环境科学最新文献

{"title":"[Characteristics and Influencing Factors of Soil and Crops Selenium Content in Eastern Sanjiang Plain].","authors":"Jing-Jie Li, Tao Yang, Ming-Guo Wang, Sheng Lian, Yong-Gao Lü, Jing-Yi Cai","doi":"10.13227/j.hjkx.202310047","DOIUrl":"https://doi.org/10.13227/j.hjkx.202310047","url":null,"abstract":"<p><p>Too identify seleniut（Se） content characteristics and influencing factors in soil and crops of Shengli Farm in eastern Sanjiang Plain, statistical analysis and correlation analysis were comprehensively used to analyze the test results of 83 groups of surface soil samples and 34 groups of crop seed samples. The results showed that the Se content in the study area ranged from 0.12 to 0.95 mg·kg^-1, with an average value of 0.37 mg·kg^-1, and the enrichment degree was stronger with an enrichment coefficient of 3.18. Oxidizable Se was the main Se fraction, accounting for 81%, 79%, 79%, and 80% of T-Se in marsh soil, white soil, dry land, and paddy field, respectively. The content of reducible Se was the lowest, accounting for less than 5%. The effects of soil physicochemical indexes on Se content differences mainly showed that Se was negatively correlated with pH and total potassium （TK） and significantly positively correlated with cation exchange capacity （CEC）, soil organic matter （SOM）, humus （HS）, total nitrogen （TN）, and total phosphorus （TP）. The average content of Se in different land use types was as follows： dryland &gt; irrigated land &gt; grassland &gt; forest land, as the dryland soil with low pH and high SOM was more likely to enrich Se. Among different soil types, the average Se content in gleysols was the highest at 0.45 mg·kg^-1, which was higher than the average value in the study area. The average content of Se in the quaternary alluvial layer was the highest at 0.43 mg·kg^-1, and its parent material mainly consisted of lacustrine sediments rich in organic matter, which was one of the important factors in forming Se rich soil. The Se content in crops and root soil showed a negative correlation. Se in low pH or high SOM soil was not easily absorbed by crops, and its Se content was also controlled by the form of soil Se, which was positively correlated with available Se content and negatively correlated with oxidizable Se content. Therefore, it is suggested to reduce the amount of artificial fertilizer used in cultivated land as a means of increasing Se bioavailability to change the current situation of crop Se levels in this area.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"6195-6206"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effects of Climate Changes and Crop Phenological Responses on Soil Organic Carbon of Cultivated Land in Fujian Province].","authors":"Yi-Fan Li, Ting Wu, Yuan Yao, Zhi-Qiang Li, Jin-Quan Shen, Huai-Kai Weng, Li-Ming Zhang, Shi-He Xing","doi":"10.13227/j.hjkx.202309159","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309159","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Research on the mechanism of how climate change affects cultivated soil organic carbon is the basis for the management of cultivated land quality in the context of climate change. Crop phenological responses to climate change have an important effect on cultivated soil organic carbon as well. However, previous research primarily focused on the independent effects of climate change or crop phenological responses on the changes in soil organic carbon, and few studies have analyzed the changes in cultivated soil organic carbon under the combined influence of both factors or quantified their contribution rates to the changes in cultivated soil organic carbon. Based on topsoil samples in 2008 and 2021, annual pre-season and mid-season climate data from 2008 to 2021, and the phenological parameters extracted from the enhanced vegetation index （EVI） time series from 2007 to 2022, a soil organic carbon predictive model was constructed using the random forest algorithm. The total change in soil organic carbon from 2008 to 2021, the change in soil organic carbon under climate change alone, and the change in soil organic carbon under the synergistic influence of climate change and crop phenological responses were simulated. Furthermore, the contributions of climate change and crop phenological responses to the changes in cultivated soil organic carbon were distinguished and quantified. Moreover, the dominant influencing factors of soil organic carbon changes and their spatial distributions were identified and analyzed. The results were as follows： ① Under the synergistic influence of climate change and crop phenological responses, a decrease was observed in soil organic carbon in 74.15% of the cultivated land area in Fujian Province during the years 2008-2021, with an average decrease of 2.20 g·kg&lt;sup&gt;-1&lt;/sup&gt;. Additionally, there was an increase in soil organic carbon in 25.85% of the cultivated area, with an average increase of 1.48 g·kg&lt;sup&gt;-1&lt;/sup&gt;. ②The average contribution rates of pre-season climate, crop phenological responses to climate change, mid-season climate, and phenological changes resulting from cultivars shifts or other adjustments of agricultural measures to soil organic carbon changes were 34.08%, 28.56%, 22.75%, and 14.61%, respectively. Overall, climate change had a greater impact on the changes in cultivated soil organic carbon in Fujian Province than the crop phenological response to climate change. ③ The regions where climate change and phenological response jointly acted as dominant influencing factors held the largest area, accounting for 47.06% of the total cultivated land area in Fujian Province, and the regions where climate change was the dominant influencing factor alone held the second-largest area, accounting for 28.64% of the total cultivated land area. ④ Higher contribution rates of pre-season climate factors and phenological changes resulting from cultivar shifts or other adjustments of agricultural measures tended","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"6012-6027"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Land Cover Simulation and Carbon Storage Assessment in Daqing City based on FLUS-InVEST Model].","authors":"Xue Li, Wen Li, Yu Gao","doi":"10.13227/j.hjkx.202312007","DOIUrl":"https://doi.org/10.13227/j.hjkx.202312007","url":null,"abstract":"<p><p>Considering Daqing City as the research area, the impact of land cover change on carbon storage in the future was discussed, and the hot spots of carbon sequestration capacity were identified. The future land use simulation （FLUS） model was used to simulate the land cover pattern of a natural succession scenario, ecological protection scenario, urban development scenario, and comprehensive development scenario in 2030, and the integrated valuation of ecosystem services and trade-offs （InVEST） model was combined to estimate carbon storage in 2010, 2020, and 2030. Finally, the hot spot analysis tool was used to identify the cold hot spots of carbon sequestration capacity. The results showed the following： ① From 2010 to 2020, the area of cultivated land, water, and artificial surface increased, whereas the area of other land cover types decreased, and the total carbon storage decreased by 8.6×10⁵ t. ② The land cover change of the natural succession scenario and urban development scenario in 2030 was similar to that of 2010-2020, with carbon storage decreasing by 1.16×10⁶ t and 1.20×10⁶ t, respectively. The carbon storage of the comprehensive development scenario decreased by 1.00×10⁶ t compared with that in 2020, and carbon storage of the ecological protection scenario was 5.677 7×10⁸ t, which increased by 2.53×10⁶ t compared with that in 2020. ③ The conversion of grassland and wetland to cultivated land was the main cause of carbon storage loss, and the main contributor of carbon storage in the ecological protection scenarios was wetland. ④ The hot spots of carbon sequestration capacity were mainly located in the wetland area, and the cold spots were mainly distributed in the central part of Daqing City. The carbon sequestration capacity of cultivated land was not significant. According to the research results, to realize the urban transformation of Daqing City, we should insist on returning farmland to forest and grass, increase the intensity of returning moisture, improve the utilization rate of urban land, and increase green infrastructure in the main urban area.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"5983-5993"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Spatio-temporal Situation, Regional Differences, and Dynamic Evolution of the Distribution of Ecological Compensation in the Yellow River Basin].","authors":"Zheng-Nan Zhao, Shao-Feng Ru","doi":"10.13227/j.hjkx.202312039","DOIUrl":"https://doi.org/10.13227/j.hjkx.202312039","url":null,"abstract":"&lt;p&gt;&lt;p&gt;In the context of regional coordinated development and modernization of ecological and environmental governance capacity, the spatial collaborative governance of transboundary river basins has received extensive attention, but the ecological compensation of river basins is faced with the intertwined relationship of rights and responsibilities, and the horizontal ecological compensation mechanism has not yet been perfected. Based on the emergy ecological footprint model, the ecological compensation amount of 90 cities in the Yellow River Basin in 2007-2021 was measured, and the spatiotemporal pattern, regional differences, and dynamic evolution characteristics of distribution were explored by combining exploratory spatial data analysis, Dagum Gini coefficient, kernel density estimation, and spatial Markov chain analysis. The results showed that： ① The spatiotemporal pattern of ecological compensation in the Yellow River Basin was different, the ecological compensation amount decreased slightly in the fluctuation and increased from the northwest to southeast gradient in general, and the high-value areas were concentrated in the areas with a superior ecological background or developed economy, and some upstream cities had given up many development opportunities to maintain the ecological security of the Yellow River Basin, however, failed to obtain reasonable ecological compensation. ② A significant positive spatial agglomeration phenomenon was observed in ecological compensation and the overall spatial distribution trend was \"cold in the north and hot in the south.\" The number of low-payment areas and low-compensation areas gradually decreased, showing a gradually shrinking agglomeration layout from the periphery to the center, whereas the number of high-payment areas and high-compensation areas continued to increase and formed a spatial evolution characteristic of the coexistence of scattered distribution and group distribution. ③ The overall regional differences in ecological compensation expanded. The over-variation density was the main source of the overall differences, and the focus on alleviating the intra-regional and inter-regional differences was located in the downstream areas. ④ A slight multi-level differentiation phenomenon was present in ecological compensation. The influence of different neighbors on the horizontal transfer of ecological compensation was quite different. This spatial spillover effect easily formed a \"space club convergence\" phenomenon within a certain geographical spatial range, but with the expansion of time, the probability of maintaining the original level of ecological compensation in each city decreased, and mobility gradually increased. Therefore, increasing the investment in ecological compensation in different fields, strengthening the coordinated development between regions, and giving full play to the spatial spillover effect are important ways to solve the current spatial imbalance of ecological comp","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"5853-5867"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Temporal and Spatial Variations of Soil Organic Carbon and the Influencing Factors in Shaanxi Province in Recent 30 Years].","authors":"Xiao-Lin Feng, Yu-Yang Yan, Xin-Ran Zhang, Chu-Tian Zhang, Zeng-Chao Geng, Fei-Nan Hu, Chen-Yang Xu","doi":"10.13227/j.hjkx.202311169","DOIUrl":"https://doi.org/10.13227/j.hjkx.202311169","url":null,"abstract":"<p><p>Soil organic carbon （SOC） variation is a significant indicator for the soil quality dynamic and global carbon cycle. Therefore, it is necessary to study the regional temporal and spatial distribution of SOC pool and the influencing factors. In this study, a total of 540 soil data and environmental variables were collected from Shaanxi Province during a 30-year period from 1985 to 2015, and univariate analysis of variance and path analysis were used to explore the temporal and spatial distribution characteristics of SOC content and the influencing factors of SOC change. The results showed that the SOC contents of Shaanxi Province in both 1985 and 2015 were the highest in central Shaanxi, followed by those in southern Shaanxi, and they were significantly higher than those in northern Shaanxi. From 1985 to 2015, the increase in SOC in southern Shaanxi was the highest （21.28%）, and that in central Shaanxi was 15.33%. The content of SOC in northern Shaanxi was decreased by 10.23%, caused by significant decrements in the bottom horizons of 60-80 cm and 80-100 cm. Compared with that in 1985, the increases in SOC content in the 0-100 cm soil profile （with every 20 cm as a horizon） ranged from 3.21% to 29.39% in 2015. The increase in SOC content of skeletal soils was largest, followed by that of alluvial soils. Correlation analysis and path analysis showed that SOC content was positively correlated with altitude, average annual precipitation, normalized vegetation index, and total nitrogen content and was in significant negative correlation with curvature, bulk density, and pH. Total nitrogen content was the main controlling factor affecting SOC content. The results of the study can provide reference for future carbon management measures in the region.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"5994-6001"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Daily NO₂ Simulation Research Based on Automatic Machine Learning Ensemble Models].","authors":"Kai-Kai Lu, Jing Li, De-Ren Liu, Fa-Zhao Xu, Yu-Na Zhang, Shi-Xing Zhu","doi":"10.13227/j.hjkx.202311087","DOIUrl":"https://doi.org/10.13227/j.hjkx.202311087","url":null,"abstract":"<p><p>To understand the spatial distribution of NO₂ near the surface, we utilized measured data from NO₂ monitoring stations and combined it with column concentration data from the Tropospheric Monitoring Instrument （TROPOMI）, taking the Yangtze River Delta region as the study area. We considered the impact of factors such as population, elevation, and meteorological conditions on NO₂ levels. We used automated machine learning to select five machine-learning algorithms with high simulation accuracy, namely ET, RF, XGBoost, LightGBM, and Catboost, and then integrated these five algorithms using the Stacking model to simulate the daily NO₂ concentration in the Yangtze River Delta region from March 2020 to February 2021. The results indicated that the RMAE and MAE values of the Stacking ensemble model were 7.078 and 5.270, respectively, which outperformed the single algorithms of ET, RF, XGBoost, LightGBM, and Catboost. The spatial distribution of high NO₂ concentrations in the Yangtze River Delta region, consisting of three provinces and one municipality, exhibited a U-shaped pattern with the convergence point located at the intersection of the three provinces, extending towards the southwest. Notably, urban pollution was particularly significant in the urban agglomerations centered around Shanghai, Hangzhou, Nanjing, and Hefei. There were 27 cities that exceeded the national standard daily limit. Changzhou was the city with the most serious NO₂ pollution, with the NO₂ concentration exceeding the standard for 14 d, followed by Shanghai, with 13 d. In terms of seasonal variation, the order of severity was as follows： winter, autumn, spring, and summer, with the least NO₂ pollution occurring on July 9th during the summer, and the most severe NO₂ pollution was observed on December 23rd during the winter.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"5740-5747"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Simulating Changes in Ecosystem Carbon Storage and Analyzing Influencing Factors in the Central Zhejiang under the Background of LUCC].","authors":"Jia-Jia Zhou, Yu Liu, Li-Jun Feng, Xiao-Lan Wen, Hao Guo","doi":"10.13227/j.hjkx.202309192","DOIUrl":"https://doi.org/10.13227/j.hjkx.202309192","url":null,"abstract":"<p><p>Central Zhejiang is the key ecological function area of Zhejiang Province and an important part of the Qiantang River ecological corridor. Conducting simulations of ecosystem carbon storage changes and analyzing influencing factors under land-use changes in this region is of significant importance for achieving the goals of \"peak carbon\" and \"carbon neutrality\" at an early stage. This study, based on the land use data of five periods from 1980 to 2020 in central Zhejiang, coupled the GeoSOS-FLUS and the InVEST model to analyze the spatiotemporal changes in carbon storage in the region over time and project for the year 2030. The study also explored the impact of socio-economic and natural factors on changes in carbon storage. The results showed that： ① Between 1980 and 2020, urban construction land in the Zhejiang Central Region increased by 289.91%, with cultivated land and forest land being the main sources, leading to a 3% decrease in ecosystem carbon storage, amounting to 588.88×10⁴ tons. ② High-value areas of carbon storage in the Zhejiang Central Region were concentrated in P'an-an County, Jinyun County, Wuyi County, and other areas. ③ Under the two different scenarios of natural development and ecological protection, carbon storage in the research area was projected to decrease by 1.05% and 0.05%, respectively, by 2030 compared to that in 2020. ④ Natural factors dominated the distribution of carbon storage, but their influence was gradually decreasing over time. The impact of socio-economic factors was increasing, and the combined effect of socio-economic and natural factors far outweighed the influence of a single factor on carbon storage distribution. These findings can serve as a scientific reference and guide for mitigating carbon loss in ecosystems, promoting ecosystem protection, facilitating sustainable social development, and achieving the \"dual carbon\" goals in Zhejiang and other regions nationwide.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"5957-5969"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Characteristics of Ozone Photochemical Reaction and Emission Reduction Strategies in Summer and Autumn in Shangqiu].","authors":"Xiao-Mei Jiang, Lei-Tao Sun, Ling-Ling Wang, Sheng-Xian Hou, Li-Ya Fan, Dai-Qi Ye","doi":"10.13227/j.hjkx.202310206","DOIUrl":"https://doi.org/10.13227/j.hjkx.202310206","url":null,"abstract":"<p><p>Recently, ozone （O₃） pollution in Shangqiu has become increasingly prominent, especially in summer and autumn, crucially affecting the local environmental air quality. Based on the monitoring data of O₃ pollution days from the Environmental Monitoring Station in June and September 2022 （representing summer and autumn） in Shangqiu, an observation-based model （OBM） was used to study the causes and photochemical reaction characteristics of O₃ pollution in the city and precursor emission reduction strategies were studied. The observation results indicated that during summer in Shangqiu, the <i>ρ</i>（O₃） and O₃ daily maximum 8 h moving concentrations [<i>ρ</i>（MDA8-O₃）] were 149.7 μg·m^-3 and 195.4 μg·m^-3, whereas in autumn, <i>ρ</i>（O₃） and <i>ρ</i>（MDA8-O₃） were 119.8 μg·m^-3 and 173.9 μg·m^-3, respectively； the O₃ concentration in summer was significantly higher than that in autumn. Ozone sensitivity research showed that the generation of O₃ in summer and autumn in Shangqiu was controlled by volatile organic compounds （VOCs）. Among them, oxygen-containing volatile organic compounds （OVOCs）, aromatic hydrocarbons, and alkenes contributed the most to the ozone generation potential （OFP） and ·OH reactivity （<i>L</i>_·OH）, and the control must have been strengthened. The OBM simulation results indicated that the maximum O₃ generation rates in summer and autumn were 23.0×10^-9 h^-1 and 13.6×10^-9 h^-1, with maximum net generation rates of 17.4×10^-9 h^-1 and 10.4×10^-9 h^-1 and the maximum and maximum net generation rates of O₃ in summer were 1.68 times higher than those in autumn, indicating that the photochemical reactions in summer were significantly stronger than those in autumn. Compared with that in summer, the generation of O₃ in autumn was greatly influenced by regional inputs from other regions or cities, with a maximum input of 14.2×10^-9 h^-1. The prevention and control of O₃ pollution in the summer and autumn seasons in Shangqiu should mainly focus on controlling VOCs. The reduction ratio of VOCs/nitrogen oxides （NO<i>_x</i>） in autumn should be greater than that in summer and the reduction ratios of 3∶1 in summer and 4∶1 in autumn could be adopted for control.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"5706-5714"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Differences in Nitrogen Sources and Contributions in Shallow Groundwater in Plateau Lake Area with Different Climate Types].","authors":"Jin-Heng Min, An-Qiang Chen, Lin Li, Yuan-Hang Ye, Dan Zhang, Rong Wang","doi":"10.13227/j.hjkx.202311157","DOIUrl":"https://doi.org/10.13227/j.hjkx.202311157","url":null,"abstract":"<p><p>Clarifying the concentration, major sources, and contribution differences of nitrogen in shallow groundwater in plateau lake areas with different climate types can provide a novel direction for the control of nitrate （NO₃^-） pollution in regional groundwater. Taking the shallow groundwater around Erhai Lake in the subtropical monsoon climate zone and Chenghai Lake in the dry-hot valley area of the Jinsha River as the research objects, using hydrochemical indexes and multi-isotope techniques （<i>δ</i>¹⁵N-NO₃^-, <i>δ</i>¹⁸O-NO₃^-, <i>δ</i>¹⁸O-H₂O, and <i>δ</i>²H-H₂O） combined with the stable isotope （SIAR） model； the differences in nitrogen concentration in shallow groundwater around Erhai Lake and Chenghai Lake were analyzed, the sources of NO₃^- were identified, and the contribution rates of each pollution source were calculated. The results showed that water quality of more than 33% and 5% of shallow groundwater sampling points around Erhai Lake and Chenghai Lake was worse than the groundwater Class Ⅲ quality requirements （GB/T 14848） of 20 mg·L^-1 for nitrate nitrogen （NO₃^--N）, respectively. The <i>δ</i>¹⁸O-H₂O and <i>δ</i>²H-H₂O in shallow groundwater around Erhai Lake and Chenghai Lake were parallel to the global and Chinese atmospheric precipitation lines, and a large intercept was present, indicating that atmospheric precipitation was not the major recharge source of groundwater in the two regions. The contribution rate of different NO₃^- sources in shallow groundwater around Erhai Lake was the highest for soil organic nitrogen （53.77%）, followed by nitrogen fertilizer （21.75%） and manure and sewage （21.55%）, and atmospheric deposition nitrogen （2.93%） was the lowest. Denitrification occurred in the transformation process of nitrogen in groundwater. The contribution rate of different NO₃^- sources in shallow groundwater around Chenghai Lake was manure and sewage （44.88%） &gt; soil organic nitrogen （37.03%） &gt; nitrogen fertilizer （16.17%） &gt; atmospheric deposition nitrogen （1.92%）, and nitrification occurred in the transformation process of nitrogen in groundwater. The climate type significantly affected the shallow groundwater level, altering the migration and transformation process of nitrogen, thereby affecting the nitrogen concentration in groundwater and the contribution of NO₃^- as the chief source. However, the major source of NO₃^- was not affected by the climate type； however was more affected by land use, agricultural activities, and manure treatment methods.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"5790-5799"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of Microplastics and Straw Addition on Nitrogen and Phosphorus Leaching in Orange Orchard Soils].","authors":"Zhi-Jie Zheng, Xing-Jun Xiong, Xiu-Ling Zhang, Wei Sun, Hua Gao, Yong Zheng, Rong-Gui Hu, Shan Lin","doi":"10.13227/j.hjkx.202305199","DOIUrl":"https://doi.org/10.13227/j.hjkx.202305199","url":null,"abstract":"<p><p>To explore the effects of microplastic input and straw addition on nitrogen and phosphorus leaching in orange orchard soil, indoor soil column leaching simulation experiments were conducted on orange orchard soil in Dangyang City, Hubei Province. The experiment analyzed the effects of different treatments on the leaching characteristics of soil nitrogen and phosphorus. The results showed that： ① The increase in microplastic input increased the leaching capacity of the soil （TN, NO₃^--N, NH₄⁺-N, and TP） when only microplastic input was added. ② Under the addition of straw, the input of microplastics increased, which reduced the leaching amount of TN and NO₃^--N in the soil, and increased the leaching amount of NH₄⁺-N and TP in the soil. ③ Under the input of microplastics, the key influencing factors of soil nitrogen and phosphorus leaching were soil bulk density and water content. Under straw addition, it was mainly affected by soil carbon and nitrogen content. Among them, microplastic input and straw addition significantly increased soil pH, but their path coefficients for nitrogen and phosphorus leaching were not significantly correlated. The results showed that the effects of polypropylene microplastic input and straw addition on soil nitrogen and phosphorus leaching were related to the amount of microplastics input and whether straw was added. The results showed that the input of microplastics would increase the amount of soil nitrogen and phosphorus leaching. Although nitrogen leaching loss caused by microplastic input could be reduced under straw addition, soil phosphorus leaching loss was significantly increased.</p>","PeriodicalId":35937,"journal":{"name":"Huanjing Kexue/Environmental Science","volume":"45 10","pages":"6061-6067"},"PeriodicalIF":0.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142509629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}