Huan jing ke xue= Huanjing kexue最新文献

{"title":"[Spatial and Temporal Distribution and Influencing Factors of Dissolved Trace Metals in Jiulong River Estuary and Xiamen Bay].","authors":"Liu-Qian Qi,&nbsp;Xin-Li Yue,&nbsp;Hao-Wen Zhong,&nbsp;Qi Wang,&nbsp;De-Li Wang,&nbsp;Neng-Wang Chen","doi":"10.13227/j.hjkx.202206001","DOIUrl":"https://doi.org/10.13227/j.hjkx.202206001","url":null,"abstract":"<p><p>Trace metals play an important role in some biogeochemical processes in the marine system. The physical and hydrological conditions in estuaries and coastal seawater are complicated and significantly affected by human activities. Therefore, the biogeochemical behavior and influencing mechanism of trace metals in nearshore water have become a research hotspot. Jiulong River estuary and Xiamen Bay are located in the coastal areas of Fujian Province, which are significantly influenced by Longyan, Xiamen, and Zhangzhou City. In July 2021, November 2021, and January 2022, the trace metals chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), and cadmium (Cd) and environmental factors (water temperature, salinity, pH, dissolved oxygen (DO), suspended particulate matter (SPM), etc.) in Jiulong River estuary and Xiamen Bay were investigated. The results showed that the order of trace metal concentration average values measured in Jiulong River estuary and Xiamen Bay was Mn>Ni>Cu>Cr>Co>Cd. In July 2021, the average values of <i>ρ</i>(Cr), <i>ρ</i>(Mn), <i>ρ</i>(Co), <i>ρ</i>(Ni), <i>ρ</i>(Cu), and <i>ρ</i>(Cd) were 0.159, 47.96, 0.068, 1.56, 1.07, and 0.016 μg·L^-1, respectively. In November 2021, the average values were 0.216, 8.48, 0.030, 1.70, 1.92, and 0.019 μg·L^-1, respectively. The average concentrations in January 2022 were 0.281, 32.39, 0.062, 2.21, 1.54, and 0.034 μg·L^-1, respectively. The concentration of dissolved metals in the estuary was higher than that in the bay area. Principal component analysis showed that the main factors affecting the concentrations of dissolved trace metals were river runoff and anthropogenic activities.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 11","pages":"4939-4949"},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40722520","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 Different Fertilization Treatments on Methane and Nitrous Oxide Emissions from Rice-Vegetable Rotation in a Tropical Region, China].","authors":"Xiao-Hui Shao,&nbsp;Shui-Rong Tang,&nbsp;Lei Meng,&nbsp;Yan-Zheng Wu,&nbsp;Jin-Qiu Li,&nbsp;Guang-Lin Gou","doi":"10.13227/j.hjkx.202112213","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112213","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The study of the effects of different fertilization treatments on soil methane (CH&lt;sub&gt;4&lt;/sub&gt;) and nitrous oxide (N&lt;sub&gt;2&lt;/sub&gt;O) emissions in rice-vegetable rotation systems is of great significance to supplement the research gap on greenhouse gas emissions in tropical regions of China. In this study, four fertilization treatments were set up during the pepper season:phosphorus and potassium fertilizer application (PK); nitrogen, phosphorus, and potassium (NPK) application; half application of nitrogen, phosphorus, and potassium plus half application of organic fertilizer (NPK+M); and application of organic fertilizer (M). There was no fertilizer application during the following early rice season. The objective of our study was to investigate the rules of CH&lt;sub&gt;4&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O emissions under different fertilization treatments in the pepper growth season, and the effects of different fertilization treatments in the pepper growth season on rice yield, and CH&lt;sub&gt;4&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O emissions in the following early rice growth season. The close static chamber-gas chromatography method was applied to determine soil CH&lt;sub&gt;4&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O emissions. We measured crop yield, estimated global warming potential (GWP), and calculated greenhouse gas emission intensity (GHGI). Our results showed that:① the cumulative CH&lt;sub&gt;4&lt;/sub&gt; emission under the four fertilization treatments ranged between 0.9 kg·hm&lt;sup&gt;-2&lt;/sup&gt; to 2.7 kg·hm&lt;sup&gt;-2&lt;/sup&gt; during the pepper growth season and between 5.5 kg·hm&lt;sup&gt;-2&lt;/sup&gt; to 8.4 kg·hm&lt;sup&gt;-2&lt;/sup&gt; during the early rice growth season. Compared with NPK, NPK+M and M reduced the cumulative CH&lt;sub&gt;4&lt;/sub&gt; emission in the pepper growth season by 35.3% and 7.6%, respectively; however, NPK+M and M increased the cumulative CH&lt;sub&gt;4&lt;/sub&gt; emission in the early rice season by 37.5% and 55.1%, respectively. There was a significant difference in cumulative CH&lt;sub&gt;4&lt;/sub&gt; emission between M and NPK in the early rice growth season. ② The cumulative N&lt;sub&gt;2&lt;/sub&gt;O emission under the four fertilization treatments varied from 0.5 kg·hm&lt;sup&gt;-2&lt;/sup&gt; to 3.0 kg·hm&lt;sup&gt;-2&lt;/sup&gt; in the pepper growth season and from 0.3 kg·hm&lt;sup&gt;-2&lt;/sup&gt; to 0.5 kg·hm&lt;sup&gt;-2&lt;/sup&gt; in the early rice growth season. The cumulative N&lt;sub&gt;2&lt;/sub&gt;O emission was significantly decreased by 33.7% in NPK+M and by 16.0% in M, compared with that in NPK. In the early rice growth season, the cumulative N&lt;sub&gt;2&lt;/sub&gt;O emission was decreased by 23.5% by NPK+M but was increased by 9.1% by M. There was no significant difference in the cumulative N&lt;sub&gt;2&lt;/sub&gt;O emission among the four fertilization treatments. ③ The yields of pepper and early rice under the four fertilization treatments were 3055.6-37722.5 kg·hm&lt;sup&gt;-2&lt;/sup&gt; and 5850.9-6994.4 kg·hm&lt;sup&gt;-2&lt;/sup&gt;, respectively. Compared with that in NPK, NPK+M and M significantly increased pepper yield. The GWP under the four fertilization treatments in the pepper-early rice rotation system va","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 11","pages":"5149-5158"},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40486196","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 Soil Organic Carbon Components and Their Correlation with Other Soil Physical and Chemical Factors in Cotton Fields with Different Continuous Cropping Years in the Oasis on the Northern Edge of Tarim Basin].","authors":"Xin-Zhu Li,&nbsp;Lu Gong,&nbsp;Jun-Hu Tang,&nbsp;Yan Luo,&nbsp;Zhao-Long Ding,&nbsp;Hai-Qiang Zhu,&nbsp;Han Zhang,&nbsp;Rui-Xi Li","doi":"10.13227/j.hjkx.202110128","DOIUrl":"https://doi.org/10.13227/j.hjkx.202110128","url":null,"abstract":"<p><p>The study of soil organic carbon components in continuous cropping cotton fields in oases is helpful to reveal the change characteristics of the soil organic carbon stability mechanism in arid areas under the effects of man-land relationships. In this study, the contents of soil organic carbon, easily oxidized organic carbon, dissolved organic carbon, and microbial biomass carbon in cotton fields with different continuous cropping years (2 a, 5 a, 12 a, 20 a, and 35 a) were collected and analyzed by using space instead of the time series method. Through redundancy analysis, the relationship between soil organic carbon components and other soil physical and chemical factors was discussed. The results showed that:① continuous cropping for different years had a significant impact on the content of soil organic carbon components in the study area. The contents of soil organic carbon, easily oxidized organic carbon, dissolved organic carbon, and microbial biomass carbon in continuous cropping cotton fields for 12 a, 20 a, and 35 a were higher than those in continuous cropping cotton fields and wasteland for 2 a and 5 a. <i>ω</i>(soil organic carbon) reached the peak value (7.06 g·kg^-1) in the cotton field in 20 a, which was 76.91% higher than that in the wasteland. The content of soil organic carbon decreased with the deepening of the soil layer. ② Based on the redundancy analysis of soil organic carbon content and soil environmental factors, the results showed that the content of soil organic carbon was positively correlated with total nitrogen, available phosphorus, and water content and negatively correlated with pH value and bulk density. The importance of soil environmental factors on the interpretation of soil organic carbon content was as follows:total N>available P>pH value>bulk density>water content>available K>total salt.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4639-4647"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33500856","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":"[Spatial Differentiation and Influencing Factor Analysis of Soil Heavy Metal Content at Town Level Based on Geographic Detector].","authors":"Cang Gong,&nbsp;Liang Wang,&nbsp;Shun-Xiang Wang,&nbsp;Zhi-Xiang Zhang,&nbsp;Hang Dong,&nbsp;Jiu-Fen Liu,&nbsp;De-Wei Wang,&nbsp;Bu-Qing Yan,&nbsp;Ying Chen","doi":"10.13227/j.hjkx.202112077","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112077","url":null,"abstract":"<p><p>Geographic detectors can quickly detect spatial stratified heterogeneity and quantitatively reveal the intensity of driving factors of heavy metal content, which is of great significance for the prevention, control, and remediation of soil heavy metal pollution. In order to reveal the spatial differentiation and influencing factors of soil heavy metal content on the town-scale, 788 topsoil samples were collected from a town in the hinterland of Chengdu Plain. Soil heavy metal (Cd, Hg, As, Cu, Pb, Cr, Zn, and Ni) pollution risk assessments were carried out by using the geo-accumulation index method. Additionally, based on the geographic detector model, 15 factors such as soil properties, topography, soil forming factors, and distance were taken as independent variables, and the contents of each heavy metal element were taken as dependent variables to explore the spatial differentiation and influencing factors of heavy metal content in soils. The results showed that:the average contents of Hg, As, Pb, Cr, Cu, Ni, and Zn in the study area were 1.06-1.93 times the background value of Chengdu, and the content of Cd was lower than the background value; among them, Hg reached the light pollution level, and the other seven heavy metals were at the non-pollution level. The spatial distribution of eight heavy metals was significantly different, the correlation among the elements was significant, and a significant correlation was found between most heavy meals with soil properties; however, the correlation with distance factor and topographic factor was relatively weak. The factor detection showed that TP, TK, pH, TOC, elevation, and distance from the railway had the most significant explanatory power for the heavy metal contents. Interaction detection showed that the interaction between soil properties and other factors was the dominant factor for the spatial variation in heavy metals, and elevation, distance from residential area, distance from railways, and distance from industrial areas were also important factors. Risk detection showed that Hg had the most significant difference in the subregion of elevation and distance from railway, whereas the other seven heavy metals had the most significant difference in the sub-regions of influencing factors of soil properties. The spatial distribution of heavy metals varied significantly in soil at the town-scale, which was closely related to soil properties, topography, and human activities in the study area.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4566-4577"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501415","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":"[Phosphorus Enrichment Efficiency of CaO₂@FA Composites and the Effect of Its Recovered Material on Soil Improvement].","authors":"Wei Yue,&nbsp;Da-Peng Li,&nbsp;Ling-Yu Wu,&nbsp;Lu Wang,&nbsp;Yao-Yu Tang,&nbsp;Qi Zhu,&nbsp;Yong Huang","doi":"10.13227/j.hjkx.202112198","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112198","url":null,"abstract":"<p><p>To explore the resource utilization of phosphorus (P) in wastewater and industrial waste fly ash, we used an efficient composite material (CaO₂@FA) for phosphorus removal by loading nano-CaO₂ on the surface of fly ash as well as in the pores using the surface precipitation method. The results showed that the material had a larger specific surface area and porosity after loading CaO₂ on the fly ash surface. The specific surface area increased to 4.641 m²·g^-1, and the total pore volume was up to 0.025 cm³·g^-1. The adsorption process of CaO₂@FA on P could be described using the Langmuir isothermal adsorption model, and its maximum adsorption capacity was 185.776 mg·g^-1(20℃). The adsorption mechanism was attributed to chemical precipitation, mainly the formation of calcium hydroxyphosphate. The enrichment efficiency of CaO₂@FA composites on P was significantly higher than that of fly ash, and the efficiency was increasing with the increase in the dosage added. HCO^3- and CO₃^2- in the coexisting ions had a negative effect on P adsorption by the composites. The enrichment rate of P in domestic wastewater was up to 93% when the dosage of CaO₂@FA composites was 2.0 g·L^-1. The content of biological P in the recovered precipitates reached 1.658 mg·g^-1. The soil improvement test showed that the biological P content in soil increased by 102.9% when the recovered precipitates were added into the soil. This indicated that the operating cost of recovering 100 mg of P by this composite was as low as 0.76 yuan.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4697-4705"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501761","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 Early Rice Straw Returning with Reducing Potassium Fertilizer on Late Rice Yield and Soil Fertility].","authors":"Qiao-Yi Huang,&nbsp;Jian-Feng Huang,&nbsp;Xu Huang,&nbsp;Yong-Pei Wu,&nbsp;Ping Li,&nbsp;Hong-Ting Fu,&nbsp;Shuan-Hu Tang,&nbsp;Yi-Feng Liu,&nbsp;Pei-Zhi Xu","doi":"10.13227/j.hjkx.202112315","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112315","url":null,"abstract":"<p><p>Rice straw is an important organic fertilizer in the region for double-cropping rice in South China. To reveal the effects of early rice returning with reducing potassium fertilizer on the yield of late rice and soil fertility, field experiments were carried out in Baiyun and Huiyang district in Guangdong province. The biomass, K content, and yield of late rice and the soil fertility properties, such as soil available potassium, soil organic carbon, bacterial diversity, and bacterial community structure were analyzed under three treatments (CK, conventional fertilization; RS, straw returning with conventional fertilization; RS-K, straw returning with reducing 20% potassium fertilizer). The results showed no significant differences in the biomass and yield of late rice between the RS-K treatment and CK treatment. Compared with that in CK, the RS treatment significantly increased the K contents of rice by 3.97% (Baiyun) and 6.91% (Huiyang). The K contents of late rice under the RS-K treatment were significantly lower than that under the CK treatment during the early growth period in rice, but there was no significant difference between them during the late growth period. Compared with that in CK, the soil available K in the RS treatment increased by 13.90% (Baiyun) and 21.67% (Huiyang) (<i>P</i><0.05), and the soil available K in the RS-K treatment also increased by 3.56% (Baiyun) and 4.23% (Huiyang). Compared with that in the CK treatment, the soil dissolved organic carbon increased significantly in the RS and RS-K treatments (<i>P</i><0.05). Compared with that in CK, the straw returning treatments (RS and RS-K) significantly improved the Chao1 and Shannon indexes of soil bacteria (<i>P</i><0.05). Straw returning treatments (RS and RS-K) increased the relative abundance of Proteobacteria, Actinobacteria, and Nitrospirae compared with that in CK, whereas they decreased the relative abundance of Acidobacteria, Bacteroidetes, and Firmicutes. Redundancy analysis showed that the soil bacterial community was mainly influenced by soil organic carbon, dissolved organic carbon, microbial biomass carbon, available P, and available K. In summary, early rice returning could increase soil available K and K content in late rice. Early rice straw returning with reducing potassium fertilizer had no negative impacts on the growth and yield of late rice and could also improve soil organic carbon and the diversity of soil bacteria. Therefore, early rice straw returning with reducing potassium fertilizer can guarantee the grain yield of late rice and improve soil fertility.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4706-4715"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501762","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 and Causes of High-manganese Groundwater in Pearl River Delta During Urbanization].","authors":"Xiao-Li Lü,&nbsp;Jing-Tao Liu,&nbsp;Zhan-Tao Han,&nbsp;Liang Zhu,&nbsp;Hai-Jun Li","doi":"10.13227/j.hjkx.202111136","DOIUrl":"https://doi.org/10.13227/j.hjkx.202111136","url":null,"abstract":"<p><p>The high concentration of iron and manganese in groundwater is harmful to human health, and the sources of manganese in rapidly urbanization areas are complex. Based on more than 2500 sets of hydrochemical data in different historical periods, the spatial distribution characteristics, sources, and genesis of groundwater manganese in different aquifers and areas with different urbanization levels in the Pearl River Delta were studied by using mathematical statistics and principal component analysis. The results showed that the concentration of manganese in groundwater in the pore aquifer was obviously higher than that in the fissure and karst aquifer. The proportion of high-manganese groundwater in the pore aquifer was twice that in the fissure and karst aquifer. The proportion of high-manganese groundwater in urbanized and suburban areas was significantly higher than that in non-urbanized areas. On a regional scale, the decomposition of organic matter and the reductive dissolution of Fe-Mn (oxygen) hydroxide in sedimentary strata under reductive conditions may have been the main factors controlling the increase in manganese concentration in pore aquifers. High-manganese groundwater in fissured aquifers may have been affected by low-oxygen domestic sewage leakage accompanying urbanization and industrial wastewater leakage and infiltration accompanying industrialization. The pore high-manganese groundwater was controlled by reduction conditions, and the weakly acidic environment of fissure and karst high-manganese groundwater was the important influencing factor. In the past 10 years, the groundwater environment in the study area has been improving, and the increase in groundwater redox potential and pH was not conducive to the formation of high-manganese groundwater, which was also the main cause of the overall decrease in Mn²⁺ concentration in groundwater of different types of aquifers in the process of urbanization.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4449-4458"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33502923","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":"[Pollution and Carbon Reduction Effect of OFDI in China and Its Mechanism].","authors":"Zi-Han Bai,&nbsp;Lian-Hong Lü,&nbsp;Ming-Xuan Zhao,&nbsp;Nan Zhang,&nbsp;Hong Luo","doi":"10.13227/j.hjkx.202201283","DOIUrl":"https://doi.org/10.13227/j.hjkx.202201283","url":null,"abstract":"<p><p>Under the \"Going out\" strategy and the Belt and Road Initiatives, the trade in goods and services and flow of production factors between China and the rest of the world have become more frequent, and the total amount of outward foreign direct investment (OFDI) is considerable and growing significantly. Therefore, along with the extensive economic growth and the substantial growth of foreign investment, the environmental impact of OFDI has become noteworthy. Here, through theoretical analysis and logical deduction, three possible pathways of the impact of OFDI in China on the environment were presented as hypotheses, which included the industrial structure, the technological innovation progress, and the economic-scale expansion. Using Chinese provincial data from 2004 to 2019, an environmental load index including main environmental pollutant emissions and carbon emissions was constructed. Taking this as the dependent variable, an intermediary effect method was constructed to analyze the home pollution and carbon reduction effect and the influence mechanism of OFDI in China. The results showed that ① OFDI in China reduced the environmental load, and each 1% increase in OFDI reduced the environmental load by 0.051%-0.076%. ② The OFDI in China reduced the environmental load by advancing the industrial structure and technological innovation progress, and a 1% increase in OFDI resulted in a 0.060% and 0.006% reduction in environmental load through their indirect effects, respectively, whereas OFDI increased the environmental load by 0.009% through the path of economic-scale expansion. The contributions of leading environmental load changes mediated by advancing industrial structure, technological innovation progress, and economic-scale expansion were 65.9%-84.5%, 6.6%-8.5%, and -12.7%- -9.9%, respectively, and the contribution of OFDI directly driving the environmental load to change was 19.7%-37.4%. Based on this, policy recommendations, including promoting Chinese enterprises and capital going abroad, encouraging relatively disadvantaged domestic industries to explore foreign markets, strengthening reverse technology spillover effects, and forming a sustainable low-carbon development mode, have been proposed.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4408-4418"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33503474","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":"[Influence of Biochar Application on Soil Nitrate Leaching and Phosphate Retention: A Synthetic Meta-analysis].","authors":"Zhi-Xiang Jiang,&nbsp;Shuang Cui,&nbsp;Xin Zhang,&nbsp;Min Xi,&nbsp;De-Mao Sun","doi":"10.13227/j.hjkx.202112314","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112314","url":null,"abstract":"<p><p>How to control non-point source pollution caused by leaching of soil nitrate and phosphate from agricultural land is currently an extremely important global environmental problem facing human society. Biochar, a carbon-rich material produced from various organic feedstocks using thermochemical technologies, has attracted much attention because of its great potential in soil improvement. Many studies have been carried out to investigate the effects of biochar application on the retention, utilization, and use efficiency of soil nutrients. Unfortunately, the results from individual experimental studies regarding the effects of biochar on soil nitrate leaching and phosphate retention differed greatly. Consequently, the underlying mechanisms related to reduction in nitrate and phosphate leaching/retention by biochar application, as well as the appropriate preparation conditions (or biochar type), remain unclear. In this study, the effects of biochar application on soil nitrate leaching and phosphate retention were systematically examined using the method of Meta-analysis (MA); based on these results, the inhibition mechanisms for nitrate leaching and enhancement mechanisms for phosphate retention were also explored. In total, 149 paired datasets from 41 articles and 180 paired datasets from 36 articles were collected for nitrate and phosphate, respectively. The MA results demonstrated that, regardless biochar and soil properties, biochar application could significantly reduce soil nitrate leaching by 37.1% and increase soil phosphate retention by 20.8%. Furthermore, the C/N ratio of biochar, heating treatment temperature, and biochar application amount indicated a significant effect on the response of soil nitrate leaching to biochar application. The specific surface area of biochar, heating treatment temperature, and soil organic carbon content had a significant effect on the response of soil phosphate retention to biochar application. Based on the results from MA, the potential mechanisms of soil nitrite leaching reduction and phosphate retention enhancement were further explored from different perspectives. Lastly, the biochars prepared from straw or wood materials and pyrolyzed at a medium temperature (400-600℃) or high temperature (>600℃) were recommended for reducing soil nitrate leaching and improving soil phosphate retention, respectively. In sum, the results presented in this study can provide a scientifically theoretical basis for the practical application of biochar in the control of soil non-point source pollution of nitrate and phosphate.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4658-4668"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33500858","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 Continuous Straw Returning with Chemical Fertilizer on the Carbon Pool and Crop Yield of Rice-Rape Rotation Soils].","authors":"Ying Cai,&nbsp;Si-Wei Fu,&nbsp;Bo-Rui Zhang,&nbsp;Hong-Xiang Hu,&nbsp;Wen-Wen Liu,&nbsp;Jin-Tao Yu,&nbsp;Lin-Dong Jia,&nbsp;Yun-Feng Liu","doi":"10.13227/j.hjkx.202112042","DOIUrl":"https://doi.org/10.13227/j.hjkx.202112042","url":null,"abstract":"<p><p>According to the positioning experiment of straw returning in the continuous field 7a, the effects of straw returning combined with chemical fertilizer on soil total organic carbon (TOC), dissolved organic carbon (DOC), particulate organic carbon (POC), labile organic carbon (LOC), carbon pool management index (CPMI), and crop yield in farmland soil profiles (0-20, 20-50, and 50-80 cm) in the Chaohu Lake area were studied. There were four treatments:no straw returning+no fertilization (CK), conventional fertilization (F), straw returning+conventional fertilization (SF1), and straw returning+80% conventional fertilization (SF2). The changes in soil total organic carbon and component content, CPMI, and rape rice yield in different soil layers were analyzed. Taking CK as a reference, conventional fertilization and straw returning combined with chemical fertilizer increased the content of total organic carbon and components in the soil vertical profile, and the content of total organic carbon and components in different soil layers decreased gradually with the increase in soil depth. In the 0-20 cm soil layer, compared with that in the F treatment, the SF1 and SF2 treatments significantly increased the contents of TOC, DOC, POC, and LOC by 14.23%-28.97%, 7.86%-27.01%, 16.46%-24.24%, and 5.89%-6.64%, respectively (<i>P</i><0.05). In the 20-50 cm soil layer, the contents of TOC and LOC in SF1 were significantly increased by 9.43% and 8.34%, respectively, compared with those in the F treatment (<i>P</i><0.05), and the contents of DOC and POC in SF2 were significantly increased by 17.51% and 65.83% compared with those in the F treatment (<i>P</i><0.05). In the 50-80 cm soil layer, there was no significant difference in the contents of total organic carbon and components among the treatments. The effect of straw returning and chemical fertilizer on the soil carbon pool management index was significant. SF1 significantly improved the CPMI of the 0-50 cm soil layer compared with that in the F treatment, whereas the CPMI of the F treatment was the largest in the 50-80 cm soil layer; however, there was no significant difference among all treatments. Straw returning combined with chemical fertilizer had a significant effect on crop yield, and the yield of the SF1 treatment was the highest; compared with that of the F treatment, the rice, rape, and annual yields were significantly increased by 6.19%, 7.67%, and 6.54%, respectively (<i>P</i><0.05). In general, straw returning combined with chemical fertilizer was of great significance to improve the soil carbon pool, soil fertility, and crop yield in the Chaohu Lake area.</p>","PeriodicalId":172067,"journal":{"name":"Huan jing ke xue= Huanjing kexue","volume":"43 10","pages":"4716-4724"},"PeriodicalIF":0.0,"publicationDate":"2022-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33501763","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}