Table of Content

Volume 40 Issue 3
25 March 2024
Mechanisms of Uptake,Distribution,and Transformation of Farmland Ionic Emerging Organic Pollutants in Crop:A Review
JIANG Yan-qi, HUANG Jian, SHI Ao-ao, XU Kai-ran, REN Jun-ming, NI Zhuo-biao, A Dan, LIN Qing-qi, QIU Rong-liang
2024, 40(3):  293-302.  doi:10.19741/j.issn.1673-4831.2023.0074
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Emerging organic pollutants are taken up by crops, posing a threat to human health via the food chain. The fate of ionic emerging organic pollutants (IEOPs) is more complicated due to their lower volatility and higher polarity. An understanding of the mechanisms of uptake, distribution, and transformation of IEOPs in crops is important for uncovering the fate of IEOPs in farming systems. Here, the crop uptake and translocation processes of IEOPs are reviewed, with a focus on the effects of the physicochemical properties of IEOPs, crop composition, transporters, and controlling genes, etc. The accumulation and distribution patterns of IEOPs in crops are discussed at the organic, tissular, and subcellular levels. Meanwhile, the transformation mechanisms of IEOPs, including the pathways and enzymes involved, are presented. Finally, the directions for future research in this field, e. g., strengthening research on the uptake mechanisms, improving the uptake prediction models, and focusing on in vivo plant transformation, are presented.
Dynamic Change of Carbon Emissions and Environmental Kuznets Curve Empirical Test Analysis in the ASEAN
LAN Yan, HUA Rui-xiang, JING Yi-ran, JIA Xi-chun, LI Jia-wen
2024, 40(3):  303-312.  doi:10.19741/j.issn.1673-4831.2023.0685
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Studying on the dynamic change of carbon emissions in ASEAN member states and analyzing the quantitative relationship between carbon emissions and socioeconomic development can provide a scientific support for China-ASEAN environmental cooperation and other issues. Based on the time series data released by EDGAR and UN Data, the study analyzed the emission structure and trend of ASEAN's carbon emissions. Furthermore, the Mann-Kendall trend test was adopted to explore the carbon peaking situation in ASEAN member states. The Environmental Kuznets Curve (EKC) model was applied to test the relationship between ASEAN member states' per capita carbon emissions and GDP per capita. The results show that: From 1970 to 2021, the total carbon emissions of the ASEAN increased from 1.22×108 t to 1.74×109 t. The top five emitters, including Indonesia, Vietnam and Thailand, accounted for nearly 90% of the total carbon emissions. From 1970 to 2021, the carbon emissions of the power, industrial combustion, others, transportation and building sectors in ASEAN increased by 38.0, 13.6, 12.7, 9.1 and 1.9 times, respectively. The power sector is the primary source of carbon emissions in ASEAN, accounting for more than 40% of total emission. Over the years from 1970 to 2021, the carbon emissions of ASEAN and its member countries have mostly shown an increasing trend every decade. The trend analysis result since 2010 show that Brunei and Thailand may be the earliest ASEAN states to peak carbon emissions. Except Brunei the EKC curves for per capita carbon emissions and GDP per capita are highly parallel for ASEAN member countries. The impact of socioeconomic development on carbon emissions follows the mode of "facilitating-suppressing-facilitating", with different inflection points in different countries. Therefore, it is recommended that China to strengthen cooperation in clean energy and power sector with ASEAN member states, as well as maintain continuous investment and policy continuity in environment protection.
Spatial-temporal Characteristics of Trade-off and Synergy of Ecosystem Services in the Loess Plateau under Constraint of Different Grazing Intensity
LI Ting, QIAO Zhi-hong, FENG Wei-han, YANG Ya-dong
2024, 40(3):  313-324.  doi:10.19741/j.issn.1673-4831.2023.0317
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Clarifying the effects of grazing interference on ecosystem services is an important basis for the sustainable grazing managements. The northern farming-pastoral zone traverses the Loess Plateau, for which ecological restoration on this region still survives the impacts of grazing disturbance. In this paper, the grazing intensity across the Loess Plateau was estimated by using the global livestock density data and remote sensing vegetation index. Then, the constraint effects of grazing intensity on three ecosystem services namely water yield, forage provision and soil conservation in 2000 2010 and 2020 were examined by using the constraint line extraction method. On this basis, the spatial-temporal characteristics of trade-off and synergy of ecosystem services from 2000 to 2020 in the Loess Plateau under different grazing intensity were explored. The results show that: (1) the study area was dominated by the low-level grazing intensity and moderate-level grazing intensity by 2020. The area proportion of high-level grazing intensity only accounted for 5.30%. (2) Grazing intensity showed negative constraint effects on all three ecosystem services, which however, a higher grazing intensity indicated a larger amount of water yield within a certain threshold range. (3) From 2000 to 2020, the synergies among ecosystem services in the high-level grazing area were severely weakened. Under the moderate-level grazing intensity, the synergies among ecosystem services increased on different levels, and trade-off between water yield and forage provision in 2000 had been turned into synergic relationship in 2020. However, on the low-level grazing areas, synergic relationship between water yield and forage provision with correlation coefficient of 0.29 in 2000 had been turned into trade-offs in 2020, with correlation coefficient of -0.14. These results reveal that within the 20 years, the improvement of ecosystem function benefited from policy of grazing prohibition has show an effect of diminishing marginal. The consideration on types of grazing livestock combined with the spatial heterogeneity of ecosystems is a prerequisite for developing moderate grazing in arid regions for the improvement of ecosystem functioning in drylands.
The Space-time Relationship between the Ecosystem Service Value and the Human Activity Intensity in Xi'an Metropolitan Area
ZHU Lin-na, ZHAO Mu-dan, LI Yun-fei, FAN Yi, WANG Jian
2024, 40(3):  325-334.  doi:10.19741/j.issn.1673-4831.2022.1078
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Human activity is one of the most important factors that affects the changes of ecosystem service value (ESV), so the exploration of their spatio-temporal relationship would facilitate a coordinated development between ecology, environment, society and economy. By taking Xi'an metropolitan area as the research object, this study constructed four models including an ESV assessment model, an ESV flow gain/loss model, a human activity intensity (HAI) index assessment model, and a bivariate spatial autocorrelation model, based on the land use data in 1990, 2000, 2010, and 2018 at a grid scale of 2 km×2 km, so as to get insights into the spatiotemporal relationship between ESV and the intensity of human activities. The results of this study demonstrate that: (1) Between 1990 and 2018, the ESV in Xi'an metropolitan area showcased a continuous downward trend on the time scale, with a total decrease of RMB 1.28 billion yuan over the past 30 years; on the spatial scale, it showed an increasingly widened distribution pattern centered on Xi'an's main urban area, with an extension to the periphery; (2) The ESV gain mainly stemmed from the conversion of cropland to forest land, water and grassland, while the ESV loss mainly caused by the transfer-in of cropland and construction land as well as the transfer-out of waters; (3) The intensity of human activities showed a decreasing spatial distribution pattern from the center of Xi'an City to both of its northern and southern regions, with the high-impact zones concentrated in Xi'an's main city and its periphery, while the low-impact ones were distributed at the northern and southern ends of the research area; and (4) ESV is negatively correlated with the intensity of human activities, with the clustering relationships between the two dominated by low-high and high-low aggregation modes. The low-high and high-low aggregation areas have a high significance level. It is expected that this study on the spatiotemporal relationships between ESV and the intensity of human activities would provide theoretical support for the sustainable development of related regions.
Research on the Spatial and Temporal Evolution of Landscape Pattern in Sanming Urban Area and the Construction of Ecological Network
ZENG Zhen, AI Jing-wen, WANG Zi-ling, HE Tian-you, ZHENG Yu-shan
2024, 40(3):  335-344.  doi:10.19741/j.issn.1673-4831.2022.1013
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The construction of the ecological network can help to make full use of the superior eco-environment of mountainous cities, restore the negative impact of rapid urbanization, and enhance regional ecosystem services and biodiversity. Taking the urban area of Sanming City as the research area, the changes of landscape pattern, ecological sources and ecological resistance surface in 2000, 2010 and 2020 were compared and analyzed. And the morphological spatial pattern analysis (MSPA), circuit theory, and gravity model were used to identify important ecological sources, build ecological corridors, and propose corresponding optimization strategies. The results show that: (1) From 2000 to 2020, the proportion of the core area all accounted for more than 50% of the total area of Sanming urban area, but showed a downward trend year by year. (2) 11 important ecological sources were identified, and 24 ecological corridors have been constructed. (3) Three types of eco-corridors was divided by the gravity model, including 2 first-level corridors, 5 second-level corridors, and 17 third-level corridors. (4) 22 stepping stones, 47 ecological pinch points, 54 obstacle points and 114 breaking points were identified. (5) The optimization strategies of restoring ecological breaking points, building stepping stones, protecting ecological pinch points, and removing ecological barrier points are proposed for the improvement of the stability of the ecological network and for enhancing the connectivity of regional landscapes. The results of this study can provide references for the construction of ecological network in mountainous cities.
Study on the Spatio-temporal Correlation between Multidimensional Urbanization and the Evolution of Rural Territorial Functions: A Case Study of Jianghan Plain
LIN Pan, YU Bin, WU Jie-meng
2024, 40(3):  345-362.  doi:10.19741/j.issn.1673-4831.2023.0489
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Exploring the complex correlation between urbanization and the evolution of rural territorial functions is not only an important proposition of rural-urban integration and rural revitalization in the new era, but also the frontier of rural geography research. Taking Jianghan Plain in 2000-2019 as the research case, based on the urbanization index system and rural territorial function evaluation model, this paper explores the temporal correlation regularity and spatial correlation characteristics between multidimensional urbanization and rural territorial functions by applying the method of systematic dynamic panel model, spatio-temporal geographic weighted regression model. The results show that: (1) there are obvious structural differences in the evolution of rural territorial functions in Jianghan Plain, in which the comprehensive function of rural areas had changed in stages in terms of time, and it had evolved from an inverted U-shaped distribution pattern along the development axis of Jiaoliu-Changjing to a T-shaped distribution pattern along the Hanyi Line-East Plain Belt in terms of space. (2) Multidimensional urbanization and rural territorial functions in Jianghan Plain showed complex characteristics in temporal correlation. On the one hand, the correlation between population, economic urbanization and comprehensive function of rural areas show an "N"-shaped curve regularity, and the correlation between urbanization and comprehensive function of rural areas presented a monotonic increasing trend. On the other hand, the elastic coefficient value was lower than the positive effect value of population and economic urbanization in the later period. (3) The spatial correlation between multidimensional urbanization and rural territorial functions in Jianghan Plain shows obvious regularity and heterogeneity. The research results are helpful to enrich the theoretical connotation of rural geography and provide support for the practice of rural-urban integration and rural revitalization in Jianghan Plain.
Interannual Effects of Climate Factors on Community Characteristics of Different Vegetation Types in Ulanqab Steppe
HAN Xue-jiao, TU Ya, LIU Xiao-juan, ZHU Yuan-jun, SHI Zhong-jie, YANG Xiao-hui
2024, 40(3):  363-373.  doi:10.19741/j.issn.1673-4831.2023.0457
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With the gradual intensification of global climate change, the impact of climate factors such as temperature, precipitation, and wind speed on steppe communities is increasing. Exploring the effects of climate change on community characteristics of different vegetation types is of vital significance for studying steppe ecological processes, rational utilization and conservation of steppe resources, and the ecological restoration of degraded steppes. In this study, three climate factors, namely, annual average temperature, annual precipitation, and annual average wind speed, were investigated by using a plot survey method to analyze the interannual effects of different community characteristics of rhizome steppe, tussock steppe, shrubby/semi-shrubby steppe and forb steppe in Ulanqab grassland from 2010 to 2020. The following conclusions were drawn: (1) The annual average temperature, annual precipitation, and annual average wind speed exhibited a fluctuating increasing trend for the tussock and forb steppe; the annual mean temperature and annual mean precipitation of rhizome steppe and shrubby/semi-shrubby steppe showed a trend of increasing year by year, and the annual mean wind speed showed a trend of decreasing year by year. (2) The interannual changes of the 4 community characteristics of tussock steppe, rhizome steppe and forb steppe showed an overall trend of increasing year by year, while the interannual changes of the 4 community characteristics of shrubby/semi-shrubby steppe were not obvious. (3) Annual average temperature exerted the greatest influence on the characteristics of rhizome steppe and forb steppe communities, while it had no significant impact on the characteristics of shrubby/semi-shrubby steppe communities. Annual average wind speed had the most significant effect on the characteristics of the forb steppe community. Annual precipitation demonstrated a significant positive correlation with the characteristics of all four vegetation types, and its influence on the community characteristics of the Ulanqab Steppe region surpassed that of the annual average temperature and annual average wind speed, making it the primary climate factor impacting the community characteristics in this region.
Identification and Fingerprint Construction of Hippophae rhamnoides Varieties Based on EST-SSR Markers
ZHAO Yu-xin, ZHANG Zhe-wen, KAO Hui-xia, SUN Yong-jiang, XIN Zhi-ming, ZHAO Zhe, DONG Shu-bin, CHENG Jin
2024, 40(3):  374-385.  doi:10.19741/j.issn.1673-4831.2023.0018
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To achieve swift and precise variety identification of Hippophae rhamnoides, a set of EST-SSR (express sequence tags from simple sequence repeat) markers was developed. These markers exhibit high polymorphism, stability and generality, and have allowed the construction of the fingerprint of H. rhamnoides. For the transcriptome sequencing data, the young and fresh leaves of 'Shiyou 1’ were selected for RNA extraction and cDNA library construction. Additionally, young and healthy leaves from 42 varieties of H. rhamnoides were collected. The EST-SSR markers were designed by using microsatellite identification tool (MISA) and Primer 3 (version 2.3.4). PCR and TP-M13-SSR combined capillary electrophoresis examined fluorescence signals and peak emergence for 42 varieties. Amplified product lengths and genetic information of EST-SSR markers were assessed by using GeneMarker (version 2.2.0), Popgene (version 1.32), Cervus (version 3.0.7), and Convert (version 1.31). Genetic relationship analysis of the varieties was conducted by using NTSYSpc (version 2.10e). As a result, a total of 6 196 SSR loci were obtained, with 182 motifs types among all the SSR loci. The dominant motif was (A/T) n. The lengths of the SSR motifs were 10-21 bp, accounting for 81.58% of all SSR sequences. The main types of SSR repeat motifs were mono-nucleotide (48.72%), di-nucleotide (22.68%) and tri-nucleotide (18.85%). 28 pairs of primers were developed and a total of 193 allele loci in the 42 varieties were detected. The genetic diversity indexes, including the mean number of observed alleles (Na), effective number of alleles (Ne), observed heterozygosity (Ho), expected heterozygosity (He), polymorphism information content (PIC) and Shannon information index (I) were 6.964, 3.495, 0.617, 0.671, 0.623 and 1.384, respectively. The genetic similarity coefficients between varieties ranged from 0.601 to 0.990, as determined by UPGMA clustering. At a coefficient of 0.694, varieties formed two groups, while at coefficient to be approximately 0.740 2, they grouped into three. Using six selected primers, the fingerprint of H. rhamnoides was constructed for rapid and accurate variety identification. This study provides the theoretical basis and molecular-level data support for variety identification, fingerprint construction, genetic diversity and relationship analysis of H. rhamnoides.
Spatiotemporal Distribution and Influencing Factors of Bird Diversity Hotspots in Suzhou Wetland
JIANG Lin-lin, ZHANG Yi, YANG Yu-jia, ZHU Yuan-hang, MU Qing, YANG Zhao-hui
2024, 40(3):  386-397.  doi:10.19741/j.issn.1673-4831.2022.1004
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Wetland birds play an important indicative role in wetland ecosystems, and their diversity monitoring is beneficial for wetland conservation. Taking Suzhou City as the research area, a maximum entropy model was employed to simulate and analyze the spatial distribution patterns and spatiotemporal variation of 41 water bird diversity hotspots in 2018, 2019, and 2020. Environmental variables, including annual average precipitation, point of interest (POI) kernel density, land use type, and proximity to water source, wield substantial influence over the birds' spatial distribution. Over the triennium, primary influencing factors exhibited noteworthy fluctuations, while anthropogenic disturbances demonstrated a more consistent profile. Notably, the spatial extent of waterbird diversity hotspots demonstrated a progressive expansion, primarily concentrated along the northern coastal wetlands of the Yangtze River and the expansive lake wetlands surrounding Taihu Lake in the southwest. This trend is anticipated to intensify further. Comparative analysis of hotspot distribution between migratory and resident waterbirds, notably dominated by species such as Alcedo atthis, Egretta garzetta, Amaurornis phoenicurus, and Podiceps ruficollis, reveals larger hotspots for the latter group. Given the burgeoning hotspot areas, monitoring points established in 2019 are deemed insufficient for comprehensive waterbird surveillance in Suzhou. Consequently, it is recommended to add 15 monitoring areas, including Shuangshan Island area, Tongsha Wharf area, and Wangyu River.
Effects of Soil Parent Material and Farmland Utilization on Nitrogen Distribution in Soil Profile in Chengdu Plain
RAN Min, SONG Liang-ying, XUE Jing-ling, ZHANG Yuan-yuan, ZHANG Hao, WU De-yong, LI Qi-quan
2024, 40(3):  398-407.  doi:10.19741/j.issn.1673-4831.2023.0047
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Understanding the profile distribution characteristics of soil nitrogen and its influencing factors in the farmland is essential for regional nitrogen fertilizer management and control of non-point source nitrogen pollution. Based on 1 356 samples from 173 soil profiles on the Chengdu Plain, this study analyzed the spatial variation characteristics of soil nitrogen in farmland soil profile using geostatistics and variance analysis and identified the effects of agricultural land use types and soil parent materials on the nitrogen distribution in soil profile. The results show that the contents of total nitrogen (TN) and available nitrogen (AN) decreased significantly from 1.91 g·kg-1 and 138.48 mg·kg-1 to 0.55 g·kg-1 and 25.39 mg·kg-1, respectively, in the 0-100 cm soil layer with the increase in soil depth. Spatially, the contents of TN and AN in each soil layer had a similar spatial distribution pattern, which showed an increasing trend from the central to the northeast and southwest. There was no significant difference in the contents of TN and AN of each soil layer between rice-vegetable rotation land and rice-wheat/rapeseed rotation land, while the contents of TN and AN in the surface layer (0-20 cm) of afforested land were 11.23%-15.78% lower than those of the other two land uses (P<0.05). Compared with soils formed from Q4 gray alluvium, soils formed from Q3 old alluvium had 1.12-1.19 times of TN and AN content in 0-40 cm soil layer (P<0.05) and 0.89 times of TN content in >60-100 cm soil layer (P<0.05), while the contents of TN and AN in the 0-40 cm soil layer of soils formed from Q4 gray-brown alluvium were 1.14-1.21 times as those in the Q4 gray alluvium (P<0.05). There were no significant differences in the contents of TN and AN under different land uses in each layer of Q3 old alluvium developed soil (P>0.05). For afforested land, soils formed from Q4 grey alluvium and Q4 grey-brown alluvium in afforested land had lower TN and AN content in the topsoil than the other two land use types, but had higher TN and AN content below the >20-40 cm soil layer. The above results suggest that the profile distribution characteristics of soil nitrogen are affected by agricultural land use types and such effects are controlled by soil parent material.
Spatial and Temporal Dynamics of Soil Quality in Representative Farmland of Fengqiu County
XIE Yue, MA Dong-hao, WANG Qing-yun, ZHAO Bing-zi, ZHU An-ning, ZHANG Cong-zhi, ZHANG Jia-bao, Li Xiao-peng
2024, 40(3):  408-417.  doi:10.19741/j.issn.1673-4831.2022.1170
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The Huang-Huai-Hai Plain is an important agricultural region in China, taking an overall system evaluation of its typical soil quality changes holds great significance in guiding agricultural production. Fengqiu County was chosen as the study area, and the data of the typical tidal soil of the county of the years of 1984, 2003, and 2011 consisting of 17 soil indexes were used. These indexes were based on soil functions within ecological processes such as crop production, carbon sequestration, water purification, nutrient transport, and others, to construct an integrated soil quality evaluation system. Functional scores and the comprehensive index of soil quality were computed using principal component analysis combined with the TOPSIS ranking method. The spatial and temporal changes of the 27 years in soil quality and function within the tidal soil tillage area of Fengqiu County were depicted through GIS spatial interpolation. The results reveal: (1) The levels of soil total nitrogen, total phosphorus, alkaline nitrogen, available phosphorus, available potassium, organic matter, cation exchange capacity, saturated hydraulic conductivity, and porosity in Fengqiu County displayed varying degrees of increasing trends, while total potassium content, pH levels, bulk density, field water capacity, and available water content decreased annually. (2) Soil functions related to crop production, carbon sequestration, and nutrient transport in Fengqiu County increased by 9.29%, 9.68%, and 7.36%, respectively, while the score for water retention and purification function decreased by 4.17%. (3) The comprehensive index of soil quality improvement in Fengqiu County became more apparent. In 1984, all the comprehensive index of soil quality in farmland across the county was ≤2.0, while by 2003, the area with the index >2.0 accounted for 8.44% of the total county area, and the percentage of the area with the index >2.0 was further raised to 24.05% in 2011. Overall, the protection and utilization strategies for cultivated land in Fengqiu County over the 27 years were proven to be largely effective, leading to a continuous development towards improved overall quality. These findings can serve as a reference for sustainable use of cultivated land resources in the Huang-Huai-Hai Region.
Properties and Mechanisms of Humic Acid Adsorption by Hematite at Different Temperatures
ZHOU Can-yao, DAI Wei, LUAN Ya-ning, WANG Xu-qin
2024, 40(3):  418-425.  doi:10.19741/j.issn.1673-4831.2023.0696
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The effects of temperature on the adsorption of organic matter by soil minerals were investigated by studying the adsorption of humic acid on hematite at different temperatures. Adsorption kinetic tests were performed and the mechanisms of humic acid adsorption on hematite at different temperatures were clarified by using a combination of scanning electron microscopy, energy-dispersive spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction, and zeta-potential measurements. The experimental results show that the equilibrium amounts of humic acid adsorbed on hematite at 25, 30, 35, and 40 ℃ were 28.52, 28.99, 29.74, and 30.69 mg·g-1, respectively indicating that the higher the temperatures, the higher the adsorption of humic acid on hematite. The adsorption kinetics of humic acid on hematite at different temperatures were better described by a quasi-secondary kinetic model than by a quasi-primary kinetic model. This indicates that the adsorption rate is mainly determined by a chemisorption mechanism. With increasing temperature, the C/Fe ratio on the hematite surface gradually increased, the single-particle size gradually increased, the crystallinity decreased continuously, and the zeta potential initially increased and then decreased. The FTIR spectra showed that the trends in the amounts of various functional groups present differed. In conclusion, increasing the temperature promotes the adsorption of organic matter by soil minerals.
Study on Phosphorus Release Characteristics and Influencing Factors in Sediments of Different Ecological Types
LIU Fei-fei, WANG Wei-ping, WANG Wan-zhong, CHAO Jian-ying, HAN Tian-lun
2024, 40(3):  426-436.  doi:10.19741/j.issn.1673-4831.2023.0400
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To investigate the phosphorus (P) release characteristics and influencing factors of sediments from three different ecological types, black-odor river (BO-S), algal lakes (A-S) and macrophytic lakes (M-S), physical and chemical characterization, as well as release kinetics model were employed. In addition, the effects and mechanisms of anions (CO32-, SO42-, NO3-, HCO3- and Cl-) and dissolved organic matter (fulvic acid and humic acid) on the P release characteristics of the three types of sediments were explored. The results show that the three types of sediments exhibited distinct different P release patterns. BO-S and A-S sediments primarily released soluble reactive P (SRP), accounting for 56.00% and 57.14% of the total release contents, respectively, while M-S sediments predominantly released dissolved organic P (DOP), which accounted for as much as 81.40% of the total release contents. Both anions and dissolved organic matter facilitated the release of P from sediments. Anions, particularly CO32-, were the most effective in promoting the release of SRP. Compared to the control group, a concentration of 10 mmol·L-1 of CO32- led to an average increase of 39.2 times in the maximum release of SRP. Dissolved organic matter, particularly humic acid, mainly promoted the release of DOP. At a concentration of 100 mg·L-1, humic acid caused an average increase of 56.3 times in the maximum release of DOP from sediments compared with the control group. Furthermore, the changes in the content of metal-bound P in sediments before and after P release indicated that anions and dissolved organic matter primarily promoted P release by competing for P adsorption sites on metal oxides.
Effects of Different Passivation Materials on the Accumulation and Transport of Cd and Pb in Maize
LIU Qi, WANG Sheng, CHEN Wen, ZHAO Xuan-yue, BAO Li, ZHANG Nai-ming
2024, 40(3):  437-448.  doi:10.19741/j.issn.1673-4831.2023.0075
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The "Huaxing dan 88" maize variety was used to explore the effect of different passivation material combinations and dosages on Cd and Pb absorption by maize and facilitate safe crop production in heavy metal-contaminated farmland. This study also used field experiments to examine the impact of "Jiangge ling" foliar inhibitor (JGL), organic fertilizer (YJF), humic acid (FZS), and soil heavy metal passivator (DHJ) spraying and the different dosage combinations on the biological traits of maize, the Cd and Pb levels, the bioconcentration factor (BCF), and translocation factor (TF). The BCF of the Cd and Pb in the maize grains was used to calculate the soil Cd and Pb risk threshold (T) as a resistance evaluation index. The results show that the nine resistance control measures increased the yield by 14.4% to 32.3% compared with CK, with the yield increasing ability exhibiting an order of JGL++++. The Cd and Pb levels and Cd BCF and Pb BCF values in the maize grains decreased from 31.0% to 65.5%, 18.2% to 59.1%, 33.2% to 68.7%, and 16.8% to 57.6%, respectively, compared with CK. The control effect of Cd and Pb was JGL>DHJ>YJF1>DHJ+>YJF1+>YJF2>FZS>YJF2+>FZS+. The Cd and Pb content and enrichment were highest in the roots of the maize and lowest in the grains. The stem-leaf transport ability of Cd and Pb was the strongest, while the root-stem capacity was the weakest. Field experiments confirmed that the yield and Cd and Pb control effect of the maize exposed to the 10 treatments were FZS+>YJF2+>FZS>YJF2>YJF1+>DHJ+>YJF1>DHJ>JGL>CK. The soil TCd and TPb of the tested maize were between 11.0-23.1 mg·kg-1 and 109.9-218.0 mg·kg-1, respectively. Therefore, FZS is recommended as a passivation material in the maize production area under mild to moderate Cd pollution since it has displayed the best yield increase and Cd and Pb resistance effect, and FZS+ is recommended as a combination measure which has exhibited the best yield increase and Cd and Pb resistance effect in the maize production area under severe Cd pollution.