for climate change to modulate the ecological impacts of small mammalian herbivores.

Drought stress is one of the key factors restricting crop yield. The beneficial effects of exogenous proline on crop growth under drought stress have been demonstrated in maize, rice, and other crops. However, little is known about its effects on wheat under drought stress. Especially, the water-holding capacity of leaves were overlooked in most studies. Therefore, a barrel experiment was conducted with wheat at two drought levels (severe drought: 45% field capacity, mild drought: 60% field capacity), and three proline-spraying levels (0 mM, 25 mM, and 50 mM). Meanwhile, a control with no stress and no proline application was set. The anatomical features, water-holding capacity, antioxidant capacity, and proline content of flag leaves as well as grain yields were measured. The results showed that drought stress increased the activity of catalase and peroxidase and the content of proline in flag leaves, lessened the content of chlorophyll, deformed leaf veins, and decreased the grain yield. Exogenous proline could regulate the osmotic-regulation substance content, chlorophyll content, antioxidant enzyme activity, water-holding capacity, and tissue structure of wheat flag leaves under drought stress, ultimately alleviating the impact of drought stress on wheat yield. The application of proline (25 mM and 50 mM) increased the yield by 2.88% and 10.81% under mild drought and 33.90% and 52.88% under severe drought compared to wheat without proline spray, respectively.

Water resource shortage has become an important factor limiting agricultural sustainability in China. In addition, the development and utilization of unconventional water resources are greatly important for alleviating agricultural water resource deficit. The Pakchoi was cultivated by using the surface soil (0–20 cm) from the field in this pot experiment. The experiment lasted for approximately 1 month to study microbial community structure variation under brackish water and reclaimed water irrigation. The 16S rDNA high-throughput assays revealed that soil bacteria mainly consisted of Proteobacteria and Actinobacteria at the Phylum level, along with Arenimonas and Nocardioides at the Genus level under mixed irrigation with brackish water and reclaimed water. In summary, irrigation with pure reclaimed water promoted part of microbial communities and irrigation with pure brackish water inhibited the growth and activities of certain microbial communities. We found that mixed irrigation improved the microbial community structure diversity compared with that in response to pure brackish water irrigation, while decreased the community structure diversity compared with that in response to fresh water irrigation and pure reclaimed water irrigation.

【Background】Cadmium (Cd) is one of contaminants found in agricultural soils caused by anthropogenic activities including wastewater irrigation and application of phosphate fertilizers rich in Cd impurities, sludges and composts. In China, Cd contamination comes to the top in soils contaminated by all heavy metals and their metalloids. Since Cd is toxic to all organisms and highly mobile in soil for plants to take up, excessive Cd accumulation in crop tissues could impede its growth and even lead to mortality. Numerous studies showed that adding exogenous substances to soil could alleviate toxic effects of Cd on crops, but if and how their efficacy varies with crop variety remains poorly understood. 【Objective】Taking winter wheat as an example, this paper aimed to investigate the effects of exogenous Si, Ca, Mg and humic acid on uptake of Cd by different cultivars and its subsequent translocation at seedling stage. 【Method】Wheat varieties Bainong 419 (419) with high Cd accumulation in grain and Bainong 418 (418) with low Cd accumulation in grain were taken as the model plants. They were grown in hydroponic culture with the Cd content in it spiked to 10 mg/L or 30 mg/L respectively. We added Si, Ca, Mg and humic acid at different rates to the medium and harvested the crops 30 days later. We then measured Cd accumulation and transportation in roots and shoots, as well as root morphology traits. 【Result】Crop absorption of Cd varied with the wheat varieties, and the total length, surface area, volume and tip number of the roots in both varieties decreased with the increase in Cd concentration. Compared to variety 418, variety 419 took more Ca for its root developments. At low Cd concentration and compared to CK, adding Si at low dose improved root growth of the variety 419 and reduced Cd accumulation in its roots and shoots, while adding other elements inhibited root growth; applying humic acid at high dose enhanced Cd accumulation in the roots. It was found that compared to CK, adding any exogenous element reduced Ca content in the roots of the variety 419 when Cd concentration was low. For the variety 418 grown in medium with low Cd concentration, adding Si and Ca was more effective to promote root growth than adding Si alone, while adding Mg and humic acid did not show noticeable effects. Adding Si reduced Cd accumulation in roots and shoots at significant level, while adding Ca and Mg only impeded Cd accumulation in the root. Humic acid did not appear to have a noticeable impact on plant Cd. For the crops growing in medium with high Cd concentration, adding Si boosted root growth of both varieties regardless of its application rate, while in contrast, adding other elements were unable to alleviate Cd toxicity to plants at significant level. Compared with other treatments, adding Si at high does significantly increased the translocation factor (TF) for both varieties growing in medium with low Cd concentration, and it was also effective at boosting the TF for the variety 419 growing in medium with high Cd concentration. 【Conclusion】The most effective conditioner to alleviate Cd toxicity to winter wheat was Si, although its efficacy varies with wheat cultivar, Si application rate and Cd concentration in the medium where the crop grows.

To mitigate the issues of soil quality degradation and environmental pollution caused by excessive fertilizer use in apple orchards, the present study investigated the effects of organic fertilizer substitution combined with chemical nitrogen (N) fertilizer reduction on soil nutrient status, enzyme activity, and microbial communities (bacteria, fungi and archaea) over one year in an apple orchard. Five fertilization treatments were implemented, including 100% chemical fertilizer (CK), 80% chemical fertilizer + 20% liquid humic fertilizer (S1), 60% chemical fertilizer + 40% liquid humic fertilizer (S2), 60% chemical fertilizer + 20% liquid humic fertilizer (S3), and 40% chemical fertilizer + 40% liquid humic fertilizer (S4). Substituting chemical fertilizers with liquid humic fertilizers effectively enhanced the soil organic matter (SOM) content in the topsoil (0–20 cm) for all treatments. Compared to CK, the amounts of available N (NO3−-N and NH4+-N) were decreased in the topsoil and the amounts of total N, total phosphorous and available phosphorous were increased in the subsoil (20–40 cm) for all treatments. The β-diversity of bacterial communities exhibited the highest sensitivity to soil environmental changes, followed by that of archaea, whereas fungi demonstrated the least susceptibility. The higher soil carbon/nitrogen ratio and SOM content in S2 altered the abundance of microorganisms (Proteobacteria, Ascomycota, and Crenarchaeota) that were closely related to the decomposition and mineralization of SOM and N, enhancing the efficiency of SOM decomposition. The activities of sucrase (SUC), urease (UE), and phosphatase were increased, also promoting the conversion efficiency of SOM and improving N fixation and soil fertility. In the organic fertilizer substitution treatments (S1 and S2), the abundance of dominant Actinobacteriota, Ascomycota and Crenarchaeota phyla were increased, as well as the activities of SUC and UE, accelerating the decomposition and mineralization of SOM and improving soil fertility. In the top, organic fertilizer substitution combined with reduced chemical N fertilizer (S3 and S4) treatments increased the abundance of bacteria and fungi. In addition, RDA showed that total potassium content could significantly affect changes in the bacterial and fungal community structure in subsoil. Overall, organic fertilizer substitution enhanced the content of soil available nutrients and improved soil nutrient retention. It is recommended to promote organic fertilizer substitution + chemical N fertilizer reduction (S4) with the supplementation of potassium fertilizer in the subsoil. The findings provide a theoretical basis and practical guidance for improving orchard soil management and achieving sustainable development in the apple industry.

Water scarcity is a major challenge facing agricultural production in China. Unconventional water resources such as reclaimed wastewater can be used as a complimentary resource for irrigation. However, reclaimed wastewater is rich in salt and its long-term use for irrigation could lead to secondary soil salinization. In this review, we analyze the factors that have potential effects on accumulation of salt in soil. They include irrigation method, soil texture, crop types and crop variety, irrigation time, and reclaimed wastewater modification. Results show that our current understanding of the effect of long-term reclaimed water irrigation on soil salt accumulation is still unclear. As a result, more systematic studies are needed to elucidate the main factors that affect salt accumulation in soil. While reclaimed water modification is promising, more studies are required before it can be widely implemented. We suggest that future research on reclaimed water irrigation should focus on field experiments to systematically study how irrigation method, soil texture, crops, agronomic management and reclaimed water modification interactively affect salt accumulation in soils irrigated with reclaimed wastewater.

Treated livestock wastewater reuse for irrigation and straw return in arid regions have become common practices worldwide. However, many uncertainties still exist regarding the effects of the returning straw sizes on heavy metal accumulation in soil and plants under treated livestock wastewater irrigation. In a pot experiment growing maize and soybean, large (5–10 cm), medium (1–5 cm), and small (<1 cm) sizes of wheat straw were amended to assess the changes in Cu and Zn distribution in the rhizosphere, bulk soils, and plants. Groundwater and swine wastewater were used as irrigation water resources. The results showed that irrigation with swine wastewater significantly reduced soil pH and increased the concentration of soil-available potassium. Concentrations of Cu in soil were more sensitive to swine wastewater and straw application than those of Zn in soil. Swine wastewater irrigation increased the accumulation of Cu and Zn in plants with higher concentrations of Zn, while straw return tended to inhibit this increase, especially when a small size of straw was employed. In addition to providing a reference for revealing the interaction mechanism between swine wastewater irrigation and straw return, this study proposes feasible solutions to improve the efficiency of agricultural waste recycling and realize sustainable agricultural development.

Plant–soil feedback (PSF) and straw incorporation improve soil health and enhance plant growth. However, these systems underlying methods and ideas have separately evolved to a larger extent. The purpose of this study was to analyze the impacts of PSF combined with straw incorporation and intercropping on heavy metal (HM) migration in soil-plant systems, heavy metal resistance genes (HMRGs) abundance, and soil bacterial community composition under livestock wastewater irrigation. A two-phase experiment integrating PSF and straw returning was carried out using monocropped and intercropped maize/soybean irrigated with groundwater and treated wastewater. The results indicate that PSF combined with straw incorporation increases HM mobility with more pronounced effects under intercropping system. No potential health risk was recorded considering HM movement in soil-plant system with its content in soil and grains under permissible limits. This study showed that PSF increases soil bacterial composition and the HMRGs’ relative abundance while decreasing the relative abundance of antibiotic resistance genes (ARGs) under straw incorporation. In summary, PSF combined with straw incorporation under maize/soybean intercropping system is a suitable method to achieve safe production while reducing HM accumulation in soil and plant in treated livestock wastewater irrigation.

1. Droughts can affect ecosystem CO2 fluxes directly or indirectly by changing plant community composition. However, it is unknown whether shifts in plant community composition buffer or amplify the response of ecosystem CO2 fluxes to droughts with different seasonal timing, as plant phenology and physiology of the different plant functional types respond differently to droughts. 2. To identify the interaction of drought timing and plant community composition in regulating ecosystem CO2 fluxes, we conducted a three-year manipulative experiment in which extreme droughts occurring in the early, mid and late growing seasons were separately imposed on experimental plot communities comprising graminoids, shrubs and their combination in a semi-arid grassland of Inner Mongolia, China. 3. Overall, mid-season drought caused the largest negative effects regardless of plant community composition. In addition to decreasing aboveground biomass, mid-season drought suppressed fluxes by reducing leaf photosynthetic rate, while early-season and late-season drought reduced fluxes mainly by shortening growing season length. All three community compositions had consistent responses to early-season and mid-season droughts. However, ecosystem CO2 fluxes in the combination community were less negatively affected by late-season drought than in either shrub or graminoid communities because the growing season length was shortened less. 4. Synthesis. Our results highlight that it is important to account for interactions of seasonal timing and plant community composition when predicting magnitude and pathways of drought effects on ecosystem carbon cycling.

Livestock grazing may affect small mammalian herbivore-soil microbe interactions and their association with the structure and functions of the ecosystem. However, the role of factors such as vegetation and soil nutrients in regulating these impacts is not clear. Here we conducted a 9-year experiment in temperate steppe to study how Brandt’s vole (Lasiopodomys brandtii) affects the soil microbial community under different livestock grazing intensities. This experiment contained 12 field enclosures with three livestock grazing intensities: control (CK), light grazing (LG), and moderate grazing (MG). We found that vole activity does not significantly change soil microbial diversity under non-grazing conditions. However, under livestock grazing conditions, vole activity led to a significant reduction in soil bacterial diversity and an increase in fungal diversity, demonstrating the impacts of livestock grazing on rodents-soil microbe interactions. The activity of voles significantly altered soil bacterial community composition, with changes primarily attributed to variations in the relative abundance of the phyla Actinobacteria, Bacteroidetes, Firmicutes, Gemmatimonadetes, and Proteobacteria. The soil fungal community remained relatively stable despite vole activity, which can be attributed to the richness of fungal colonies in mycelium and their low sensitivity to changes in external conditions. Vole activity also influenced soil microbial functional groups, and the variations in these groups were further amplified by livestock grazing. Furthermore, the shift in the microbial community composition and diversity induced by vole activity were mainly associated with the reduction of plant aboveground biomass. Overall, our study suggested that livestock grazing enhanced the changes in the soil microbial community induced by rodents, underscoring the importance of managing livestock grazing regimes for grassland conservation.

The deep migration of soil nitrogen (N) poses a significant risk of N leaching, contributing to non-point-source pollution. This study examines the influence of microbial networks on the deep migration of chemical fertilizer N under varying irrigation management and multiple N fertilizer sources. A soil column experiment with eight treatments was conducted, utilizing 15N isotope labeling and metagenomic sequencing technology. The findings revealed that reduced irrigation significantly curbs the deep migration of chemical fertilizer N, and straw returning also mitigates this migration under conventional irrigation. Microbial network complexity and stability were markedly higher under reduced irrigation compared to conventional practices. Notably, network node count, average degree, and modularity exhibited significant negative correlations with the deep migration of chemical fertilizer N. The network topology indices, including node count, average clustering coefficient, average degree, modularity, and edge count, were found to be relatively more important for the deep migration of chemical fertilizer N. In conclusion, microbial networks play an important role in reducing the deep migration of chemical fertilizer N.

Soil contamination by Cd has drawn global attention, while how irrigation waters modulate Cd sorption and mobility in soil remains obscure. We address this by investigating how cropped sandy soil irrigated with different waters altered Cd sorption and mobility using a rhizobox experiment followed by a batch experiment. Maize were planted in the rhizoboxes and irrigated by reclaimed water (RW), livestock wastewater (LW) and deionized water (CK), respectively. The bulk soil sampled from each treatment after 60 days of growth was employed to measure the Cd sorption and mobility using the isothermal adsorption and desorption experiments. The results showed that, in a small rhizobox experiment, the adsorption rate of Cd by the bulk soil in the adsorption phase was much faster than the desorption rate in desorption phase. Irrigation with RW and LW both reduced the Cd adsorption capacity of soil, and the reducing degree brought by LW was more obvious. Cd desorption rate was very low but keep increasing in the desorption stage, and pre-RW irrigation had the potential to increase Cd desorption from soil. Although the results were obtained based on the bulk soil sampled from a rhizobox experiment, our study strongly suggests that the altered Cd adsorption and desorption behavior in the soil caused by the RW and LW irrigation may risk the farmland ecosystem and deserve more concern.