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Acid rain and invasive plants have quintessential adverse impacts on terrestrial ecosystems. As an environmentally safe method for disposal of invasive plants, we tested the effect of biochar produced from these plants in altering soil deterioration under acid rain as compared with lime. Given the impacts of the feedstock type and soil properties on the response of soil to the added biochar, we hypothesized that the microbial community and functions would respond differently to the charred invasive plants under acid rain. A pot experiment was conducted to examine the response of soil microbiomes and functions to the biochar produced from Blackjack (Biden Pilosa), Wedelia (Wedelia trilobata), and Bitter vine (Mikania micrantha Kunth), or quicklime (CaO) at a rate of 1 % (w/w) under acid rain. Like soil pH, the nutrient contents (nitrogen, phosphorus, and potassium), calcium, and cation exchange capacity (CEC) were important as dominant edaphic factors affecting soil microbial community and functionality. In this respect, lime decreased nutrients availability, driven by 11-fold, 44 %, and 2-fold increments in calcium content, pH, and C/N ratio. Meanwhile, biochar improved nutrients availability under acid rain owing to maintaining a neutral pH (∼6.5), increasing calcium (by only 2-fold), and improving CEC, water repellency, and aggregation while decreasing the C/N ratio and aluminum content. Unlike biochar, lime decreased the relative abundance of Nitrosomonadaceae (the dominant ammonia-oxidizing bacteria) while augmenting the relative abundance of some fungal pathogens such as Spizellomycetaceae and Sporormiaceae. Given the highest nitrogen and dissolved organic carbon content than other biochar types, Wedelia-biochar resulted in the greatest relative abundance of Nitrosomonadaceae; thus, the microbial carbon and nitrogen biomasses were maximized. This study outlined the responses of the soil biogeochemical properties and the related microbial community structure and functionality to the biochar produced from invasive plants under acid rain. This study suggests that biochar can replace lime to ameliorate the effects of acid rain on soil physical, chemical and biological properties.

Growing evidence has suggested a strong link between gut microbiota and host fitness, yet our understanding of the assembly mechanisms governing gut microbiota remains limited. Here, we collected invasive and native freshwater snails coexisting at four independent sites in Guangdong, China. We used high-throughput sequencing to study the assembly processes of their gut microbiota. Our results revealed significant differences in the diversity and composition of gut microbiota between invasive and native snails. Specifically, the gut microbiota of invasive snails exhibited lower alpha diversity and fewer enriched bacteria, with a significant phylogenetic signal identified in the microbes that were enriched or depleted. Both the phylogenetic normalized stochasticity ratio (pNST) and the phylogenetic-bin-based null model analysis (iCAMP) showed that the assembly process of gut microbiota in invasive snails was more deterministic compared with that in native snails, primarily driven by homogeneous selection. The linear mixed-effects model revealed a significant negative correlation between deterministic processes (homogeneous selection) and alpha diversity of snail gut microbiota, especially where phylogenetic diversity explained the most variance. This indicates that homogeneous selection acts as a filter by the host for specific microbial lineages, constraining the diversity of gut microbiota in invasive freshwater snails. Overall, our study suggests that deterministic assembly-mediated lineage filtering is a potential mechanism for maintaining the diversity of gut microbiota in freshwater snails.

The incorporation of organic amendments is widely acknowledged for its capacity to enhance soil fertility and boost crop productivity. However, whether the addition of organic amendments can improve soil quality and crop production, simultaneously causing methane emissions in paddy fields, deserves further investigation. In this meta-analysis, the effects of different organic amendments on soil nutrient levels, rice yield and CH4 emissions were evaluated in paddy fields based on 328 observations from 77 field trial studies. Our results revealed that the addition of organic amendments significantly increased soil organic carbon (9.47%), microbial biomass carbon (21.13%), microbial biomass nitrogen (28.91%), urease (25.07%) and β-glucosidase (24.41%). Moreover, straw addition significantly increased the CH4 emissions by 152.68% and rice yield by 7.16%; green manure addition significantly increased CH4 emissions by 71.62% and rice yield by 10.09%, respectively. Although both increased the CH4 emissions, green manure had the ability to improve the availability of N, which could improve rice uptake. The regression results showed that the variation in crop yield, soil nutrients and CH4 emissions are influenced through the types and quality of organic amendments. Overall, this study suggests that organic amendments are beneficial in maintaining soil quality and improving rice yield, whereas it also increased the CH4 emissions. These meta-analysis results may provide some references for optimizing organic amendments incorporated into the soil to sustain soil fertility and crop production while mitigating soil constraints and methane emissions.

Understanding who adopt green production and why they choose this strategy is an important issue that needs to be addressed in the context of increasingly severe agricultural pollution. Previous studies have generally investigated subsistence-oriented smallholders, typically employing profit maximization or risk minimization models. However, Chinese farmers have differentiated, and have unique characteristics. This study collected data from 960 random samples of rice farmers and conducted quantitative analysis. The findings reveal that 94.9 % of the farmers had less than 2-ha rice-planting area, and 80.21 % of farmers reported that their purpose of planting rice was for family self-feeding. Furthermore, the new standard to define smallholder based on whether their production purpose is self-feeding or selling and found that non-smallholders had an overall advantage and passed the t-test. Even more non-smallholder (76.32 %) intentionally chose green pesticide than smallholders (66.1 %), but their decision-making logic was different. Binary logistic regression results show that three aspects of self-actualization (environmental, market, and personal) positively and significantly affected the green production behavior of smallholders, but not significant for non-smallholders. This study suggests that in China, where smallholders are the mainstay of agriculture production, green production by smallholders will greatly improve the ecological environment and provide high quality agricultural products.

Many forms of traditional raised bed systems could be found around the world. Several of them have been identified as Globally Important Agricultural Heritage Systems (GIAHS) sites by Food and Agriculture Organization of the United Nations. Unlike traditional raised bed systems with similar structures in the Americas, the high bed–low ditch (HBLD) system in tropical and subtropical Asia, which is originated and developed from rice production, has been playing an important role in enhancing food security and maintaining farmer livelihood for centuries. Moreover, products provided by HBLD system are not only important for the livelihood of the local farmers, but also important for people living in the nearby towns and cities especially for vegetable and fruit supply. In this system, the ditches or sunken beds can be used to lower the groundwater table, retain nutrients and soil particles washed from the bed, grow rice or aquatic vegetables, and raise fish or shrimp. The HBLD system can also help to reduce salinity in coastal lowlands due to the presence of ditches. The raised beds can be used to grow various upland crops. Compared with rice monocropping, the adoption of HBLD system significantly improves the cropping intensity, productivity, employment, and income of farmers. Famers’ long-term practices fully demonstrate that this system is a type of sustainable agriculture with strong adaptability to the changes of natural environment. However, it should also be noted that the large-scale development of HBLD systems is not simply dependent on natural conditions, but is also determined by specific socioeconomic factors, such as good transportation facilities, a well market system, and a sufficient supply of labor. As a model of equilibrium between food production and high levels of biodiversity maintenance, the HBLD system is an important agricultural heritage system with global significance, and it should be well preserved and utilized in new ways to realize its important multiple functions under conditions of rapid urbanization in lowland and coastal regions.

Abstract Pomacea canaliculata was by far one of the most harmful invasive organisms in the world, causing serious harm to aquatic crops and ecosystem. Calcium carbonate is a common component of aquatic environment, which is important for the growth of Pomacea canaliculata. Therefore, the objective of this study was to investigate the response characteristics of P. canaliculata suffered shell breakage to the addition of calcium carbonate in water environment. In this experiment, we explored the effects of calcium carbonate addition on the P. canaliculata shell repair rate, food intake, egg production, shell strength, and calcium content through breaking the snails shell and the addition of calcium carbonate treatment. The results showed that snail broken-shell repaired mostly within 21 days. The snails experienced a significant increase in shell repair rates during earlier days of the treatment, especially for female snails. Food intake of snails exhibited different patterns when their shells were broken and calcium carbonate was added. Shell breakage treatment combined with calcium carbonate addition significantly increased the diameter of snail eggs compared with the control and the calcium carbonate addition treatment without shell-broken snail group. There was no significant difference in shell strength or calcium content of male snails between the treatments. The study suggests that P. canaliculata exhibits a sex-dependent response pattern when subjected to shell damage and calcium carbonate addition. The findings can provide some references to better understand the invasion mechanism and survival strategy of the P. canaliculata.

Superhydrophobic surfaces have been used in various fields of engineering due to their resistance to corrosion and fouling and their ability to control fluid movement. Traditionally, superhydrophobic surfaces are fabricated via chemical methods of changing the surface energy or mechanical methods of controlling the surface topology. Many of the conventional mechanical methods use a top-to-bottom scheme to control the surface topolopy. Here, we develop a novel fabrication method of superhydrophobic substrates using a bottom-to-top scheme via polymer OSTE, which is a prototyping polymer material developed for the fabrication of microchips due to its superior photocuring ability, mechanical properties, and surface modification ability. We fabricate a superhydrophobic substrate by OSTE–OSTE micro mushroom forest via a two-step lithography process. At first, we fabricate an OSTE pillar forest as the mushroom stems; then, we fabricate the mushroom heads via backside lithography with diffused UV light. Such topology and surface properties of OSTE render these structures superhydrophobic, with water droplets reaching a contact angle of 152.9 ± 0.2°, a sliding angle of 4.1°, and a contact angle hysteresis of less than 0.5°. These characteristics indicate the promising potential of this substrate for superhydrophobic applications.

Global imperatives call for reduced water consumption in homogeneous, intensive farming systems, where farmland landscape heterogeneity significantly impacts anthropogenic, ecological, and socioeconomic factors. However, the impact of this heterogeneity on crop water footprint (WF) remains uncertain. To address this, this study assessed the WF at the landscape scale across 616 subplots (1 × 1 km) in a representative county of North China Plain from 2013 to 2019, integrating green (WFgreen), blue (WFblue), and gray (WFgray) water footprints. Results showed that the winter wheat–summer maize double cropping pattern (WM) exhibited the highest WFgreen, WFblue, and WFgray. Over six years, most subplots saw significant reductions in WFgreen, WFblue, WFgray, and WF. At the landscape scale, diversification (compositional heterogeneity), fragmentation, and spatial distribution (configurational heterogeneity) were assessed using Shannon’s diversity index (SHDI), edge density (ED), and effective mesh size (MESH), which exhibited average variations of 0.07, −3.16 m ha−1, and −5.86 m2, respectively. For WM patches, the percentage of landscape (PLAND) and MESH were used to evaluate diversification and spatial distribution, resulting in reductions of 1.14% and 2.32 m2, respectively. Regression analysis and structural equation modeling further illuminated the connections between the landscape pattern and WF, emphasizing the significant role of MESH in reducing WFblue and influencing crop diversity (p < 0.001). Therefore, spatial distribution, whether directly or through the mediation of diversification, demonstrated a more substantial overall impact on WF. Consequently, future research should prioritize investigating how spatial distribution influences crop choice and agronomic management in order to determine the optimal cropping patterns and field size that strike a balance between crop production and the water footprint. This study offers theoretical guidance and a scientific foundation for redesigning farmland landscapes to bolster water sustainability in intensive farming systems.

Abstract Rapid development in industrialization and urbanization causes serious environmental issues, of which acid rain is one of the quintessential hazards, negatively affecting soil ecology. Liming has been investigated for a long time as the most effective amendment to alter the adverse effects of soil acidity resulting from acid rain. Herein, this study tested the biochar produced from invasive plants as an alternative amendment and hypothesized that biochar can maintain better availability of macronutrients under acid rain than liming by improving soil chemical and biological properties. Therefore, a pot experiment was conducted to compare the effects of lime and biochar at two rates (1% and 3%) on soil available nitrogen (N), phosphorous (P) and potassium (K) under simulated acid rain of two pH levels (4.5: pH4.5 and 2.5: pH2.5) as compared with tap water (pH7.1) as a control treatment. Biochar was produced using different invasive plants, including Blackjack (Biden Pilosa), Wedelia (Wedelia trilobata) and Bitter Vine (Mikania micrantha Kunth). Liming decreased the availability of soil N, P, and K by 36.3% as compared with the control due to the great increment in soil pH and exchangeable calcium (Ca2+) by 59% and 16-fold, respectively. Moreover, liming reduced the alpha diversity of soil bacteria and fungi by 27% and 11%, respectively. In contrast, biochar at different types and rates resulted in a fourfold increment in the available N, P, and K as an average under acid rain (pH4.5 and pH2.5) owing to maintaining a neutral pH (6.5–7), which is the most favorable level for soil microbial and enzymatic activites, and the bioavailability of soil nutrients. Furthermore, biochar caused balanced increments in Ca2+ by threefold, cation exchange capacity by 45%, urease activity by 16%, and fungal diversity by 10%, while having a slight reduction in bacterial diversity by 2.5%. Based on the path, correlation, and principal component analyses, the exchangeable aluminum was a moderator for the reductions in macronutrients’ availability under acid rain, which decreased by 40% and 35% under liming and biochar, respectively. This study strongly recommended the use of biochar from invasive plants instead of lime for sustainable improvements in soil properties under acid rain. Graphical Abstract

Although pervasive microplastics (MPs) pollution in terrestrial ecosystems invites increasing global concern, impact of MPs on soil microbial community assembly and ecosystem multifunctionality received relatively little attention. Here, we manipulated a mesocosm experiment to investigate how polyethylene MPs (PE MPs; 0, 1%, and 5%, w/w) influence ecosystem functions including plant production, soil quality, microbial community diversity and assembly, enzyme activities in carbon (C), nitrogen (N) and phosphorus (P) cycling, and multifunctionality in the maize–soil continuum. Results showed that PE MPs exerted negligible effect on plant biomass (dry weight). The treatment of 5% PE MPs caused declines in the availability of soil water, C and P, whereas enhanced soil pH and C storage. The activity of C-cycling enzymes (α/β-1, 4-glucosidase and β-D-cellobiohydrolase) was promoted by 1% PE MPs, while that of β-1, 4-glucosidase was inhibited by 5% PE MPs. The 5% PE MPs reduced the activity of N-cycling enzymes (protease and urease), whereas increased that of the P-cycling enzyme (alkaline phosphatase). The 5% PE MPs shifted soil microbial community composition, and increased the number of specialist species, microbial community stability and networks resistance. Moreover, PE MPs altered microbial community assembly, with 5% treatment decreasing dispersal limitation proportion (from 13.66% to 9.96%). Overall, ecosystem multifunctionality was improved by 1% concentration, while reduced by 5% concentration of PE MPs. The activity of α/β-1, 4-glucosidase, urease and protease, and ammonium-N content were the most important predictors of ecosystem multifunctionality. These results underscore that PE MPs can alter soil microbial community assembly and ecosystem multifunctionality, and thus development and implementation of practicable solutions to control soil MPs pollution become increasingly imperative in sustainable agricultural production.

Abstract Soil microbial community composition plays a key role in the decomposition of organic matter, while the quality of exogenous organic matter (EOM: rice straw, roots and pig manure) can influence soil chemical and biological properties. However, the evidences of the effect of combination of crop residues and pig manure on the changes in soil microbial community and enzymes activities are scarce. A greenhouse pot experiment was conducted to investigate the potential effect of EOM by analyzing soil properties, enzyme activities and microbial communities. The experiment consisted of eight treatments: CK (control), S (1% (w/w) rice straw), R (1% (w/w) rice root), SR (1% (w/w) rice straw + 1% (w/w) rice root), and added 1% (w/w) pig manure to CK, S, R and SR, respectively. Results showed that the straw treatment significantly increased the microbial biomass (carbon and nitrogen) and total carbon and nitrogen contents, cellulase and β-1,4-glucosidase activities, bacteria (i.e., gram-positive bacteria and gram-negative bacteria) PLFAs contents relative to CK regardless of whether pig manure was added. Moreover, the interaction between crop residues (e.g., straw and roots) and pig manure significantly influenced the contents of microbial biomass nitrogen and microbial biomass phosphorus, and the ratio of gram-positive bacteria to gram-negative bacteria. Redundance analysis confirmed that pH, nitrate nitrogen, ammonium nitrogen and dissolve organic carbon contents were significantly associated with soil microbial community under crop residues without pig manure addition. Furthermore, the experiment results showed that pig manure application not only provided more abundant nutrients (C, N and P) but also induced higher microbial and enzymatic activity compared with no pig manure addition. Our findings suggest that the combination of above-ground straw and pig manure is a better option for improving the functions of soil ecosystem.

Rice is a staple food for nearly two-thirds of China’s population. As socio-economic development continues, there is a growing demand for high-quality rice. This study collected grain quality traits for 17,785 rice varieties approved throughout China, and categorized them into the following five types: indica inbred (II), indica hybrid (IH), japonica inbred (JI), japonica hybrid (JH), and indica-japonica hybrid (IJ). Comprehensive analyses were conducted to assess the differences and trends in rice quality across these varieties. We found that JI and JH excel in processing and cooking qualities, featuring higher brown rice and head milled rice rates, coupling with longer gel consistency. Inbred varieties display lower chalky rice rates than hybrids. Over several decades, head milled rice rates have notably increased across all types except for IJ. Transparency grade has decreased in nearly all types except for IJ, with similar declines observed in chalky rice rates and chalkiness degree, suggesting an overall progress in appearance quality. In terms of cooking and taste attributes, amylose content has decreased in most varieties except for IJ, and gel consistency has improved in indica varieties. Generally, the rice quality of varieties approved in China has shown a clear trend of improvement over the past 40 years. This study provides significant data support and theoretical backing for ongoing rice breeding efforts.

Pomacea canaliculata, as an invasive exotic species in Asia, can adversely affect crop yields, eco-environment, and human health. Application of molluscicides containing metaldehyde is one effective method for controlling P. canaliculata. In order to investigate the effects of metaldehyde on adult snails, we conducted acute toxicological experiments to investigate the changes in enzyme activities and histopathology after 24 h and 48 h of metaldehyde action. The results showed that the median lethal concentrations (LC) of metaldehyde on P. canaliculata were 3.792, 2.195, 1.833, and 1.706 mg/L at exposure times of 24, 48, 72, and 96 h, respectively. Treatment and time significantly affected acetylcholinesterase (AChE), glutathione S-transferase (GST), and total antioxidant capacity (TAC) activity, with sex significantly affecting AChE, GST, and TAC activity and time significantly affecting carboxylesterase (CarE). In addition, the interaction of treatment and time significantly affected the activity of GST, CarE and TAC. In addition, histopathological changes occurred in the digestive glands, gills and gastropods of apple snail exposed to metaldehyde. Histological examination of the digestive glands included atrophy of the digestive cells, widening of the hemolymph gap, and an increase in basophils. In treated snails, the hemolymph gap in the gills was widely dilated, the columnar cells were disorganized or even necrotic, and the columnar muscle cells in the ventral foot were loosely arranged and the muscle fibers reduced. The findings of this study can provide some references for controlling the toxicity mechanism of invasive species.

The earthworm, as a soil engineer, plays highly important roles in the soil ecosystem for shaping soil structure, promoting soil fertility, regulating microbial community composition and activities and decomposing soil pollutants. However, the research progresses on this important soil fauna have rarely been reviewed so far. Therefore, we conducted a bibliometric analysis of the literature published during 1900–2022, which was collected from the Web of Science Core Collection (WoS). The results showed that three periods (1900–1990, 1991–2005 and 2006–2022) could be identified in terms of the intensity of publications on the topic, and the number of publications kept increasing since 2006. The United States produced the highest publication record at the country scale, whereas Chinese Academy of Sciences was the most productive institution. Chinese institutions and authors played an active and prominent role during 2018–2022. Soil Biology & Biochemistry was the most popular journal for the topic-related research. In these publications, Professor Lavelle P was the most influential author. Based on a citation network of the top 50 cited papers, four hotspots were identified, i.e., the ecological effects of earthworms, the impact of agricultural activities on earthworms, earthworm ecotoxicology and earthworm invasion. Moreover, “impact”, “biodiversity”, “oxidative stress”, “diversity”, “response”, “Eisenia fetida” and “exposure” were the emerging and active topics in recent years. This study can help us to better understand the relevant subject categories, journals, countries, institutions, authors and articles and identify the research hotspots and emerging trends in the field of soil earthworm research.

Invasive plant species are often characterized by superior resource acquisition capabilities compared with native species, contributing to their success in new environments. However, the dominance of these species varies, and not all invasive species become dominant, nor are all native species uniformly vulnerable to competitive exclusion. In this study, we analyzed 19 functional traits across 144 herbaceous plant species in Guangzhou, China. The studied species included 31 invasive dominant species (IDS), 19 invasive non-dominant species (INS), 63 native dominant species (NDS), and 31 native non-dominant species (NNS). Our findings reveal no significant differences in functional traits between IDS and INS, indicating a broad trait similarity within invasive categories. Pronounced similarities between invasive species and NDS suggest an ecological equivalency that facilitates successful integration and competition in new habitats. Notable differences in several key traits—height, leaf thickness, leaf water content, stoichiometry, photosynthetic rate, water use efficiency, and nitrogen use efficiency—indicate a competitive superiority in resource acquisition and utilization for invasive species over NNS. These distinctions are vital for understanding the mechanisms driving the success of invasive species and are crucial for developing strategies to manage their impact on native ecosystems.

Being regarded as one of the environmental problems endangering biodiversity and ecosystem health, acid rain has attracted wide attention. Here, we studied the effects of nitric acid rain (NAR) on the structure and diversity of microbial communities in agricultural soils by laboratory incubation experiments and greenhouse experiments. Our results indicated that NAR had an inhibitory effect on soil microorganisms, showing a significant reduction in the Chao1 index and Shannon index of soil bacteria. Proteobacteria, Acidobacteriota, Actinobacteriota, and Chloroflexi were the dominant bacterial phyla under NAR stress in this study. NAR significantly reduced the relative abundance of Proteobacteria and Actinobacteria, but significantly increased the relative abundance of Acidobacteriota and Chloroflexi, suggesting that NAR was unfavorable to the survival of Proteobacteria, and Actinobacteria. It is worth noting that the inhibitory or promoting effect of NAR on the dominant bacterial phyla gradually increased with increasing NAR acidity and treatment time. In addition, the study observed that the change in soil pH caused by NAR was the main reason for the change in soil bacterial community structure. In summary, the effects of NAR on soil microorganisms cannot be underestimated from the perspective of sustainable agricultural development.

Recent studies have indicated that the invasive apple snail (Pomacea canaliculata) exhibits tolerance to the salinity levels present in coastal agricultural soils, suggesting that apple snails could potentially invade salt-affected coastal agricultural areas. However, the effects of the alien snail Pomacea canaliculata invasion on coastal saline soils, such as in terms of soil properties, microbial diversity, and abundance, remain poorly understood. To fill this gap, we conducted experiments involving three salinity levels (0, 2‰, and 5‰, w/w), coupled with varying snail densities (0, 5, and 10 snails per box), applied to agricultural soil. We analyzed soil chemical properties, enzyme activities, and bacterial communities. The findings revealed that heightened soil salinity increased soil electrical conductivity (EC) (exceeding 1312.67 μS cm−1). Under saline conditions, snail treatments significantly increased the soil organic matter (SOM) content from 15.82 mg kg−1 to 18.69 mg kg−1, and concurrently diminished the dissolved organic carbon (DOC) from 47.45 mg kg−1 to 34.60 mg kg−1. Both snail and salinity treatments resulted in ammonia nitrogen (NH4+-N) accumulation, while nitrate nitrogen (NO3−-N) concentrations remained low in salt-affected soils. A notable positive correlation existed between the EC and the activities of hydroxylamine reductase (HR) and peroxidase (POD), where HR exhibited a positive correlation with NH4+-N, and POD displayed a negative correlation with NO3−-N. Salinity substantially decreased the diversity and altered the composition of soil bacterial community, with the phyla Bacteroidota, Proteobacteria, and Firmicutes adapting to salt-affected soil environment and proliferating. Structural equation modeling (SEM) analysis indicated that snails exerted a direct influence on soil-available nitrogen (including NO3−-N and NH4+-N), while salinity impacted available nitrogen by modulating soil enzyme activities and bacterial communities. Our findings provide insights into how soil responds to the concurrent impacts of snail invasion and soil salinization, establishing some references for future research.

In today's society, citizens' ecological literacy (ecoliteracy) is critical for their understanding of sustainable development. This study used a questionnaire designed to quantitatively assess ecoliteracy from a linguistic ecology perspective. First, an underlying mechanism model for ecoliteracy was designed based on the results of previous studies. Then, the ecoliteracy level assessment scores of Guiyang inhabitants were combined with the respondents' corresponding lifestyle characteristics to explore the effectiveness of interventions in affecting the participants' ecoliteracy levels. The results showed that the formation and development of ecoliteracy is a dynamic and circular process that revolves around variables of independent, dependent, mediating, moderating and control. The various factors in the model interact and operate evenly along a particular path. As for the level of lifestyle characteristics, participants' ecoliteracy levels had a statistically significant relationship with their attitudes regarding the importance of nature, participating in outdoor activities, and improving their ecoliteracy levels; as well as the frequencies regarding daily outdoor activity, the main activities in ecological areas, participation in volunteer activities, and use of ecological knowledge. The respondents with the highest levels of ecoliteracy had the most positive attitudes and engaged in ecological actions with the highest frequency. The lifestyle intervention features here are of great significance to the harmonious coexistence between humans and the natural environment and are also helpful for improving human health.

Partial replacement of chemicals with biological fertilizers is a recommended strategy to reduce the adverse environmental effects of chemical fertilizer losses. Enhancing the reduced mineral with biological fertilizers strategy by foliar application of humic acid (HA) and amino acids (AA) can reduce environmental hazards, while improving maize (Zea mays L.) production under semiarid conditions. The recommended doses of N, P and K (e.g., 286 kg N ha-1, 75 kg P2O5 ha-1 and 67 kg K2O ha-1) were applied as the first fertilization level (100% NPK) and were replaced with biofertilizers by 100%, 75%, 50% and 25% as levels of reducing mineral fertilization. These treatments were applied under four foliar applications of tap water (TW), HA, AA and a mixture of HA and AA. Our results reported significant reductions in all parameters, including maize ear yield attributes and grain nutrient uptake, when replacing the mineral NPK with biofertilizers by 25-100% replacement. However, these reductions were mitigated significantly under the application of growth stimulants in the descending order: HA and AA mixture>AA>HA>TA. Applying a mixture of HA and AA with 75% NPK + biofertilizers increased ear length, grain yield, grain uptake of N and K, and crude protein yield by 37, 3, 4, 11 and 7%, respectively as compared with 100% mineral fertilizer only. Moreover, all investigated parameters were maximized under the application of 75% NPK + biofertilizers combined with AA or the mixture of HA and AA, which reveals the importance of growth stimulants in enhancing the reduced chemical NPK strategy. It could be concluded that the mineral NPK rate can be reduced by 25% with biofertilization without any yield losses when combined with HA and AA under arid and semi-arid conditions. That achieves the dual goals of sustainable agriculture by improving yield, while reducing environmental adverse effects.

The harm of microplastics (MPs) to aquatic ecosystems is caused by their stable and non-degradable properties. Additionally, the pollutants such as heavy metals in the water are easy to be adsorbed on their surface with their small particle size and large specific surface area, resulting in environmental pollution. Therefore, the study on the mixture toxicity of MPs and heavy metals has theoretical significance for the risk assessment of aquatic ecosystems. In the present study, 10 nm polystyrene (PS) and cadmium (Cd) were used, and their individual and mixture acute toxicities on grass carp (Ctenopharyngodon idellus) were examined. The results indicated that the mortality of the fish increased with the concentration from 10 mg L−1 to 20 mg L−1, and the existence of PS-MPs elevated the Cd concentrations in the fish and accelerated the death. Whether the Cd and/or the PS-MPs concentrations caused varying degrees of damage to the gills, kidney, liver, and muscles of the grass carp, especially under the highest concentrations (20 mg L−1 Cd + 300 μg L−1 PS-MPs). Moreover, low concentrations of PS-MPs alone (30 μg L−1 PS-MPs) significantly increased the superoxide dismutase (SOD) activity in the kidney and liver, reaching 12.43% and 14.38%, respectively (P

There have been few studies on the impact of nitrogen deposition on paddy field ecosystem; therefore, we evaluated the effects of different N deposition levels (0, 40, and 120 kg N·ha−1) with the conventional nitrogen rate (180 kg N·ha−1) on rice field ecosystem through two-season experiments. The results showed that 40 and 120 kg·ha−1 nitrogen deposition had no significant effect on rice yield, although the rice grains per panicle and the 1000-grain weight increased. The 40 and 120 kg·ha−1 nitrogen deposition levels had no significant effect on rice and soil total carbon/total nitrogen (TC/TN) in the two-season experiment; however, 40 and 120 kg·ha−1 nitrogen deposition significantly increased TP content of the rice root and soil in a short time, and continuous 120 kg·ha−1 nitrogen deposition significantly decreased TP content of the rice root and significantly increased TP content of the rice stem. In addition, nitrogen deposition significantly reduced total carbon/total phosphorus (TC/TP) and total nitrogen/total phosphorus (TN/TP) in the soil. The activities of soil acid phosphatase (S-ACP), β-glucosidase (S-β-GC), and N-acetyl-β-D-glucosidase (S-NAG) increased under 40 kg·ha−1 nitrogen deposition, while the activities of S-β-GC and S-NAG decreased under 120 kg·ha−1 nitrogen deposition compared with 40 kg·ha−1. The microbial carbon, microbial nitrogen, microbial phosphorus, and fungal microbial biomass reduced under 40 and 120 kg·ha−1 nitrogen deposition. These findings suggest that, under short-term N deposition, rice and soil can adjust the C, N, P, and even the nutrient balance by themselves; however, continuous nitrogen deposition may have adverse reactions to microorganisms, thereby disrupting this balance and ultimately leading to the deterioration of paddy soil environment and a reduction in rice yield in the long term.

Cropland reactive nitrogen losses (Nr) are of the greatest challenges facing sustainable agricultural intensification to meet the increases in food demand. The environmental impacts of Nr losses and their yield responses to the mitigation strategies were not completely evaluated. We assessed the environmental impacts of Nr losses in China and coupled the efficiency of mitigation actions with yield responses. Datasets about Nr losses in China were collected, converted into potentials of acidification (AP), global warming (GWP), and aquatic eutrophication (AEP), and analyzed by a meta-analysis program. Results showed that producing 1 Mg of rice grains had the highest AP (153 kg acid equiv.), while wheat had the highest GWP and AEP (74 kg CO2 equiv. and 0.37 kg PO4 equiv., respectively). Using the conventional rates (averagely, 200, 230, and 215 kg N ha−1) of urea as a surface application to produce 131.4, 257.2, and 212.1 Tg of wheat, maize, and rice resulted in 17–33 Tg, 7–10 Tg, and 6–87 Gg of AP, GWP, and AEP, respectively. For their balanced effect on reducing AP, GWP, and AEP while maximizing yields, inhibitors, and subsurface application could be set as the best mitigation strategies in wheat production. Inhibitors usage and biochar are strongly recommended strategies for sustainable production of maize. None of the investigated strategies had a balanced effect on rice yield and the environment, thus new mitigation technologies should be developed.

Apple snails (ASs), the freshwater snails of the family Ampullariidae, are widely spread in tropical and subtropical regions. Owing to their strong invasiveness and harmful effects on agricultural production and ecosystems, they have attracted considerable attention. However, less research has been conducted on the whole picture of the current research status and development trends in the ASs field. For this purpose, we conducted a bibliometric analysis based on a total of 1028 publications regarding ASs published between 1900 and 2021 using VOSviewer 1.6.18 and CiteSpace 6.1.R3 software. The results suggest that ASs research has received increasing attention in recent years. The most productive country has been the USA, while the institution with the most publications was Consejo Nacional de Investigaciones Científicas y Técnicas Conicet. “Zoology” was the category of the most popular subject, Journal of Molluscan Studies was the primary journal, and P.R. Martin was the most outstanding author in ASs field. Invasive alien species, alarm response, copper (Cu) exposure, taxonomy and phylogenetic analysis, Angiostrongylus cantonensis (parasite), control (including molluscicidal activity), growth and reproduction, and feeding preferences were the main research hotspots. Further, “Pomacea maculata”, “Evolution”, “Biology”, “Digestive gland”, “Phylogeny”, “Identification”, “Pomacea canaliculata caenogastropoda”, “Diversity”, and “Nonnative apple snail” have been emerging active topics in recent years. These findings can help researchers in this area to better understand the direction and advances of ASs research and are valuable for future research and agricultural practice of apple snail control.

As the frequency of droughts increases with climate change, the tolerance of aquatic organisms to abiotic stressors will become critical determinants of survival. Pomacea canaliculata has become a widely distributed agricultural and environmental pest in southern China. To evaluate their tolerance and adaptation under the drought condition, the survival, feeding, behavior, and antioxidant system changes in female and male P. canaliculata were investigated during drought stress and rewatering process through an indoor simulation experiment. The results showed that female snails laid eggs before burrowing into the soil to ensure offspring reproduction. Female P. canaliculata had higher survival rates than males under drought stress, and their recovery ability of activity after rewatering was also superior to those of males. The antioxidant system of P. canaliculata showed obvious activation with gender differences after rewatering. Overall, the survival rate of female P. canaliculata was higher after drought stress, and the resilience ability of female snails after rewatering was stronger, including in their behavior, feeding, and antioxidant system recovery. The P. canaliculata tolerance to drought and the ability to recover quickly after drought may contribute to their long-term survival and facilitate continuous invasion.

Pomacea canaliculata is native to South America and has become a widely distributed agricultural and environmental pest in southern China. Previous studies have primarily focused on the tolerance of P. canaliculata to various environmental factors, and compared non-native invasive P. canaliculata with natives or non-invasive congeners. However, there has been no research concentrated on variation in innate growth and reproductive characteristics between P. canaliculata in its native and invaded areas. To address this gap, we conducted the first comparison experiment between P. canaliculata from their native area (Argentina) and from an invaded area (China). We recorded the temporal dynamics of shell height of male and female P. canaliculata, and investigated the sexual maturation and egg-related indicators in two populations from each country, rearing them under homogeneous temperature, photoperiod and food conditions. Our results showed that the shell growth rate of P. canaliculata in Argentina was significantly lower than that of P. canaliculata in China. Moreover, P. canaliculata exhibited stronger reproductive characteristics in populations from China, mainly reflected in the earlier sexual maturity, larger egg masses, higher hatching success, and a trend of shorter incubation period. These differences probably arose due to contemporary evolution in invaded areas under strong selective pressures in rice fields, and, together with more favorable climates, enable the snail populations to rapidly grow and expand in southern China.

Flowering Chinese cabbages are widely planted in the south of China and often exposed to acid rain. However, the effect of acid rain on the growth of flowering Chinese cabbage is unclear. In this study, we investigated the influence of simulated acid rain (SAR) on plant height, soil-plant analysis development (SPAD) value (an index for chlorophyll content), proline, malondialdehyde (MDA), antioxidant enzyme activities, nitrogen (N), phosphorus (P), or potassium (K) uptake and variation of soil nutrients. Our results showed that SAR at pH 5.5 did not damage plant development because growth characteristics, photosynthesis, and superoxide dismutase and peroxidase activities did not change obviously at this pH compared to those at pH 7.0. However, 2- to 7-time of SAR exposure at pH 4.5 and pH 3.5 led to the increases of antioxidant enzyme activities, MDA and proline contents, and the decreases of leaf SPAD value and root activity. Nutrient analysis indicated that spraying 4 to 7 times of SAR at pH 3.5 reduced the uptake of N, P and K of flowering Chinese cabbage significantly. In addition, treatment with SAR at pH 3.5 decreased the pH value of the surface soil and the contents of alkaline-hydrolytic N and readily available K but increased that of readily available P in the surface soil by 8.5% to 14.9%. Taken together, our results indicated that SAR at pH 3.5 influenced the antioxidant enzyme system and the contents of soil nutrients, caused metabolic disorders and ultimately restricted the development and growth of flowering Chinese cabbages.

Abstract Pomacea canaliculata, a freshwater snail from South America, has rapidly established natural populations from south to north subtropical region in China, since its original introductions in the 1980s. Low temperature in winter is a limiting factor in the geographic expansion and successfully establishment for apple snail populations. There have been some studies on population level of low temperature tolerance for P. canaliculata, yet little is quantified about its life‐history traits in responses to cold temperatures. Whether these responses vary with the acclimation location is also unclear. We investigated the survivorship and longevity of P. canaliculata in responses to cold temperatures and examine whether these responses vary with the location and snail size. We hypothesized that survival of the snails depends on their shell height and the level of low temperature, and P. canaliculata population from the mid-subtropical zone may exhibit the highest viability over the cold thermal range. We sampled P. canaliculata populations from five latitude and longitude ranges of subtropical China: Guangzhou population in southernmost (SM‐GZ), three populations of Yingtan (MR‐YT), Ningbo (MR‐NB), Ya'an (MR‐YA) in midrange, and Huanggang population in northernmost (NM‐HG) subtropical zone. For each P. canaliculata population, survival and longevity at six cold acclimation temperature levels (12, 9, 6, 3, 0, and −3°C) were quantified, and the effects of location and shell height were examined. The MR‐YA population from mid-subtropical zone of China exhibited the highest survival rate and prolonged survival time regardless of the temperature acclimation treatments, whereas the SM‐GZ population from southern subtropical was the most sensitive to cold temperatures, particular temperatures below 9°C. No individuals of the SM‐GZ population could survive after stressed for 30 days (3°C), 5 days (0°C) and 2 days (−3°C), respectively. For each experimental P. canaliculata population held at 3, 0, and −3°C, individuals with intermediate shell height of 15.0–25.0 mm had significantly higher survivals. The results highlight a request of a more thorough investigation on acclimation responses in each of the life table demographic parameters for P. canaliculata, and pose the question of whether natural selection or some genetic changes may have facilitated adaptation in invasive locations.

Soil microbial community drives the terrestrial carbon (C) cycling by C sources metabolism (i.e., organic C decomposition), however, the microbial response to changing acid rain frequency remains less studied, thus hampering global warming projection. Here, we manipulated a simulated experiment to decipher the impact of acid rain frequency (0, 30%, and 100%) on microbial community and C sources metabolism in the agricultural and forest soils of southern China, based on the phospholipid fatty acids (PLFAs) analysis and BIOLOG method, respectively. We found that changing acid rain frequency did not affect the microbial biomass and community structure of agricultural soil during the whole experiment period, while the 30% and 100% acid rain frequencies significantly decreased the microbial biomass, and altered the microbial community structure of forest soil at the early stage. However, changing acid rain frequency did not influence the microbial C sources metabolism in the agricultural soil, but 30% acid rain frequency significantly reduced the microbial utilization of carboxylic acids in the forest soil. Moreover, increasing acid rain frequency promoted the microbial community dissimilarities of forest soil. The microbial community structure and C sources utilization of agricultural soil were significantly related to soil available phosphorus content, while that of forest soil correlated with the soil available potassium content and temperature. Changes in soil environmental condition, soil acidification parameters and soil nutrients explained most of the variance of microbial community and C sources utilization (81% and 57%, respectively) in the forest soil, whereas great uncertainties of microbial community and C sources utilization existed in the agricultural soil with the explanatory proportion being 20% and 10%, respectively. Our findings suggest that the microbial community of forest soil is more sensitive to changing acid rain frequency than that of agricultural soil in a short term. These results support the prediction of microbes-driven C cycling dynamics in specific soil ecosystems in the context of changing acid rain frequency.

Contamination of microplastics (MPs) is a global environmental issue that has received much attention from the scientific and public communities due to ecological concerns in recent decades. Comparing with aquatic ecosystems, soil systems, regardless of the high importance and complexity, have been less studied under widely existing and increasing MP contamination. This review, combined with data assimilation and meta-analysis methods, has summarized current contamination conditions of soil MPs across different sites reported in earlier studies. While performing this meta-analysis, we investigated the effects of MPs on soil biota including their numbers, biomass, diversity, and physiological properties. The results showed that abundance of soil MPs ranged from 0.34 to 410958.9 items kg-1 and concentration ranged from 0.002 to 67500 mg kg-1 across sites, with agricultural soils containing significantly lower abundance and concentration of MPs than others. Presence of MPs significantly decreased the individual number of soil biota, operational taxonomic unit, diversity index (Simpson), movement index and reproduction rate, whereas the mortality rate was significantly increased by the soil MPs. Despite these significant effects, MPs did not significantly alter the biomass of soil biota, which could be due to a counteraction of their negative and positive effects on different groups of soil organisms. Moreover, we observed that soil MPs could significantly increase the Chao1 index, suggesting that MPs may act as a food resource for the soil rare biosphere. Based on the existing knowledge, we suggest that future studies should focus on research areas that include but are not limited to methodological improvements, intensive field investigations, risk assessment from the perspective of soil food web and bioaccumulation, MPs induced antibiotic resistance, and restoration strategies to reduce their concentrations in soil.

Light is a crucial environmental factor implicated in the temporal regulation of important biological events of insects, and some insects are usually sexually active in dark periods. However, the effects of light during dark periods on the growth, development, and fecundity of Spodoptera frugiperda, an important agricultural pest, remain unknown. In this study, we evaluated the effects of lighting in dark periods on the biological parameters of S. frugiperda in laboratory conditions. Our results showed that lighting in dark periods significantly prolonged the pre-adult stage and reduced the pupal survival and emergence rate. Moreover, the results indicated that the adult stage is the photoperiod-sensitive stage of S. frugiperda, and the fecundity and longevity of adults significantly reduced under lighting in dark periods, and the number of eggs per female moth decreased by 99% compared with the control. The mean generation time (T) of S. frugiperda population was the longest, and the intrinsic rate of natural increase (r) and finite rate of increase (λ) were the smallest under lighting in dark periods, and the population growth of S. frugiperda was significantly limited. Our findings may provide valuable insights to develop effective integrated pest management strategies to control S. frugiperda.

Acid rain alters soil carbon (C) cycling by influencing the soil microbial community structure and functions. However, the response of soil microbial communities to acid rain with time and underlying mechanisms are still poorly understood. Herein, we conducted a one-year intact soil core experiment to investigate the temporal changes of soil microbial community composition and C sources metabolism under acid rain (pH 5.0, pH 4.0, and pH 3.0) in an agricultural soil of southern China. We found that pH 3.0 acid rain increased the total, bacterial, gram-positive bacterial, and actinomycetal PLFAs at the early stage, but this effect diminished with time. Conversely, the gram-negative bacterial PLFAs contents were reduced under pH 3.0 acid rain at the later stage. Interestingly, pH 5.0 acid rain increased the total, bacterial, gram-positive bacterial, and actinomycetal PLFAs contents at the later stage. In addition, pH 3.0 and pH 5.0 acid rain treatments accordingly altered the soil microbial community structure at the early and later stage. However, acid rain did not change the microbial C sources utilization pattern. The principal response curve analysis revealed that the seasonal variation exerted a greater effect on the overall variance of soil microbial community structure than the acidity of acid rain. Our results demonstrate the asynchronous response of soil microbial community structure and function, which implies that the microbial functional redundancy may exist in the subtropical agricultural soil under acid rain.

Sustained nitrogen (N) deposition has a wide-ranging impact on terrestrial ecosystems. However, still little attention has been paid to responses of urban soil fauna to the increasing N deposition. To clarify such effects on the soil properties and soil fauna in typical urban lawns (featuring Cynodon dactylon vegetation), a control experiment was conducted for 1 year, in which NH4NO3 was added as the external N source with four treatments of N addition: N0 (i.e., only water), N1 (50 kg N ha–1 yr–1), N2 (100 kg N ha–1 yr–1), N3 (150 kg N ha–1 yr–1). Results showed that N additions influence soil faunal communities in the urban lawns soil. The relative abundance of Oribatida increased with the N treatment level, partially replacing the more sensitive Collembola. Significant differences in the Shannon-Wiener and Margalef indices (p < 0.01) supported this statement. Although higher doses of N addition showed adverse effects on soil fauna communities, low N inputs increased the soil fauna diversity and richness, especially at 5–10 cm depth. A threshold effect appears to exist: low N addition (

The successful establishment of invasive populations is closely linked to environmental factors. It is unclear whether coexisting species in the native area follow the same genetic pattern in the invaded continents under the local climate factors. Two coexisting morphologically similar snails (Pomacea canaliculata and P. maculata), native to tropical and sub-tropical South America, have become invasive species for agriculture production and wetland conservation across five continents over 40 years. We analyzed the correlation between the genetic diversity of the two snails and the climate factors or habitat changes. Based on the 962 sequences from the invaded continents and South America, the nucleotide diversity in the agricultural habitat was low for P. canaliculata, whereas it was high for P. maculata, compared with that in the non-agricultural habitat. The two snails showed a divided population structure among the five continents. The P. canaliculata population in the invaded continents has remained stable, whereas the P. maculata population expanded suddenly. Seven main haplotype networks and two ancestral haplotypes (Pc3, Pm1) were found in the P. canaliculata and P. maculata populations. The haplotypes of the two snails were related to local climate factors. The overall fixation index of P. canaliculata and P. maculata was 0.2657 and 0.3097 between the invaded continents and South America. The population expansion of the two snails fitted the isolation-by-distance model. We discovered nine new sequences from the sampling locations. Overall, the genetic diversity and genetic differentiation of the two invasive snails were closely related to geographic separation, agricultural habitat, and climate factors.

The level of acidity in rainfall can alter soil nutrient cycling (e.g., carbon [C] cycling), while the effect of changing acid rain frequency on soil C cycling and involved microbial communities remains largely understudied. Here, we manipulated a laboratory intact soil core experiment to test the effect of acid rain frequency (0, 30% and 100%) on soil CO2 emission, microbial communities, and microbial metabolism of various carbon sources in the agricultural and forest soils in southern China. We found idiosyncratic responses of soil microbial communities and carbon utilization to acid rain frequency in two different soil ecosystems. The high acid rain frequency (100%) substantially reduced soil microbial biomass, particularly that of gram-negative bacteria in the forest soil, while this effect was not observed in the agricultural soil. Moreover, acid rain frequencies (30% and 100%) significantly reduced the microbial utilization of amines/amides in the agricultural soil, while they did not alter the carbon sources utilization in the forest soil. However, surprisingly, both the acid rain treatments did not affect the soil CO2 emission in the agricultural and forest soils, suggesting a complex relationship between soil microbial biomass or abundance and CO2 emission. Our results suggest that the agricultural and forest soils have idiosyncratic responses to changing acid rain frequency, probably because of differences in their biological and physicochemical properties.

Geological factors are key elements to control shale gas enrichment and influence the accurate estimation of shale gas reserve. However, the impact of the main geological factors, such as porosity, mineralogy, and organic matter, on marine shale gas enrichment and reserve calculation has not yet been fully clarified. Herein, we measured gas adsorption, porosity, mineralogical composition, and total organic carbon content of the marine shale samples from the Jiaoshiba area of Fuling gas field in Sichuan Basin, South China, and investigate the relationships between the geological factors and the adsorbed gas content. The results show that adsorbed gas content is positively correlated with total organic carbon and porosity; the larger specific surface area of samples with more clay minerals essentially contributes to shale gas enrichment. Additionally, the sealing of faults imposes a significant impact on shale gas accumulation. The probability volume method was applied to calculate the shale gas reserve. The reserves of P90 (the most pessimistic reserve), P50 (the most likely reserve), and P10 (the most optimistic reserve) were calculated, respectively, which provides useful information to reduce the risk in shale gas development.

Rice is widely planted and serves as staple food in the world, but it is often exposed to acid rain and rice blast (Pyricularia oryzae). In this work, we analyzed the effects of co-exposure to simulated acid rain (SAR) and P. oryzae on the photosynthetic growth of rice seedlings. We found that the growth, photosynthesis, and chloroplast ultrastructure of rice seedlings were damaged under single treatments of P. oryzae and strong acid rain (pH 2.0) but increased under medium acidity acid rain (pH 4.0). Similarly, when plants were exposed to both P. oryzae and acid rain, pH 4.0 mitigated the changes of growth, photosynthetic characteristics, and chloroplast ultrastructure induced by P. oryzae, but pH 2.0 aggravated these changes. In addition, we found that significant differences in chlorophyll content (chlorophyll a and chlorophyll b) correlated with transpiration rate (Tr) under the combined stress of acid rain and P. oryzae at pH 4.0 and pH 2.0. Medium-acidity acid rain alleviated the harm caused by P. oryzae on rice growth by enhancing synergistic regulatory mechanisms of photosynthetic traits to increase plant resistance tolerance. The effect of P. oryzae on photosynthetic traits of rice was regulated by acidity of acid rain.

Economic losses and environmental hazards are meaningful problems of emitted ammonia induced by extensive use of synthetic nitrogen fertilizers. The concept presented as yield scaled fertilizer productivity (YSFP) in our meta-analysis in addition to nitrogen use efficiency (NUE), nitrogen agronomic efficiency (NAE), and productivity of applied nitrogen (PAN) were used to weight ammonia emission (AV)-induced reductions in wheat, maize, and rice production. The comprehensive meta-analysis was used to weight the reductions in these parameters by AV as the difference between observed means of the collected studies and their adjusted means using AV factor. There were higher reductions in agronomic production induced by AV in rice than maize and wheat. AV-induced reductions in PAN of rice, maize, and wheat were decreased by 4.99, 3.71, and 2.42 (kg grains kg−1 N), respectively. YSFP and PAN recorded the highest sensitivity to AV in wheat (R2 = 0.88 for both) and rice (R2 = 0.92 and 0.89, respectively), while NUE was the most efficient parameter in weighting AV induced agronomic effects in maize (R2 = 0.81). Slow-released N fertilizers resulted in the lowest reductions in AV induced agronomic losses followed by organic amendments and then urea while using other synthetic fertilizers recorded the highest reductions by 3.90, 6.40, 1.41, and 4.70 in YSFP, NUE, NAE, and PAN, respectively. Inhibitors had the highest effect on mitigating AV induced agronomic losses compared with biochar and mulching and affected the parameters following that order as percentages of no amendments, YSFP (52.63%) > PAN (47.18%) > NUE (40.83%) > NAE (38.75%). This study outlines the reductions in agronomic production induced by AV and weights the efficiency of various mitigation strategies under various agronomic conditions. The results proved the efficiency of YSFP with NUE parameters to weight the effect of AV on crop yield, while suggesting to find out more applicable parameters in further studies.

Cereal/legume intercropping is an effective agricultural practice for pest and disease control and crop production. However, global research on rice and aquatic legume intercropping is relatively rare. A field experiment during two seasons (2018 late season and 2019 early season) was conducted to explore the effects of rice and water mimosa intercropping on rice canopy microclimate, pest and disease, yield, grain quality, and economic income. Two cultivation patterns including rice/water mimosa intercropping and rice monocropping were employed, and three nitrogen (N) fertilizer application levels, including zero N (ZN, 0 kg ha−1 N), reduced N (RN, 140 kg ha−1 N), and conventional N (CN, 180 kg ha−1 N) levels, were applied for the above two cultivation patterns. The results showed that rice/water mimosa intercropping formed a canopy microclimate of rice with higher temperature and lower relative humidity and dew point temperature. In addition, there was a significant reduction in the occurrences of rice leaf blast by 15.05%~35.49%, leaf folders by 25.32%~43.40%, and sheath blight by 16.35%~41.91% in the intercropping treatments. Moreover, rice/water mimosa intercropping increased rice per unit yield by 43.00%~53.10% in the late season of 2018 and 21.40%~26.18% in the early season of 2019. Furthermore, rice grain quality was totally improved, among which brown and head rice rates increased but rice chalky rate and chalkiness degree decreased in the intercropping system. We suggest that combining rice/water mimosa intercropping and N fertilizer reduction can be used as an environmentally friendly eco-farming technique because it can decrease N fertilizer application by approximately 40 kg·ha−1. This combination would not only mitigate nonpoint source pollution but also obtain advantages for controlling rice pests and diseases that would alleviate pesticide usage and improve rice yield and grain quality, which can be extended for green rice production to increase income for producers.

Anthropogenic nitrogen (N) and sulfur (S) deposition can change above- and belowground biodiversity, including soil microbial diversity. The diversity of denitrifying microorganisms is of great significance to the calculation of the global nitrogen cycle and nitrogen flux. For a long time, nirK and nirS have been used as the functional genes to study denitrifying microorganisms, and have gradually become molecular markers for studying the composition and diversity of denitrifying bacteria. Here, three-time exposures to N and S applications (7, 30, and 60 days), were independently established. Additionally, the abundance, diversity, and structure of nirK- and nirS-type denitrifying communities were examined by sequencing analyses in response to three treatments, namely, N and S (TN/S), sodium chloride (TNaCl) and deionized water (pH = 7.0) (CK). Our results suggest that TN/S led to higher electrical conductivity (EC), total nitrogen (TN), total organic carbon (TOC), nitrate nitrogen (NO3−-N), ammonium nitrogen (NH4+-N), and lower pH compared with TNaCl and CK, which affected the diversity of nirK- and nirS-type denitrifying bacterial communities. We also observed that the nirK-type denitrifying community demonstrated a higher sensitivity to N and S additions. Overall, our results are important for the understanding of nitrogen in soil and N2O emissions.

Despite evidence from previous case studies showing that agronomic traits partially determine the resulting yield of different rice (Oryza sativa L.) varieties, it remains unclear whether this is true at the ecotype level. Here, an extensive dataset of the traits of 7686 rice varieties, released in China from 1978 to 2017, was used to study the relationship between yield and other agronomic traits. We assessed the association between yield and other agronomic traits for four different rice ecotypes, i.e., indica inbred, indica hybrid, japonica inbred, and japonica hybrid. We found that associations between agronomic traits and yield were ecotype-dependent. For both the indica inbred and indica hybrid ecotypes, we found that greater values of certain traits, including the filled grain number per panicle, 1000-grain-weight, plant height, panicle length, grains per panicle, seed setting rate, long growth period, low panicle number per unit area, and low seed length/width ratio, have accounted for high grain yield. In the japonica inbred and japonica hybrid ecotypes, we found that only high panicle number per unit area and long growth period led to high grain yield. Indirectly, growth period consistently had a positive effect on yield in all ecotypes, and plant height had a positive effect on yield for the indicas and japonica inbred only. Plant height had a negative effect for the japonica hybrid. Altogether, our findings potentially have valuable implications for improving the breeds of rice ecotypes.

Land-use/cover is one of the major factors that affect the ecosystem and the services it provides. The impact of land-use change on ecosystem service value is a hotspot in developing countries, especially China—a region with rapid economic development and rapid population growth. As the leading area of China’s reform and opening-up, Guangdong province in southern China is subjected to land-use conversion that significantly alters the capacity of natural ecosystem to provide ecosystem services supporting human well-being. We analyzed the characteristics of land-use changes from 1990 to 2018 using the four-phase land-use data interpreted from Landsat satellite images. We estimated the ecosystem service value through a well-established benefit transfer method using modified local value coefficients, analyzed the trade-offs and synergies among ecosystem services through ecosystem service trade-off degree, and compared the relationship between ecosystem services value, economic development, and population in Guangdong province. The results indicated that the following: (1) Built-Up Area drastically expanded from 6783.1 km2 in 1990 to 13,142.0 km2 in 2018 (93.7%), especially in the Pearl River Delta, where the growth rate of Built-Up Area expansion was up to 169.0%. The other land-use types were all contracted as Cropland (−10.9%), Forestland (−1.0%), Grassland (−4.0%), Water Body (−2.1%), and Unused Land (−24.4%). (2) Total ecosystem service value decreased from US$121,666 billion in 1990 to US$116,432 billion in 2018 (−4.3%). Cropland, Forestland, and Water Body played the most important roles for the total ecosystem service value. Water supply experienced the largest declines in ecosystem services value (US$ −1866.3 million, −10.1%), followed by waste treatment (7.6%) and gas regulation (−4.9%). (3) Synergy was the dominant relationship among ecosystem services. The above results can not only serve as reference case for other provinces/regions/countries/ to carry out relevant research work but also provide much focus on land-use planning to manage the impacts of land-use change on regional ecosystem services function.

Alginate oligosaccharides (AOS) are known for functions in regulating plant growth and stress resistance. This study investigated the damage on rice leaves caused by acid rain (AR) and high temperature (HT) simultaneously, as well as the alleviating effect of AOS on these stresses. The results show that plant biomass and antioxidant enzyme activities (AEAs) after AR treatment reduced more severely under HT conditions than normal-temperature conditions. Both AR and HT triggered the accumulation of reactive oxygen species (ROS) in rice leaves. The suppressing effects of AR and HT were individual in most cases, except for AEAs. Microscopic analysis showed that pH 2 AR and HT injured leaf epidermis, particularly the bulliform cells, the veins and interveinal regions. Spraying AOS resulted in a slight elevation of biomass, a significant increase in AEAs and a remarkable decline in ROS concentrations under HT conditions with AR. Besides, the chlorophyll a contents of a leaf after pH 2 AR plus AOS treatment under HT conditions remained 66.1% of that after pH 7 treatment under normal-temperature conditions. Moreover, AOS protected the integrity of leaf tissue even after pH 3 treatment. Taken together, the above results suggest that AR and HT inhibited AEAs, led to the accumulation of ROS and damaged rice leaf. However, foliar applying AOS enhanced AEAs, scavenged ROS, and thus alleviated the stress induced by HT and AR.

Acid rain (AR), as a global environmental threat, has profoundly adverse effects on natural soil ecosystems. Microorganisms involved in the nitrogen (N) cycle regulate the global N balance and climate stabilization, but little is known whether and how AR influences the structure and complexity of these microbial communities. Herein, we conducted an intact soil core experiment by manipulating the acidity of simulated rain (pH 7.5 (control, CK) vs. pH 4.0 (AR)) in subtropical agricultural soil, to reveal the differences in the structure and complexity of soil nitrifying and denitrifying microbiota using Illumina amplicon sequencing of functional genes (amoA, nirS, and nosZ). Networks of ammonia-oxidizing archaea (AOA) and nirS-carrying denitrifiers in AR treatment were less complex with fewer nodes and lower connectivity, while network of nosZ-carrying denitrifiers in AR treatment had higher complexity and connectivity relative to CK. Supporting this, AR reduced the abundance of keystone taxa in networks of AOA and nirS-carrying denitrifiers, but increased the abundance of keystone taxa in nosZ-carrying denitrifiers network. However, AR did not alter the community structure of AOA, ammonia-oxidizing bacteria (AOB), nirS-, and nosZ-carrying denitrifiers. Moreover, AR did not change soil N2O emissions during the experimental period. AOB community structure significantly correlated with content of soil available phosphorus (P), while the community structures of nirS- and nosZ-carrying denitrifiers both correlated with soil pH and available P content. Soil N2O emission was mainly driven by the nirS-carrying denitrifiers. Our results present new perspective on the impacts of AR on soil N-cycle microbial network complexity and keystone taxa in the context of global changes.

Atmospheric nitrogen (N) deposition is changing in both load quantity and chemical composition. The load effects have been studied extensively, whereas the composition effects remain poorly understood. We conducted a microcosm experiment to study how N chemistry affected the soil microbial community composition characterized by phospholipid fatty acids (PLFAs) and activity indicated by microbial CO2 release. Surface and subsurface soils collected from an old-growth subtropical forest were supplemented with three N-containing materials (ammonium, nitrate, and urea) at the current regional deposition load (50 kg ha-1 yr-1) and incubated at three temperatures (10, 20, and 30°C) to detect the interactive effects of N deposition and temperature. The results showed that the additions of N, regardless of form, did not alter the microbial PLFAs at any of the three temperatures. However, the addition of urea significantly stimulated soil CO2 release in the early incubation stage. Compared with the control, N addition consistently reduced the temperature dependency of microbial respiration, implying that N deposition could potentially weaken the positive feedback of the warming-stimulated soil CO2 release to the atmosphere. The consistent N effects for the surface and subsurface soils suggest that the effects of N on soil microbial communities may be independent of soil chemical contents and stoichiometry.

Coupled cropping-breeding modes have been highly recommended due to their ecological and sustainable nature. Integrated rice-duck farming is a typical ecological planting system in rice paddy fields and has been widely popularized in Asia where a considerable area of cropland has been planting rice. In this study, two experimental treatments of turbid water or rice-duck treatment were established to compare with the control and a conventional treatment in absence of ducks. The turbid water treatment imitated the muddying effect by duck activities with the trampling and foraging effects excluded, while the rice-duck treatment included all of the mentioned effects by raising ducks in rice paddy field. Results showed that the rice-duck treatment significantly reduced soil seed bank density by more than 40% and the figures under the turbid water treatment were 18.2% and 30.5%, accordingly, in the early and late rice growing seasons. Moreover, the rice-duck treatment significantly altered the vertical distribution of soil seed bank by substantially declining the seed density in the topsoil (0−5 cm). Changes in soil seed bank density considerably contributed to the declines in above-ground weed density because a significant correlation was detected between the soil seed bank density in the early season and the weed density in the late season. Our results of declined soil seed bank and weed density in integrated rice-duck farming imply that this system is highly efficient as a biological pathway for controlling weeds.

Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in "100 of the World's Worst Invasive Alien Species"; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest "attack rates" a, shortest "handling times" h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.