通讯机构：
[Lin Tang; Yaocheng Deng; Lin Tang Lin Tang Lin Tang; Yaocheng Deng Yaocheng Deng Yaocheng Deng] C;College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082 P. R. China<&wdkj&>College of Resources & Environment, Hunan Agricultural University, Changsha, Hunan, 410128 P. R. China
摘要：
A novel C‐TiO2/PCN (CNT) composite is designed for piezo‐photocatalytic ciprofloxacin (CIP) degradation. The twisty structure, n→π* electronic transition, and Step‐scheme heterojunction of CNT can respectively give rise to the promotion of piezoelectricity, light utilization, and charge separation, leading to much more efficient CIP degradation during the piezo‐photocatalysis than individual photocatalysis or piezocatalysis. Abstract Herein, a twisty C‐TiO2/PCN (CNT) Step‐scheme (S‐scheme) heterojunction is fabricated and applied to degrade ciprofloxacin (CIP) with the assistance of ultrasonic vibration and visible light irradiation. The nitrogen‐rich twisty polymeric carbon nitride (PCN) can not only induce a non‐centrosymmetric structure with enhanced polarity for a better piezoelectric effect but also provide abundant lone pair electrons to promote n→π* transition during photocatalysis. Its hybridization with C‐TiO2 particles can construct S‐scheme heterojunction in CNT. During the piezo‐photocatalysis, the strain‐induced polarization electric field in the heterojunction can regulate the electron migration between the two components, resulting in a more effective CIP degradation. With the synergistic effect of ultrasonic vibration and visible light irradiation, the reaction rate constant of CIP degradation by CNT increases to 0.0517 min−1, which is 1.86 times that of photocatalysis and 6.46 times that of ultrasound. This system exhibits a stable CIP decomposition efficiency under the interference of various environmental factors. In addition, the in‐depth investigation found that three pathways and 12 major intermediates with reduced toxicity are produced after the reaction. Hopefully, the construction of this twisty CNT S‐scheme heterojunction with enhanced piezo‐photocatalytic effect offers inspiration for the design of environmentally functional materials.
摘要：
Biochar derived from bamboo was used to support sulfide nanoscale zero-valent iron (S-nZVI@BC) for simultaneous removal of Cd(II) and As (III) from aqueous media. Scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD) characterization confirmed the successful synthesis of the S-nZVI@BC. Adsorption kinetics and isotherms indicated that co-adsorption of Cd(II) and As(III) onto S-nZVI@BC was well represented by pseudo-second-order model (R(2)(Cd(II))=0.990, R(2)(As(III))=0.995) and Langmuir model (R(2)(Cd(II))=0.954, R(2)(As(III))=0.936). The maximum adsorption was 162.365 and 276.133mg/g for Cd(II) and As(III), respectively, in a co-adsorption system, which was significantly higher than that in a single adsorption system (103.195 and 223.736mg/g, respectively). Batch experiments showed that the Cd(II)-to-As(III) concentration ratio significantly affected the co-adsorption with the optimal ratio of 1:2. Ca(2+) and Mg(2+) significantly inhibited Cd(II) removal. In contrast, phosphate and humic acid significantly inhibited As(III) removal. Electrochemical analysis indicated S-nZVI@BC had a lower corrosion potential and resistance than nZVI@BC, making it more conducive to electron transfer and chemical reaction. Electrostatic adsorption, complexation, co-precipitation, and redox were the primary mechanisms for Cd(II) and As(III) removal. Overall, the present study provides new insights into the synergistic removal of Cd(II) and As(III) by S-nZVI@BC, which is a very promising adsorbent for the effective removal of Cd(II) and As(III) from contaminated wastewater.
通讯机构：
[Tiean Zhou; Tiean Zhou Tiean Zhou Tiean Zhou] C;[Linhong Deng; Linhong Deng Linhong Deng Linhong Deng] H;Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha, Hunan, 410128 China<&wdkj&>Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu, 213164 China<&wdkj&>College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, Hunan, 410128 China<&wdkj&>Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha, Hunan, 410128 China
摘要：
Double resonator piezoelectric cytometry (DRPC) is developed to simultaneously quantify cells’ generated forces ΔS and viscoelastic moduli G′, G″ of a population of isolated single cells or cells with different cell‐cell contacts adhered to the AT and BT cut quartz crystals of the same frequency and morphology by measuring their respective changes in resonant frequency and motional resistance. Abstract Cell mechanics is closely associated with cellular structure and function. However, the inability to measure both cellular force and viscoelasticity of statistically significant number of cells noninvasively remains a challenge for quantitative characterizations of various cellular functions and practical applications. Here a double resonator piezoelectric cytometry (DRPC), using AT and BT cut quartz crystals of the same frequency and surface morphology is developed to simultaneously quantify the cells‐generated forces (ΔS) and viscoelastic moduli (G′, G″) of a population of isolated single cells or cells with different degrees of cell‐cell interactions in a non‐invasive and real time manner. DRPC captures the dynamic mechanical parameters ΔS and G′, G″ during the adhesions of human umbilical vein endothelial cells (HUVECs) under different ligand densities of adhesion molecules fibronectin or Arg‐Gly‐Asp (RGD) modified on the gold surfaces of 9 MHz AT and BT cut quartz crystals, and different seeding densities of HUVECs. It is found that both the ligand density and cell seeding density affect the magnitudes of ΔS and G′, G″ and their correlations are revealed for the first time by DRPC. The validity of DRPC is further verified by mechanical changes of the cells in response to treatments with cytoskeleton regulators.
作者机构：
[陈香碧; 吴金水; 毛婉琼; 苏以荣; 马冲] Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China;[毛婉琼; 马冲] University of Chinese Academy of Sciences, Beijing 100049, China;[夏银行] College of Resource and Environment, Hunan Agricultural University, Changsha 410128, China;[朱光旭] College of Biology and Environment Engineering, Guiyang University, Guiyang 550005, China;[王忠诚] College of Forestry, Central South University of Forestry & Technology, Changsha 410004, China
摘要：
A strain of Enterobacter was screened from cadmium and arsenic contaminated farmland soil and its passivation mechanism of cadmium and arsenic were explored through removing performance and characterization experiments. The results showed that the screened strain M5 was identified as Enterobacter sp. with a sulfate-reduction function, and its maximum resistance concentration was approximately 1 mmol·L(-1) to cadmium and arsenic. In the simulation system, the maximum removal efficiencies of cadmium and arsenic were 94.13% and 27.26% by strain M5, respectively. The results of SEM-EDS and XRD confirmed that Cd and As were fixed to CdS and As(2)S(3), and XPS results showed that carboxyl groups, hydroxyl groups, and amide groups on the surface of the bacteria were mainly involved in biological adsorption. These results can provide new ideas and a theoretical basis for microbial applications to soil remediations for heavy metal pollution.
期刊：
Journal of Environmental Management,2023年345:118451 ISSN：0301-4797
通讯作者：
Zou, Yeai;Xie, YH;Zou, Y
作者机构：
[Deng, Zhengmiao; Xie, Yonghong; Zou, Yeai; Li, Feng; Zhang, Pingyang] Chinese Acad Sci, Key Lab Agroecol Proc Subtrop Reg, Changsha 410125, Peoples R China.;[Deng, Zhengmiao; Xie, Yonghong; Zhang, Siqi; Zou, Yeai; Li, Feng; Zhang, Pingyang] Chinese Acad Sci, Inst Subtrop Agr, Dongting Lake Stn Wetland Ecosyst Res, Changsha 410125, Peoples R China.;[Zhang, Siqi] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Wu, Ting] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Peoples R China.;[Zhang, Hong] Forestry Bur Yueyang, Yueyang 414000, Peoples R China.
通讯机构：
[Xie, YH ; Zou, Y; Zou, Y ] C;Chinese Acad Sci, Key Lab Agroecol Proc Subtrop Reg, Changsha 410125, Peoples R China.;Chinese Acad Sci, Inst Subtrop Agr, Dongting Lake Stn Wetland Ecosyst Res, Changsha 410125, Peoples R China.;Chinese Acad Sci, Inst Subtrop Agr, 644, Yuanda Second Rd, Changsha 410125, Peoples R China.
关键词：
Dongting lake;Habitat suitability;Hydrological change;Species distribution model;Wetland management
摘要：
The operation of the Three Gorges Project (TGP) has influenced the wetland ecosystems downstream, thereby affecting the distribution of habitats suitable for waterbirds. However, dynamic studies on habitat distribution under different water regimes are lacking. Here, using data from three successive wintering periods representing three typical water regimes, we modelled and mapped the habitat suitability of three waterbird groups in Dongting Lake, which is the first river-connected lake downstream of the TGP, and a crucial wintering ground for waterbirds along the East Asian-Australasian Flyway. The results showed that the spatial pattern of habitat suitability varied among the wintering periods and waterbird groups. The analysis estimated the largest suitable habitat area for the herbivorous/tuber-eating group (HTG) and the insectivorous waterbird group (ING) under a normal water recession pattern, whereas early water recession had a more adverse effect. The suitable habitat area for the piscivorous/omnivorous group (POG) was higher under late water recession than under normal conditions. The ING was the most affected by hydrological changes among the three waterbird groups. Further, we identified the key conservation and potential restoration habitats. The HTG exhibited the largest key con-servation habitat area compared to the other two groups, while the ING showed a potential restoration habitat area larger than its key conservation habitat area, indicating its sensitivity to environmental changes. The optimal inundation durations from September 1 to January 20 for HTG, ING and POG were 52 & PLUSMN; 7 d, 68 & PLUSMN; 18 d, and 132 & PLUSMN; 22 d, respectively. Therefore, the water recession starting in mid-October may be favourable for waterbirds in Dongting Lake. Altogether, our results can be used as guidance for prioritising certain management actions for waterbird conservation. Moreover, our study highlighted the importance of considering habitat spatiotemporal variation in highly dynamic wetlands when implementing management practices.
通讯机构：
[Yaocheng Deng; Ying Huang] N;National Engineering Laboratory of High Efficient Use on Soil and Fertilizer, College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
关键词：
Heavy metals;Meta-analysis;Monte Carlo;PM10;PM2.5;Risk assessment
摘要：
In recent decades, China has devoted significant attention to the heavy metals pollution in particulate matter. However, the majority of studies have only focused on the field monitoring in relatively remote areas, which may not be representative of air quality across the country. This study reevaluated the characteristics, temporal and spatial changes, and health concerns associated with heavy metal pollution in atmospheric particulates on a national scale by coupling Meta-analysis and Monte Carlo simulation analysis. In terms of spatial distribution, the heavy metals pollution levels in the northern coast and northeastern regions are relatively high, whereas it is low along the middle Yellow River, middle Yangtze River, as well as Southwest. With the exception of Cu, the distribution of all elements in PM2.5 steadily decreased over time Moreover, PM10 and PM2.5 performed similar where Cd and Ni both first increased followed by a decline while, Cr displayed a decrease before it showed an increment. And since the implementation of prevention and control policies about the atmospheric release, the focus of industrial emission has gradually shifted from energy production and processing to living products manufacturing. Moreover, the carcinogenic risk was shown to be Cr > As, Pb > Ni, Cd, while the non-carcinogenic risk was as follows: As, Ni > Cr, Cd. Among all contaminants, Cd, As, and Cr in PM2.5 and PM10 exceeded the WHO standard in the cities with worst air quality. It was observed that As posed the largest non-carcinogenic risk to adults while, Cr caused the most carcinogenic risk to adults and children, where the carcinogenic risk of children remains higher than that of adults. Therefore, the findings of this study may offer data support to the China's heavy metal pollution standards in airborne particles and offer theoretical data support for pollution management.
通讯机构：
[Guixiang Yuan] H;[Wei Li] R;Hunan Provincial Key Laboratory of Rural Ecosystem Health in Dongting Lake Area, Ecology Department, College of Resources and Environment, Hunan Agricultural University, Changsha, China<&wdkj&>Research Institute of Ecology & Environmental Sciences, Nanchang Institute of Technology, Nanchang, 330099, China
摘要：
Extreme precipitation events caused by climate change leads to large variation of nitrogen input to aquatic ecosystems. Our previous study demonstrated the significant effect of different ammonium pulse patterns (differing in magnitude and frequency) on submersed macrophyte growth based on six plant morphological traits. However, how connectivity among plant traits responds to nitrogen pulse changes, which in turn affects plant performance, has not yet been fully elucidated. The response of three common submersed macrophytes (Myriophyllum spicatum, Vallisneria natans and Potamogeton maackianus) to three ammonium pulse patterns was tested using plant trait network (PTN) analysis based on 18 measured physiological and morphological traits. We found that ammonium pulses enhanced trait connectivity in PTN, which may enable plants to assimilate ammonium and/or mitigate ammonium toxicity. Large input pulses with low frequency had stronger effects on PTNs compared to low input pulses with high frequency. Due to the cumulative and time-lagged effect of the plant response to the ammonium pulse, there was a profound and prolonged effect on plant performance after the release of the pulse. The highly connected traits in PTN were those related to biomass allocation (e.g., plant biomass, stem ratio, leaf ratio and ramet number) rather than physiological traits, while phenotype-related traits (e.g., plant height, root length and AB ratio) and energy storage-related traits (e.g., stem starch) were least connected. V. natans showed clear functional divergence among traits, making it more flexible to cope with unfavorable habitats (i.e., high input pulses with low frequencies). M. spicatum with high RGR revealed strong correlations among traits and thus supported nitrogen accumulation from favourable environments (i.e., low input pulses with high frequencies). Our study highlights the responses of PTN for submerged macrophytes to ammonium pulses depends on their intrinsic metabolic rates, the magnitude, frequency and duration of the pulses, and our results contribute to the understanding of the impact of resource pulses on the population dynamics of submersed macrophytes within the context of global climate change.
摘要：
To reduce the consumption of oxidant and catalyst in Fenton-like reaction and to realize the reuse of catalyst, yeast supported iron nanoparticles (nZVI@SC(M)) was synthesized by tobacco leaf extract and applied in the heterogeneous Fenton-like degradation of aqueous methylene blue (MB) at ambient conditions. The performance of the composite was exploited in terms of catalytic activity and factors influencing MB degradation. The surface changes of nZVI@SC(M) before and after reaction were characterized by XPS, SEM, FT-IR and XRD. Iron leaching, primary reactive oxidizing species, and the storage stability and reusability of catalyst were also investigated. Typically, 99.7% removal of 50mg/L MB, with a TOC removal of 97.2%, could be achieved within 10h by 0.1g/L nZVI@SC(M) coupled with 1.0mMH(2)O(2). The MB degradation is in good agreement with the pseudo-first-order model, and hydroxyl radicals in the bulk solution is the main reactive oxidizing species responsible for MB degradation. Based on the identified intermediates by liquid chromatography/mass spectrometry, the possible MB degradation mechanism in the nZVI@SC(M)/H(2)O(2) system is discussed. The developed high-performance nZVI@SC(M) catalyst strategy can provide a new route in enhancing the Fenton-like degradation of organic contaminants with less consumption of catalyst and oxidant.
摘要：
Abundant evidence has demonstrated the feasibility of reducing phosphorus (P) input to face diminishing phosphate rock resources and deteriorating environmental quality in double-cropping paddy. However, the sustainability of reduced P input in the context of maintaining productivity and P efficient utilization is not yet clear. Herein, an 8-year (2013-2021) field-based database was built to explore the effects of reduced P input on rice productivity and the soil-plant P trade-off in double-cropping paddy. In the early and late rice seasons, compared with conventional P fertilization (early rice, 90 kg hm(-2); late rice, 60 kg hm(-2)), the average yield of reduced 10 % P treatment increased by 4.3 % and 2.1 %, respectively; reduced 10-30 % P treatments increased average P use efficiency by 17.1-18.4 % and 14.0-17.2 %, decreased average total P runoff loss by 14.9-33.2 % and 20.8-36.4 %, and decreased average total P leaching loss by 18.5-49.0 % and 24.0-46.1 %, respectively. Compared with conventional fertilization, reduced P fertilizer input by 10 % significantly increased the content of the soil labile-P fraction while reducing that of the soil stable-P fraction. Soil ligand-P and exchangeable-P content decreased with the gradient reduction of P fertilizer input (10-30 %). The main predictors of the change in rice yield and plant P uptake were soil ligand-P and exchangeable-P content, respectively. The dominant predictor of both the P runoff loss and the P activation coefficient was the inorganic P content extracted by NaHCO(3). These findings suggest that reduced P input by 10 % could maintain rice productivity and P use efficiency in the double-cropping paddy, and the transformations between soil P components and increases in P bioavailability may be the key drivers maintaining rice productivity and P utilization under the context of reduced P loading.
作者机构：
[Sun, Zhanxue; Hu, Zhongqiang; Yu, Xiaoxia; Zhou, Yaoyu; Zhou, Zhongkui; Liu, Yong; Guo, Jianping] East China Univ Technol, State Key Lab Nucl Resources & Environm, Nanchang 330013, Jiangxi, Peoples R China.;[Sun, Zhanxue; Hu, Zhongqiang; Yu, Xiaoxia; Zhou, Yaoyu; Zhou, Zhongkui; Liu, Yong; Guo, Jianping] East China Univ Technol, Sch Water Resources & Environm Engn, Nanchang 330013, Jiangxi, Peoples R China.;[Zhou, Yaoyu] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Peoples R China.;[Zheng, Lili] Univ Sci & Technol Beijing, Sch Energy & Environm Engn, Beijing 100083, Peoples R China.;[Yang, Zhihui] Cent South Univ, Sch Met & Environm, Changsha 410083, Hunan, Peoples R China.
通讯机构：
[Zhongkui Zhou; Yaoyu Zhou] S;State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, Jiangxi, China<&wdkj&>School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang 330013, Jiangxi, China<&wdkj&>State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, Jiangxi, China<&wdkj&>School of Water Resources and Environmental Engineering, East China University of Technology, Nanchang 330013, Jiangxi, China<&wdkj&>College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
摘要：
Uranium is well-known to have serious adverse effects on the ecological environment and human health. Bioremediation stands out among many remediation methods owing to its being economically feasible and environmentally friendly. This study reported a great promising strategy for eliminating uranium by Stenotrophomonas sp. CICC 23833 in the aquatic environment. The bacterium demonstrated excellent uranium adsorption capacity (qmax = 392.9 mg/g) because of the synergistic effect of surface adsorption and intracellular accumulation. Further analysis revealed that hydroxyl, carboxyl, phosphate groups and proteins of microorganisms were essential in uranium adsorption. Intracellular accumulation was closely related to cellular activity, and the efficiency of uranium processing by the permeabilized bacterial cells was significantly improved. In response to uranium stress, the bacterium was found to release multiple ions in conjunction with uranium adsorption, which facilitates the maintenance of bacterial life activities and the conversion of uranyl to precipitates. These above results indicated that Stenotrophomonas sp. Had great potential application value for the remediation of uranium.
通讯机构：
[Liangxia Duan] C;College of Resources & Environment, Hunan Agricultural University, Changsha 410128, China
关键词：
General linear model;Land use types;Soil aggregates;Soil depth;Soil organic carbon
摘要：
The conversion of natural forests to other land use types generally has a significant influence on soil aggregation and associated soil organic carbon (SOC) concentration, depending on soil depth. However, the dynamics underlying soil aggregate distribution and aggregate-associated SOC concentration after such conversion remain inadequately understood, especially in the red slate soil region of subtropical China, where the stability of soil aggregates is the primary deterrent to soil erosion. This study investigated the effects of land use changes on soil aggregates and aggregate-associated organic carbon content in diverse soil layers in the aforementioned region. Soil samples were collected from seven typical land use types (natural forest, artificial forest, terraced citrus orchard, downhill citrus orchard, kiwifruit orchard, cornfield, and paddy field). Sampling was conducted at a depth of 0 to 100 cm and at 20 cm increments to determine aggregate distribution and aggregate-associated SOC content. Results showed that land use change and soil depth significantly affected aggregate stability and associated SOC concentration. Upon the conversion of natural forests to orchards and croplands, both macroaggregate (>0.25 mm) and SOC concentrations decreased, thereby weakening soil resistance to erosion caused by flowing water. However, the conversion of natural forests to artificial forests did not decrease aggregate stability or aggregate-associated SOC concentration, suggesting that artificial forests are alternative tree species for soil erosion control, aggregate stability enhancement, and SOC fixation. A general linear model indicated that land use changes accounted for 55 % and 56 % of the total variations in SOC concentration in >5 mm and 2.5 mm aggregates, respectively, implying that such changes more significantly affected large-grain aggregates. This study deepens the understanding of SOC accumulation mechanisms and provides valuable information on improving soil quality and physical structure in the red slate soil region of subtropical China.
作者：
Su, Liang;Du, Hu;Zeng, Fuping;Peng, Wanxia;Wang, Hua;...
期刊：
林业研究(英文版),2023年34(5):1323-1331 ISSN：1007-662X
通讯作者：
Hu Du<&wdkj&>Tongqing Song
作者机构：
[Zeng, Fuping; Su, Liang; Song, Tongqing; Wang, Kelin; Du, Hu; Peng, Wanxia; Lu, Menzhen] Chinese Acad Sci, Inst Subtrop Agr, Key Lab Agroecol Proc Subtrop Reg, Changsha, Peoples R China.;[Zeng, Fuping; Su, Liang; Song, Tongqing; Wang, Kelin; Du, Hu; Peng, Wanxia; Lu, Menzhen] Chinese Acad Sci, Guangxi Key Lab Karst Ecol Proc & Serv, Huanjiang Observat & Res Stn Karst Ecosyst, Huanjiang, Peoples R China.;[Su, Liang; Wang, Hua] Hunan Agr Univ, Coll Resources & Environm, Changsha, Peoples R China.
通讯机构：
[Hu Du; Tongqing Song] K;Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academic of Sciences, Changsha, People’s Republic of China<&wdkj&>Guangxi Key Laboratory of Karst Ecological Processes and Services, Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academic of Sciences, Huanjiang, People’s Republic of China<&wdkj&>Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academic of Sciences, Changsha, People’s Republic of China<&wdkj&>Guangxi Key Laboratory of Karst Ecological Processes and Services, Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academic of Sciences, Huanjiang, People’s Republic of China
关键词：
Species composition;Spatial distribution;Variation partitioning;Community assembly;Karst ecosystems
摘要：
Spatial and environmental processes are two ecological processes that have attracted considerable attention in plant community assembly, depending on sampling scale and life history. However, the processes that determine community assembly have not been studied in the karst region of southwest China. In this study, a 25-ha (500 m x 500 m) monitoring plot within the subtropical climax forest in the karst region was established and canonical correspondence analysis was used to reveal the effects of topography and soil on the spatial patterns of tree community assembly. Our study suggests that spatial processes dominate species composition and the combined effects of spatial and environmental processes play an important role. Overall interpretation rate increases with enlarging the sampling scale. However, the pattern of variation partitioning was similar in different life stages. Environmental variables significantly affected species composition at different sampling sizes and life histories and had a higher interpretation rate of species composition on larger sampling sizes. Topographic wetness index was the most important variable to explain species composition of the environmental variables. These results suggest that it is necessary to consider the relative importance of environmental and spatial factors on community assembly to better understand, conserve, and manage subtropical karst forests.
通讯机构：
[Ouyang, NX ; Wei, X ; Ouyang, NX] H;Hunan Univ Finance & Econ, Changsha 410205, Peoples R China.;Hunan Econ Geog Technol Dev Co Ltd, Changsha 410205, Peoples R China.;Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Peoples R China.
关键词：
Available silicon;Parent material;Machine learning;Plough layer;Subsurface layer
摘要：
Silicon can promote rice growth and reduce the toxicity of heavy metals in rice. However, controlling factors for the vertical distribution of silicon in typical paddy soils in mid-subtropical regions of China remain largely unexplored. Here, we aimed to analyze the silicon content in plough and subsurface layers derived from six parent materials in Hunan Province (southern China) based on 62 soil profile samples. Multiple stepwise regression, random forest, and gradient boosting machine learning models were used and compared to predict soil available silicon content and quantify the contribution of different variables on silicon variation. We found that plough layers in the eastern (85% of points) and western (78% of points) Hunan Province were deficient (< 100 mg kg(-1)) in available silicon content. Total silicon content in paddy soil derived from slate (623 & PLUSMN; 100 g kg(-1)) and limestone (606 & PLUSMN; 74 g kg(-1)) was higher than in other soils. The available silicon content was the lowest in granite (51 & PLUSMN; 15 mg kg(-1)). It was closely correlated with available cadmium while being mainly influenced by soil pH, organic carbon, and bulk density. The prediction model of available Si established using a random forest had the highest accuracy (R-2 = 0.74). Widespread deficiency in available silicon content in plough layers of paddy soil in mid-subtropical China highlights the importance and value of higher silicon fertilizer input in soils.
