@article{li_chen_yuan_li_zhuang_2024, title={Characterization of controlling factors for soil organic carbon stocks in one Karst region of Southwest China}, volume={19}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0296711}, abstractNote={Soil organic carbon (SOC) contributes the most significant portion of carbon storage in the terrestrial ecosystem. The potential for variability in carbon losses from soil can lead to severe consequences such as climate change. While extensive studies have been conducted to characterize how land cover type, soil texture, and topography impact the distribution of SOC stocks across different ecosystems, little is known about in Karst Region. Here, we characterized SOC stocks with intensive sampling at the local scale (495 representative samples) via Random Forest Regression (RF) and Principal Component Analysis (PCA). Our findings revealed significant differences in SOC stock among land cover types, with croplands exhibiting the lowest SOC stocks, indicating that management practices could play a crucial role in SOC stocks. Conversely, there was little correlation between SOC stock and clay percentage, suggesting that soil texture was not a primary factor influencing SOC at a local scale. Further, Annual Precipitation was identified as the key driving factor for the dynamics of SOC stocks with the help of RF and PCA. A substantial SOC deficit was observed in most soils in this study, as evaluated by a SOC/clay ratio, indicating a significant potential in SOC sequestration with practical measures in the karst region. As such, future research focused on simulating SOC dynamics in the context of climate change should consider the controlling factors at a local scale and summarize them carefully during the up-scaling process.}, number={1}, journal={PLOS ONE}, author={Li, Qiang and Chen, Baoshan and Yuan, Hezhong and Li, Hui and Zhuang, Shunyao}, year={2024}, month={Jan} }
 @article{azeem_sun_jeyasundar_han_li_abdelrahman_shaheen_zhu_li_2023, title={Biochar-derived dissolved organic matter (BDOM) and its influence on soil microbial community composition, function, and activity: A review}, ISSN={["1547-6537"]}, DOI={10.1080/10643389.2023.2190333}, abstractNote={Abstract Biochar-derived dissolved organic matter (BDOM) plays key roles in soil ecosystem by affecting soil physicochemical and biological properties and supplying nutrients to soil microbes. It can either enhance or suppress the growth of certain soil microorganisms, depending on its composition and content of labile organic compounds. This review aims to discuss and summarize the role of BDOM in modifying soil microbial functioning, microbial community structure, and enzymatic activity. We mainly focus on the role of BDOM as a function of its concentration, type of feedstock biomass, and pyrolysis temperature (PT). Results show that saw dust- and manure-based biochars produce higher BDOM concentrations than straw-, bone-, and sludge-based biochars. The types of feedstock biomass and its PT determine BDOM characteristics and its interaction with soil microbial communities. Plant-derived biochar with pyrolysis temperature ≤300 °C often results in a more aliphatic BDOM than that with pyrolysis temperature ≥500 °C, which yields a more aromatic BDOM. BDOM of plant biochar contains higher specific ultraviolet absorbance (SUVA) and humification index (HIX) than that of manure biochar. The SUVA and HIX of BDOM positively correlate (R 2=0.68–0.96) with the content of total fatty acid methyl esters, but negatively correlate with the abundances of actinomycetes, arbuscular mycorrhizae, and fungal communities. However, the environmental fate of BDOM in biochar amended soil requires long-term experiment, both in laboratory and field scales, to provide a full understating of BDOM interaction with soil organic matter and microorganisms and help to tailor a safe utilization of biochar in agroecosystems.}, journal={CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY}, author={Azeem, Muhammad and Sun, Tian-Ran and Jeyasundar, Parimala Gnana Soundari Arockiam and Han, Rui-Xia and Li, Hui and Abdelrahman, Hamada and Shaheen, Sabry M. and Zhu, Yong-Guan and Li, Gang}, year={2023}, month={Mar} }
 @article{you_wang_sun_liu_fang_kong_zhang_xie_zheng_li_et al._2023, title={Hydrochar more effectively mitigated nitrous oxide emissions than pyrochar from a coastal soil of the Yellow River Delta, China}, volume={858}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2022.159628}, abstractNote={Application of char amendments (e.g., pyrochar or biochar, hydrochar) in degraded soils is proposed as a promising solution for mitigating climate change via carbon sequestration and greenhouse gases (GHGs) emission reduction. However, the hydrochar-mediated microbial modulation mechanisms underlying N2O emissions from coastal salt-affected soils, one of essential blue C ecosystems, were poorly understood. Therefore, a wheat straw derived hydrochar (SHC) produced at 220 °C was prepared to investigate its effects on N2O emissions from a coastal salt-affected soil in the Yellow River Delta and to distinguish the microbial regulation mechanisms in comparison with corresponding pyrochar pyrolyzed at 500 °C (SPC) using a 28-day soil microcosm experiment. Compared with SPC, the acidic SHC (pH 4.15) enriched in oxygenated functional groups, labile C and N constituents. SHC application more efficiently depressed cumulative soil N2O emissions (48.4-61.1 % vs 5.57-45.2 %) than those of SPC. SHC-induced inhibition of ammonia-oxidizing gene (amoA)-mediated nitrification and promotion of full reduction of N2O to N2 by nitrous oxide reductase gene (nosZ) were the underlying microbial mechanisms. Structural equation models further revealed that SHC-modulated bacterial N-transformation responses, i.e., inhibited nitrification and promoted heterotrophic denitrification, mainly contributed to reduced N2O emissions, whereas modification of soil properties (e.g., decreased pH, increased total C content) by SPC dominantly accounted for decreased N2O emissions. These results address new insights into microbial regulation of N2O emission reduction from the coastal salt-affected soils amended with hydrochar, and provide the promising strategies to enhance C sequestration and mitigate GHG emissions in the blue C ecosystems.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={You, Xiangwei and Wang, Xiao and Sun, Ruixue and Liu, Qiang and Fang, Song and Kong, Qingxian and Zhang, Xin and Xie, Chenghao and Zheng, Hao and Li, Hui and et al.}, year={2023}, month={Feb} }
 @article{zhang_li_chen_zhu_pedersen_gu_wang_li_liu_zhou_et al._2023, title={Methylmercury Degradation by Trivalent Manganese}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.3c00532}, abstractNote={Methylmercury (MeHg) is a potent neurotoxin and has great adverse health impacts on humans. Organisms and sunlight-mediated demethylation are well-known detoxification pathways of MeHg, yet whether abiotic environmental components contribute to MeHg degradation remains poorly known. Here, we report that MeHg can be degraded by trivalent manganese (Mn(III)), a naturally occurring and widespread oxidant. We found that 28 ± 4% MeHg could be degraded by Mn(III) located on synthesized Mn dioxide (MnO2-x) surfaces during the reaction of 0.91 μg·L-1 MeHg and 5 g·L-1 mineral at an initial pH of 6.0 for 12 h in 10 mM NaNO3 at 25 °C. The presence of low-molecular-weight organic acids (e.g., oxalate and citrate) substantially enhances MeHg degradation by MnO2-x via the formation of soluble Mn(III)-ligand complexes, leading to the cleavage of the carbon-Hg bond. MeHg can also be degraded by reactions with Mn(III)-pyrophosphate complexes, with apparent degradation rate constants comparable to those by biotic and photolytic degradation. Thiol ligands (cysteine and glutathione) show negligible effects on MeHg demethylation by Mn(III). This research demonstrates potential roles of Mn(III) in degrading MeHg in natural environments, which may be further explored for remediating heavily polluted soils and engineered systems containing MeHg.}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Zhang, Shuang and Li, Baohui and Chen, Yi and Zhu, Mengqiang and Pedersen, Joel A. and Gu, Baohua and Wang, Zimeng and Li, Hui and Liu, Jinling and Zhou, Xin-Quan and et al.}, year={2023}, month={Mar} }
 @article{wang_li_cheng_yao_li_you_zhang_li_2023, title={Wheat straw hydrochar induced negative priming effect on carbon decomposition in a coastal soil}, volume={2}, ISSN={["2770-596X"]}, DOI={10.1002/imt2.134}, abstractNote={The mechanisms underlying hydrochar-regulated soil organic carbon (SOC) decomposition in the coastal salt-affected soils were first investigated. Straw-derived hydrochar (SHC)-induced C-transformation bacterial modulation and soil aggregation enhancement primarily accounted for negative priming effects. Modification of soil properties (e.g., decreased pH and increased C/N ratios) by straw-derived pyrochar (SPC) was responsible for decreased SOC decomposition. Progressive land-use changes, deforestation, and the excessive combustion of fossil fuels have increased greenhouse gas (GHG) emissions and the widespread intensification of extreme weather events [1]. Global CO2 emissions have reached approximately 31.5 gigatons per year and are projected to triple by 2050 [2]. To address this issue, the Intergovernmental Panel on Climate Change (IPCC) appealed for GHG mitigation strategies [3]. As a typical representative of marginal soils, coastal salt-affected soils, also referred to as blue C ecosystems [4], are beneficial for climate resilience and C sequestration [4]. However, in recent years, coastal soils have suffered from soil deterioration. Salt stress and nutrient deficiency caused the regression and degradation of soil primary productivity and substantial loss of blue C (0.15–1.02 Pg of CO2 released from the soil annually) from the coastal soils [5]. Therefore, reclaiming soil primary productivity is an urgent task to recover the ecological functions of these blue C ecosystems for climate change mitigation. Char amendment (e.g., pyrochar and hydrochar) as a soil C sequestration material has gained considerable attention for CO2 emission mitigation [6, 7]. Char amendment can increase, decrease, or have no effect on soil organic carbon (SOC) decomposition, corresponding to positive, negative, and no priming effect [8, 9]. Pyrochars, also known as biochars, are produced from the pyrolysis of dried biomass (e.g., straw wastes, sewage sludge, and animal manure) at 300–700°C [10]. Comparably, hydrochar produced from hydrothermal carbonization of wet biomass at lower temperatures (180–370°C) was an alternative method to pyrolysis for producing carbonaceous materials for soil C sequestration [11]. Given the considerable differences in thermal conversion and biomass conditions, the characteristics of hydrochars differ from those of pyrochars, which consequently affect their performance in CO2 emission mitigation [11, 12]. However, to date, most studies have focused on pyrochar effects on soil CO2 emission [13, 14] and limited attention has been paid to the corresponding effects of hydrochars. Hydrochars have a low C sequestration potential for soils, mainly attributable to their high decomposability, and thus provide high-level, easily degradable C and N sources for soil microbial activity [15]. Conversely, rice straw- and pig manure-derived hydrochars decrease soil CO2 emissions due to the low bioavailability of inherent labile C and high C aromaticity [16]. Moreover, previous hydrochar studies have primarily focused on nonsalt-affected soils, while data on salt-affected soils remain limited. Compared with nonsalt-affected soils, salt-affected soils have low primary productivity and deteriorated physical structure, resulting in little input of exogenous organic matter [17] and weak protection of SOC by soil aggregates [18]. Corn straw-derived pyrochars at 350°C and 550°C, characterized by high cation exchange capacity (CEC) and oxygen-containing functional groups (e.g., –COOH and –OH), could decrease SOC decomposition (negative priming effect) mainly through promoting soil aggregation and shifting of bacterial community composition toward low C turnover bacteria in a coastal salt-affected soil [19, 20]. The labile C component of char amendments can stimulate the secretion of functional cementing metabolites (e.g., proteins and organic acids) or residues by soil microorganisms to enhance soil aggregation, thereby decreasing SOC decomposition [21]. Unlike pyrochars, hydrochars with relatively higher amounts of labile C and N fractions could be more favorable for increasing microbial biomass abundance and shifting community composition and C-cycling functions by altering soil organic matter (SOM) composition, substrate availability, and soil physicochemical properties (e.g., pH and enzyme activity), thus affecting SOC cycling [11]. It was reported that hydrochars could increase stable SOC fraction, mainly aromatic compounds, by decreasing the relative abundance of active bacterial decomposers of resistant SOC [22]. Additionally, the abundant O-containing functional groups on hydrochars may enhance the soil aggregate stability to a greater extent than those on pyrochars by promoting the formation of char–organic matter–mineral complexes via hydrogen bonding and ligand exchange, thereby enhancing the physical protection of SOC by soil aggregates [19, 20]. However, the mechanisms of hydrochar-mediated soil aggregation and microbially compositional and functional responses responsible for SOC decomposition in the coastal salt-affected soils were poorly understood. To address this knowledge gap, a wheat straw-derived hydrochar (SHC) produced at 220°C was prepared to investigate its effects on SOC decomposition from a coastal salt-affected soil and the underlying microbial regulation and soil aggregation enhancement mechanisms in comparison with corresponding wheat straw-derived pyrochar (SPC) pyrolyzed at 500°C using a 28-day soil microcosm experiment; the objectives of this study are to: (1) compare the effects of SHC and SPC on SOC decomposition in coastal salt-affected soil, (2) elucidate the mechanisms underlying char-mediated soil aggregation and SOM composition associated with SOC decomposition, (3) identify the compositional and C metabolic responses of soil microbial communities to char amendments, and (4) elucidate the dominant factors determining char-affected SOC decomposition. The CO2 fluxes in all soils generally increased with the prolonged incubation period, peaking on day 4, then gradually decreased in the later incubation period (Figure 1A). On day 4, SHC amendment at 1% and 3% markedly increased soil CO2 flux compared with that seen with soil without char amendment (CK) treatment, in the order of SHC at 3% > SHC at 1% (Figure 1A). Comparably, both SPC amendments at 1% and 3% exerted little effect on maximum soil CO2 fluxes relative to CK treatment. SHC amendment at 1% and 3% increased the cumulative soil CO2 emission by the end of the 28-day incubation by 316% (959 mg/kg) and 1176% (2936 mg/kg) compared with CK, respectively (Figure 1B). The physicochemical properties of hydrochar and pyrochar were analyzed and are described in the Text S1. SHC contained a relatively higher dissolved organic carbon (DOC) content than SPC (104 vs. 2.42 mg/g, Table S1), which can act as labile C or bioavailable C fractions to be mineralized into CO2 by soil microbes, thereby contributing to the total cumulative CO2 emissions from soils amended with chars [14]. Consequently, the difference in DOC content between the SHC and SPC could affect their priming effects on SOC decomposition [14, 19]. Therefore, the net priming effects of SHC and SPC on SOC decomposition were calculated by subtracting the possible maximum C decomposition amount of SHC and SPC from the total detected cumulative CO2 emission [14] according to the DOC content of SHC and SPC (Figure 1B). For the SHC treatments, the increased CO2 emission (959–2936 mg/kg) induced by SHC amendments compared with that of CK treatment was lower than the total labile C amount of SHC (DOC, 1040–3120 mg/kg) (Table S1) added to the 1% and 3% SHC-treated soils. This result suggested that SHC at 1% and 3% (w/w) could decrease SOC decomposition (negative priming effect) correspondingly up to 337 and 440 mg/kg (Figure 1C), respectively, in the coastal salt-affected soils during a 28-day incubation [14, 19]. Comparably, excluding the CO2 emitted from labile C degradation of SPC (DOC, 24.2–72.6 mg/kg) (Table S1) from overall CO2 emissions, SPC amendments at 1% and 3% induced negative priming effect up to 29.2 and 73.7 mg/kg, respectively (Figure 1C). This strongly agrees with our previous studies showing that pyrochar application to coastal salt-affected soil resulted in a decrease in SOC decomposition [14, 19]. These results collectively confirm our hypothesis that SHC induces a greater negative priming effect on SOC decomposition in coastal salt-affected soils than SPC. In the present study, the different effects of SOC decomposition induced by the SPC and SHC amendments could be mainly due to their different effects on soil physicochemical properties, including the distribution pattern and stability of soil aggregates, SOM availability, and microbial community responses. The different char-induced SOC decomposition effects could be attributed to differences in char characteristics (Text S1). Relative to the SPC, the abundant carboxylic (–COOH) and hydroxyl (–OH) groups (Figure S1) in SHC could supply more adsorption sites for the labile C substrate, thereby resulting in a greater reduction in C availability for microbial utilization. However, the DOC contents in the SPC and SHC treatments were similar to that in the CK soil (Figure S2), excluding the direct sorption/immobilization of SOM by char amendments, which was the primary reason for the negative priming effect. However, compared with SPC, SHC with abundant O-containing functional groups, could more efficiently enhance the stability of soil aggregates [19]. This may account for the greater SHC-priming effect of SOC decomposition compared with that of SPC. Additionally, SPC and SHC can affect the diversity and composition of the soil microbial community and related enzymatic activities responsible for regulating soil C biochemical cycles and CO2 emission [22, 23]. Soil microbial metabolic activity is a key factor driving soil C cycling, especially SOC decomposition [24, 25]. As an important active component of soil C resources, microbial biomass carbon (MBC) is a sensitive indicator of soil process changes and contributes to the improved biological health of salt-affected soils [26]. The microbial metabolic quotient is defined as the respiration rate per unit time of soil MBC and is generally used to measure microbial carbon use efficiency in soil [27]. Microbial C use efficiency (CUE) can indirectly affect SOC cycling by posing impacts on microbial biomass and necromass [28]. Accordingly, determining soil C-transformation enzyme activity after char amendment is also necessary to better understand SOM decomposition and SOC decomposition [29]. More detailed results and discussion regarding the effects of SPC and SHC on the soil MBC, microbial metabolic quotient, and C-transforming enzyme activity are presented in Text S2, Figures S3, S4. The distribution pattern and stability of aggregates, a basic unit of soil structure, play critical roles in mediating SOC turnover and decomposition [30]. The char-induced alternations in the proportion of soil macroaggregates, microaggregates, and MWD might have been attributed to the mechanical mixing of soil with the applied char, which passed through a 0.45-μm [19, 31]. Due to the high stability (i.e., resistance to abiotic and biotic degradation) of char particles, the weight loss and size decrease of chars in soil aggregate fractions during incubation can be neglected [32, 33]. Therefore, the contribution of char particles to the aggregate proportion and MWD values was calibrated by subtracting the size proportion and MWD values of the SPC and SHC particles from the original experimental data (Figure S5). More detailed calibration methods are given in Text S3. The calibrated distribution patterns and stabilities of the soil aggregates are shown in Figure 2. For the macroaggregates (250–2000 μm) and microaggregates (53–250 μm), SPC and SHC additions increased their proportion compared with CK, following the order of 3%SHC > 1%SHC ≈ 3%SPC > 1%SPC (Figure S6C). Conversely, the proportion of silt–clay fractions (<53 μm) was substantially decreased after 3%SPC, 1%SHC, and 3%SHC amendments (Figure S6A,B), while SHC generally had a greater reduction effect than SPC (Figure S5C). These results demonstrated that SPC and SHC increase the macroaggregate and microaggregate amounts instead of the silt–clay fractions. As for the stability index of soil aggregates, the 3% SPC, 1% SHC, and 3% SHC additions significantly increased the MWD values by 4.26%, 4.67%, and 7.62%, respectively (Figure 1D). Comparably, the soil MWD values were slightly affected by 1% SPC, supporting our hypothesis that SHC posed greater promotional effects on soil aggregation than SPC. These results confirmed that the char-elevated stability of soil aggregates could be attributed to the interactions between char and soil particles instead of the simple mechanical mixing between them. Sporadic studies reported that pyrochar significantly promotes the formation and stability of aggregates in salt-affected soils [32, 33]. Our previous study also demonstrated that corn pyrochars at 350°C and 550°C could enhance the stability of coastal salt-affected soil aggregates resulting from the intimate physicochemical associations between SOM–mineral complex and pyrochar particles [19]. However, only a few studies have declared that pyrochar has little effect on salt-affected soil aggregates [32, 34]. Char-induced alterations in soil aggregation are largely affected by char attributes (application rate, feedstock type, and charring temperature), experimental conditions (land use and field duration), and soil properties (pH, physical texture, and initial SOC content) [35]. For the biochar attributes, the contents of oxygen-containing functional groups (e.g., –COOH and –OH) and polyvalent cations (e.g., Ca2+ and Mg2+), which show high reactivity with soil minerals, mainly determine their effect on salt-affected soil aggregation [8, 31]. Compared with SPC, SHC was enriched in O-containing functional groups (Figure S1) and showed a greater probability of bridging with SOM and minerals to form organic matter–mineral complexes via hydrogen bonding and ligand exchange [31], which consequently showed stronger impacts on soil aggregation. This could explain the greater promotional effect of SHC than that of SPC on the formation of soil macroaggregates and microaggregates (Figure S6A,B). Additionally, char amendments can stimulate the secretion of microbial metabolites such as polysaccharides, amino acids, and organic acids by increasing the availability of soil nutrients and altering rhizosphere soil conditions, thereby increasing the stability of soil aggregates. As a result, the chars produced from mineral-enriched feedstock (e.g., livestock manure and sludge) at a low temperature (<500°C) could have a more favorable influence on improving soil aggregation [32]. However, following char application, the responses of the microbial community and exudated metabolites largely vary, and the roles of char-induced shifts in microbial community structure and metabolic functions and alterations of microbial metabolites in improving the structure and stability of soil aggregates in salt-affected soils are poorly understood [36, 37]. In the present study, SHC contained relatively higher amounts of DOC and dissolved organic nitrogen (DON, 104 vs. 2.42 mg/g, 1.41 vs. 0.13 mg/g, Table S1) could more significantly stimulate the secretion of microbial metabolites through elevating the availability of soil nutrients (e.g., increasing total carbon (TC) and total nitrogen (TN) content in SHC-treated soil than CK) (Figure S3B,C) than SPC, thereby increasing the stability of the soil aggregates [36, 37]. Char amendment can change the microbial community structure and functional response resulting from its impact on substrate availability [20] and soil physicochemical properties (e.g., pH and exchangeable cation capacity) [38], thereby affecting microbially driven SOC decomposition processes. The Chao1, ACE, and Shannon indices were not affected by SPC or SHC amendments, but 3%SHC increased the Simpson index (Table S2), exhibiting the lifted bacterial community diversity following SHC amendments. Keystone ecological clusters of the network for all bacterial taxa at the phylum level were identified (Figure 2A). Four modules and three main network ecological clusters (module #1, 2, and 3) were detected in the bacterial co-occurrence network, Actinobacteria was predominant in module #1, followed by Proteobacteria and Acidobacteria. Proteobacteria was dominant in module #2, followed by Actinobacteria. Actinobacteria was predominant in module #3, followed by Proteobacteria (Figure 2B). The phyla Actinobacteria, Proteobacteria, and Actinobacteria were the keystone nodes of typical ecological clusters. From the principal component analysis (PCA) analysis, SHC displayed different clustering features of the bacterial community compared with CK (Adonis test, p < 0.01). This suggests that the SHC treatment remarkably altered the composition of the soil bacterial community (Figure 2C). Comparably, SPC occupied a similar clustering feature of the bacterial community to that of the CK, implying little impact on the community composition posed by SPC. The effect of char amendment on the bacterial abundance was further investigated (Figure 2D). SPC and SHC amendments increased the relative abundance of dominant bacterial node Proteobacteria by 20.1% and 119%, compared with CK, respectively (Figure 2D). Additionally, SHC increased the relative abundance of Acidobacteria, which are considered soil aggregation-promoting and acid-tolerant bacteria with high polysaccharide and enzyme secreion potential for transport and utilization of carbohydrates relative to CK [39, 40]. This implied that the enhanced soil aggregation in the SHC soils relative to CK (Figure 1D) could be driven by the bacterial responses associated with the transformation and secretion of these cementing agents. Similarly, the relative abundance of Bacteroidetes, copiotrophic bacteria with high turnover rates and activities in the C/N substrate plentiful soils [41], was remarkably increased after SHC amendment relative to CK, possibly resulting from the provision of higher-level labile C substrates and other nutrients (NH4+-N and TN content) in SHC-applied soils than those of SPC (Figure S3). This was consistent with previous studies reporting that the pyrochar-induced shift in microbial communities to copiotrophic taxa was driven by the increased availability of soil organic C substrates [42]. SHC generally increased the abundance of bacterial genera Sphingomona (ligninolysis bacteria) [40, 43], Burkholderia (cellulose hydrolysis bacteria, efficient decomposers of aromatic C) [44], and Bryobacter (active in aromatic hydrocarbon degradation) [45], showing an increasing trend for the degradation potential of polysaccharide-like C substrate after SHC application, consistent with the increased content of humic-like microbially degraded/transformed C products and proteins (C1 and C2) in the SHC-treated soils (Figure S7, S8). The SPC had little influence on the abundance of these bacterial genera (Figure 2E). These differences in bacterial community composition between SPC and SHC were further confirmed by linear discriminant analysis (Figure 2F). At the phylum level, Gemmatimonadota was identified as a discriminating taxon for SPC amendment, while SHC treatment possessed discriminating bacterial phyla Acidobacteria and Proteobacteria. At the class level, Actinobacteria and Alphaproteobacteria were the discriminating bacterial taxa in response to SPC, whereas Bacteroidia was the discriminating bacterial class in response to SHC. SOM humification process was closely related to the microbial transformation of lignin-like and condensed aromatic molecules [46]. Thus, the SHC-triggered microbial function potential toward the efficient transformation of polysaccharide-C/N substrates into highly reactive microbially derived carbohydrates and proteins could potentially promote soil humification and aggregation-mediated soil SOC stabilization. The contributions of influential factors, such as char characteristics, bacterial responses, soil properties, aggregate stability, and DOM composition, to char-induced alterations in SOC decomposition were evaluated by structural equation model (SEM) analysis (Figure 3). The physicochemical properties of SPC-modified soil (decreased soil pH, increased C/N ratios, and TC content) were the greatest contributors to the reduction in SOC decomposition (Figure 3A,B). Comparably, SHC-induced soil C-transformation bacterial modulation predominantly contributed to decreased salt-affected SOC decomposition (negative priming effects), followed by promoted soil aggregation and altered DOM composition (Figure 3C,D), clearly demonstrating the significant roles of SHC-triggered bacterial modulation in affecting SOC decomposition, distinct from the SPC-constructed models (Figure 3A,B). However, SHC characteristics (mainly pH and DOC content) were the greatest direct and positive contributors to decreased SOC decomposition, supported by the significant positive correlations between SHC and SOC. These results support our hypothesis that SHC induces the greater negative priming effect of SOC decomposition than SPC by shifting the microbial composition and promoting soil aggregation rather than the direct action of SHC itself as an exogenous C substrate in soils [19, 20]. Moreover, SHC-promoted soil aggregation, one of the most important factors in SOC decomposition, was directly affected by the combined action of SHC and bacterial modulation of C transformation. This explains why the remarkably enhanced soil aggregation in the SHC soils was driven by the C-transformation bacterial responses associated with increased SOM humification and generation of highly reactive metabolites (e.g., polysaccharides and organic acids) for the formation and stabilization of soil aggregates (Figure 1D). In addition, the SHC-modulated C-transformation bacterial response was significantly affected by soil properties (i.e., pH, soil C/N ratio, and TC content), which are conducive to SOC decomposition. This verified that SHC could induce bacterial responses involved in C transformation by altering soil conditions such as substance availability and salt stress, consistent with previous findings [22, 47]. Therefore, the key environmental factors shifting the composition of the soil bacterial community were further identified using RDA (Figure S9). The results showed that soil pH, regarded as a critical environmental factor regulating soil C cycles, microbial community composition, and metabolic potential [22, 47], mainly drove the shift in bacterial community composition. It was reported that hydrochars produced from poplar wood dust and wheat straw decreased the diversity of bacterial communities in paddy soils [15]. The authors attributed this to the fact that acidic soil conditions altered by hydrochars are not best suited for bacterial species that are favored under neutral conditions. However, in the present study, the acidic hydrochar (pH 4.15) (Table S1) lowered the soil pH from alkaline to neutral (Figure S3D). Therefore, the improved habitats for microbes by SHC may account for the shift in soil bacterial responses. SHC characteristics (pH and DOC content) had a nonsignificant direct effect on soil dissolved organic matter (DOM) composition, implying that the alterations of DOM composition in SHC soils could not be primarily a result of the incorporation of the labile C component from SHC (Figure 3C). This was supported by the small effect of SHC on soil DOC content relative to CK (Figure S3A). Conversely, poplar wood dust and wheat SHC decreased the labile SOC fraction and increased the stable SOC fraction in paddy soil [22]. The authors ascribed the results to the hydrochar-induced changes in the structural composition of bacterial communities, that is, reduced abundance of the condensed aromatic C degrader Sphingobacterium and increased abundance of bacterial decomposers of labile SOC. However, in the present study, the C-transformation bacterial response did not contribute (non-significant correlations) to soil DOM alterations, as revealed by the SEM models (Figure 3C). These differences could be explained by the different SOC stabilization pathways or statuses of the two tested soils. For instance, the short-term promotional effects on microbial-mediated C transformation after the application of hydrochar with high decomposability may not be apparent in clayed salt-affected soils, where most C is chemically associated with minerals [48]. Collectively, the negative priming effects on SOC decomposition in the SHC-amended soil were primarily driven by bacterial modulation and enhanced soil aggregation. Comparably, the modification of soil properties (e.g., decreased pH and increased C/N ratio) mainly accounted for the decrease in SOC decomposition in the SPC-treated soils. The results demonstrated that SHC induced greater negative priming effects of SOC decomposition (35.2%–80.0% vs. 10.5%–31.5%) than those of SPC. SHC-enhanced soil aggregate stability and humification process of SOM and increased abundance of bacterial taxa participated in the efficient transformation of condensed aromatic molecules into humic-like substances were the underlying mechanisms. These findings provide novel insights into the potential roles of hydrochar in affecting the C biogeochemical cycle of salt-affected soils and the basis for the development of robust measures to elevate the soil C sequestration potential of blue C ecosystems. Xiao Wang designed the research. Zhen Li performed the research. Yadong Cheng and Hui Yao conducted data analysis. Xiao Wang wrote and edited the manuscript. Hui Li, Xiangwei You, Chengsheng Zhang, and Yiqiang Li edited the manuscript. All authors have commented on and approved the final manuscript. This work was funded by the Youth innovation of Chinese Academy of Agricultural Sciences (Y2023QC35), the Shandong Provincial Natural Science Foundation (ZR2021QD083), the Agricultural Science and Technology Innovation Program of China (ASTIP-TRIC06, ASTIP No. CAASZDRW202201), and the Central Public-interest Scientific Institution Basal Research Fund (No.1610232023019). The authors declare no conflict of interest. New sequencing data was used in this article. The 16S rRNA gene amplicon was uploaded to NCBI under the accession number SRR25706658 (https://www.ncbi.nlm.nih.gov/sra/PRJNA1007573). Detailed information on the analysis process of bacterial 16S rRNA gene amplification [49] and co-occurrence bacterial network construction [50] are given in Supporting Information. Supporting Information (figures, tables, scripts, graphical abstract, slides, videos, Chinese translated version, and update materials) may be found in the online DOI or iMeta Science http://www.imeta.science/. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.}, number={4}, journal={IMETA}, author={Wang, Xiao and Li, Zhen and Cheng, Yadong and Yao, Hui and Li, Hui and You, Xiangwei and Zhang, Chengsheng and Li, Yiqiang}, year={2023}, month={Nov} }
 @article{cheng_wang_zhao_zhang_kong_li_you_li_2023, title={Wheat straw pyrochar more efficiently decreased enantioselective uptake of dinotefuran by lettuce and dissemination of antibiotic resistance genes than hydrochar in an agricultural soil}, volume={880}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2023.163088}, abstractNote={Remediation of soils pollution caused by dinotefuran, a chiral pesticide, is indispensable for ensuring human food security. In comparison with pyrochar, the effect of hydrochar on enantioselective fate of dinotefuran, and antibiotic resistance genes (ARGs) profiles in the contaminated soils remain poorly understood. Therefore, wheat straw hydrochar (SHC) and pyrochar (SPC) were prepared at 220 and 500 °C, respectively, to investigate their effects and underlying mechanisms on enantioselective fate of dinotefuran enantiomers and metabolites, and soil ARG abundance in soil-plant ecosystems using a 30-day pot experiment planted with lettuce. SPC showed a greater reduction effect on the accumulation of R- and S-dinotefuran and metabolites in lettuce shoots than SHC. This was mainly resulted from the lowered soil bioavailability of R- and S-dinotefuran due to adsorption/immobilization by chars, together with the char-enhanced pesticide-degrading bacteria resulted from increased soil pH and organic matter content. Both SPC and SHC efficiently reduced ARG levels in soils, owing to lowered abundance of ARG-carrying bacteria and declined horizontal gene transfer induced by decreased dinotefuran bioavailability. The above results provide new insights for optimizing char-based sustainable technologies to mitigate pollution of dinotefuran and spread of ARGs in agroecosystems.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Cheng, Yadong and Wang, Xiao and Zhao, Liuwei and Zhang, Xin and Kong, Qingxian and Li, Hui and You, Xiangwei and Li, Yiqiang}, year={2023}, month={Jul} }
 @article{yan_li_zhu_peacock_liu_li_zhang_hong_liu_yin_2023, title={Zinc Stable Isotope Fractionation Mechanisms during Adsorption on and Substitution in Iron (Hydr)oxides}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.2c08028}, abstractNote={The Zn isotope fingerprint is widely used as a proxy of various environmental geochemical processes, so it is crucial to determine which are the mechanisms responsible for isotopic fractionation. Iron (Fe) (hydr)oxides greatly control the cycling and fate and thus isotope fractionation factors of Zn in terrestrial environments. Here, Zn isotope fractionation and related mechanisms during adsorption on and substitution in three FeOOH polymorphs are explored. Results demonstrate that heavy Zn isotopes are preferentially enriched onto solids, with almost similar isotopic offsets (Δ66/64Znsolid-solution = 0.25-0.36‰) for goethite, lepidocrocite, and feroxyhyte. This is consistent with the same average Zn-O bond lengths for adsorbed Zn on these solids as revealed by Zn K-edge X-ray absorption fine structure spectroscopy. In contrast, at an initial Zn/Fe molar ratio of 0.02, incorporation of Zn into goethite and lepidocrocite by substituting for lattice Fe preferentially sequesters light Zn isotopes with Δ66/64Znsubstituted-stock solution of -1.52 ± 0.09‰ and -1.18 ± 0.15‰, while Zn-substituted feroxyhyte (0.06 ± 0.11‰) indicates almost no isotope fractionation. This is closely related to the different crystal nucleation and growth rates during the Zn-doped FeOOH formation processes. These results provide direct experimental evidence of incorporation of isotopically light Zn into Fe (hydr)oxides and improve our understanding of Zn isotope fractionation mechanisms during mineral-solution interface processes.}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Yan, Xinran and Li, Wei and Zhu, Chuanwei and Peacock, Caroline L. and Liu, Yizhang and Li, Hui and Zhang, Jing and Hong, Mei and Liu, Fan and Yin, Hui}, year={2023}, month={Apr} }
 @article{yin_suo_zheng_you_li_wang_zhang_li_cheng_2022, title={Biochar-compost amendment enhanced sorghum growth and yield by improving soil physicochemical properties and shifting soil bacterial community in a coastal soil}, volume={10}, ISSN={["2296-665X"]}, DOI={10.3389/fenvs.2022.1036837}, abstractNote={Soil salinization, an important type of soil degradation, has become a problem restricting crop production and food quality. The remediation technologies by using compost and biochar were considered sustainable and environment friendly, but the sole application of compost or biochar hardly gets the satisfactory remediation effects. Until now, information about the effects of cocomposted biochar on soils is limited, especially in the coastal soil. This study investigated the impact and potential underlying mechanism of corn straw biochar (BC), seaweed compost (SC), and cocomposted BC and SC (BCSC) on the growth and yield of sorghum (Sorghum bicolor (L.) Moench) in the coastal soil of China in a pot experiment. BC and BCSC treatments increased the dry biomass and yield of the sorghum by 44.0–52.4% and 132.9–192.3%, respectively. Similarly, the root morphologies of sorghum, including surface area and average diameter, were also increased with BC and BCSC addition. Meanwhile, BCSC treatment showed a better performance than what the others did. The enhanced growth and yield of sorghum primarily resulted from the improvement of soil properties (WHC, SOM, and EC) and nutrient availability (Olsen-P and AK content). In addition, the increased diversity and shifted composition of soil bacteria with BC and BCSC addition might also account for the increased growth and yield of sorghum. Furthermore, the enhanced relative abundances of beneficial bacteria Vicinamibacteraceae (39.0%) and Sphingomonadaceae (41.5%) in the rhizosphere soil were positively correlated with the content of available nutrients (NH4+, Olsen-P, and available K) in the coastal soil, which might reveal the mechanism of enhancing growth under the established collaborative interactions of them. Our study provides the potential of using biochar-compost to ameliorate the degradation of coastal soils and improve crop yield.}, journal={FRONTIERS IN ENVIRONMENTAL SCIENCE}, author={Yin, Shaojing and Suo, Fengyue and Zheng, Ying and You, Xiangwei and Li, Hui and Wang, Juying and Zhang, Chengsheng and Li, Yiqiang and Cheng, Yadong}, year={2022}, month={Nov} }
 @article{li_reinhart_moller_herndon_2022, title={Effects of C/Mn Ratios on the Sorption and Oxidative Degradation of Small Organic Molecules on Mn-Oxides}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.2c03633}, abstractNote={Manganese (Mn) oxides have a high surface area and redox potential that facilitate sorption and/or oxidation of organic carbon (OC), but their role in regulating soil C storage is relatively unexplored. Small OC compounds with distinct structures were reacted with Mn(III/IV)-oxides to investigate the effects of OC/Mn molar ratios on Mn-OC interaction mechanisms. Dissolved and solid-phase OC and Mn were measured to quantify the OC sorption to and/or the redox reaction with Mn-oxides. Mineral transformation was evaluated using X-ray diffraction and X-ray absorption spectroscopy. Higher OC/Mn ratios resulted in higher sorption and/or redox transformation; however, interaction mechanisms differed at low or high OC/Mn ratios for some OC. Citrate, pyruvate, ascorbate, and catechol induced Mn-oxide dissolution. The average oxidation state of Mn in the solid phase did not change during the reaction with citrate, suggesting ligand-promoted mineral dissolution, but decreased significantly during reactions with the other compounds, suggesting reductive dissolution mechanisms. Phthalate primarily sorbed on Mn-oxides with no detectable formation of redox products. Mn-OC interactions led primarily to C loss through OC oxidation into inorganic C, except phthalate, which was predominantly immobilized in the solid phase. Together, these results provided detailed fundamental insights into reactions happening at organo-mineral interfaces in soils.}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Li, Hui and Reinhart, Benjamin and Moller, Spencer and Herndon, Elizabeth}, year={2022}, month={Dec} }
 @article{zhang_li_wu_post_lanson_liu_hu_wang_zhang_hong_et al._2022, title={Effects of cobalt doping on the reactivity of hausmannite for As(III) oxidation and As(V) adsorption}, volume={122}, ISSN={["1878-7320"]}, DOI={10.1016/j.jes.2022.02.0041001-0742}, journal={JOURNAL OF ENVIRONMENTAL SCIENCES}, author={Zhang, Shuang and Li, Hui and Wu, Zhongkuan and Post, Jeffrey E. and Lanson, Bruno and Liu, Yurong and Hu, Biyun and Wang, Mingxia and Zhang, Limei and Hong, Mei and et al.}, year={2022}, month={Dec}, pages={217–226} }
 @article{zhang_li_wu_post_lanson_liu_hu_wang_zhang_hong_et al._2022, title={Effects of cobalt doping on the reactivity of hausmannite for As(III) oxidation and As(V) adsorption}, volume={122}, ISSN={["1878-7320"]}, DOI={10.1016/j.jes.2022.02.004}, abstractNote={Hausmannite is a common low valence Mn oxide mineral, with a distorted spinel structure, in surficial sediments. Although natural Mn oxides often contain various impurities of transitional metals (TMs), few studies have addressed the effect and related mechanism of TM doping on the reactivity of hausmannite with metal pollutants. Here, the reactivity of cobalt (Co) doped hausmannite with aqueous As(III) and As(V) was studied. Co doping decreased the point of zero charge of hausmannite and its adsorption capacity for As(V). Despite a reduction of the initial As(III) oxidation rate, Co-doped hausmannite could effectively oxidize As(III) to As(V), followed by the adsorption and fixation of a large amount of As(V) on the mineral surface. Arsenic K-edge EXAFS analysis of the samples after As(V) adsorption and As(III) oxidation revealed that only As(V) was adsorbed on the mineral surface, with an average As-Mn distance of 3.25-3.30 Å, indicating the formation of bidentate binuclear complexes. These results provide new insights into the interaction mechanism between TMs and low valence Mn oxides and their effect on the geochemical behaviors of metal pollutants.}, journal={JOURNAL OF ENVIRONMENTAL SCIENCES}, author={Zhang, Shuang and Li, Hui and Wu, Zhongkuan and Post, Jeffrey E. and Lanson, Bruno and Liu, Yurong and Hu, Biyun and Wang, Mingxia and Zhang, Limei and Hong, Mei and et al.}, year={2022}, month={Dec}, pages={217–226} }
 @article{zhao_tan_li_wang_yao_liu_liu_2022, title={Multi-walled Carbon Nanotubes Remediate the Phytotoxicity of Quinclorac to Tomato}, ISSN={["1432-0800"]}, DOI={10.1007/s00128-022-03582-8}, abstractNote={In order to remediate the phytotoxicity of quinclorac to tomato by multi-walled carbon nanotubes (MWCNTs), the adsorption of quinclorac to MWCNTs was monitored and the effect of MWCNTs on the phytotoxicity of quinclorac to tomato in soil were studied. The results showed that the Linear equation and Freundlich equation can well fit the adsorption isotherm of quinclorac in the soil containing MWCNTs. The adsorption of quinclorac in soil was significantly enhanced by the addition of MWCNTs; the K d  of soil (1% MWCNTs) was 28.7 times of pure soil. The quinclorac had an obvious inhibitory effect on the growth of tomatoes; serious phytotoxicity was also induced even at the lowest concentration of 0.025 mg/kg. With the MWCNTs content in soil increased to 0.5% and 1%, the phytotoxicity of quinclorac to tomatoes decreased significantly, and the height and fresh weight of tomatoes were even higher than those of the control group, indicating that MWCNTs can promote the growth of tomato. These results provide a reference for resolving the problem of phytotoxicity induced by residual herbicides in farmland.}, journal={BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY}, author={Zhao, Jingyu and Tan, Shuo and Li, Hui and Wang, Yao and Yao, Ting and Liu, Lejun and Liu, Kailin}, year={2022}, month={Jul} }
 @article{zhao_song_li_zheng_li_liu_li_bai_liu_2022, title={New Formulation to Accelerate the Degradation of Pesticide Residues: Composite Nanoparticles of Imidacloprid and 24-Epibrassinolide}, volume={7}, ISSN={["2470-1343"]}, DOI={10.1021/acsomega.2c02820}, abstractNote={Pest control effectiveness and residues of pesticides are contradictory concerns in agriculture and environmental conservation. On the premise of not affecting the insecticidal effect, the pesticide residues in the later stage should be degraded as fast as possible. In the present study, composite nanoparticles in a double-layer structure, consisting of imidacloprid (IMI) in the outer layer and plant hormone 24-epibrassinolide (24-EBL) in the inner layer, were prepared by the W/O/W solvent evaporation method using Eudragit RL/RS and polyhydroxyalkanoate as wall materials. The release of IMI in the outer layer was faster and reached the maximum within 24 h, while the release of 24-EBL in the inner layer was slower and reached the maximum within 96 h. The contact angle of the composite nanoparticles was half that of the 5% IMI emulsifiable concentrate (EC), and the deposition of composite nanoparticles on rice was twice that of 5% IMI EC, which increased the pesticide utilization efficiency. Compared with the common pesticide, 5% IMI EC, the insecticidal effect of the composite nanoparticles was stronger than that of planthoppers, with a much lower final residue amount on rice after 21 days. The composite nanoparticles prepared in this study to achieve sustained release of pesticides and, meanwhile, accelerate the degradation of pesticide residues have a strong application potential in agriculture for controlling pests and promoting crop growth.}, number={33}, journal={ACS OMEGA}, author={Zhao, Jingyu and Song, Rong and Li, Hui and Zheng, Qianqi and Li, Shaomei and Liu, Lejun and Li, Xiaogang and Bai, Lianyang and Liu, Kailin}, year={2022}, month={Aug}, pages={29027–29037} }
 @article{shao_liu_li_luo_zhao_liu_yan_wang_luo_liu_et al._2022, title={The effects of polyethersulfone and Nylon 6 micromembrane filters on the pyraclostrobin detection: adsorption performance and mechanism}, ISSN={["1614-7499"]}, DOI={10.1007/s11356-022-21021-3}, abstractNote={Adsorption of test substances on micromembrane filters during sample pretreatment before qualitative and quantitative analysis has greatly affected the accuracy of the measurement. In the present study, it was found that the adsorption rate of pyraclostrobin reached 77.7-100% when water samples of pyraclostrobin (1 mL) were filtered with polyethersulfone (PES) and Nylon 6 filters. Therefore, the adsorption mechanisms were investigated from the kinetics, isotherms, and thermodynamics of the pyraclostrobin adsorption process, combined with attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis. The results showed that PES accorded with second-order adsorption kinetics and Nylon 6 with first-order adsorption kinetics, and the correlation coefficient R 2  was 0.98. The adsorption behavior of the two micromembranes followed the linear isothermal model, indicating that the adsorption process was through monolayer adsorption. Thermodynamic study showed that the adsorption of pyracoethyl on PES membrane was spontaneous endothermic, while that on Nylon 6 was spontaneous exothermic. The π-π electron-donor-acceptor (EDA) between pyraclostrobin and PES may promote the adsorption of PES to pyraclostrobin, and hydrogen bonding between pyraclostrobin and Nylon 6 micromembrane may be involved in the adsorption. Our study also proved that the adding 60% methanol and iodine solution (2 mmol/L) was an effective strategy to reduce the adsorption effects and to increase the accuracy of the detection.}, journal={ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH}, author={Shao, Xiaolan and Liu, Lejun and Li, Hui and Luo, Yue and Zhao, Jingyu and Liu, Shuai and Yan, Bei and Wang, Dan and Luo, Kun and Liu, Min and et al.}, year={2022}, month={May} }