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Effects of Fe3+ and Ca2+ on sorption of phenanthrene by humin in karst soil,Southwest China

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Acta Geochimica 2023年第1期42卷 125-135页

作者： Xianjin An Wei Li Xinyue Di Jiacheng Lan School of Karst Science Guizhou Normal University550001 GuiyangChina State Engineering Technology Institute for Karst Desertifi cation Control 550001 GuiyangChina Guiyang University 550005 GuiyangChina School of Geography and Environmental Engineering Gannan Normal University341000 GanzhouChina

humin(HM) is the main organic matter component to af fect the migration and transformation of polycyclic aromatic hydrocarbons(PAHs) in soil. The study on infl uence of the morphology change of inorganic ions on the adsorption of PAHs in soil and its organic matter is still rare at microscopic scale. In this paper, yellow soil humin(YS-HM) and lime soil humin(LS-HM) were chosen as samples, then Fe^(3+) and Ca^(2+) were added into samples to facilitate the precipitation by changing the existing conditions of ions, and the mechanism by which inorganic precipitation changed adsorption capacity of karst soil was analyzed from the microscopic scale. The results showed that the adsorption capacity of HM reduced with the inorganic precipitation increasing. The precipitation of Ca^(2+)and Fe^(3+) both reduced the adsorption capacity of YS-HM and LS-HM by 61.71% and 71.83% on average, respectively. The results of scanning electron microscope-energy dispersive spectrometry(SEM-EDS) and pore analysis showed that the HM porosity decreased after formation of Ca^(2+) and Fe^(3+) precipitation. According to the value of Freundlich parameter n, it may be because the precipitation or colloid of Ca^(2+) and Fe^(3+) fi lled micropores and covers high-energy adsorption sites of the HM. This research provides theoretical support for studying the PAHs migration and bioavailability of Calcium-rich in karst soil.

关键词： Inorganic ions humin Phenanthrene Adsorption Soil Karst

Solid-State 13C Nuclear Magnetic Resonance Spectroscopic Characterization of Soil Organic Matter Fractions in a Forest Ecosystem Subjected to Prescribed Burning and Thinning

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Pedosphere 2017年第5期27卷 901-911页

作者： thilini d.ranatunga zhongqi he kamala n.bhat junyan zhong Department of Biological&Environmental Sciences Alabama A&M UniversityNormal AL 35762(USA) USDA-ARS Southern Regional Research CenterNew 0rlcans LA 70124(USA) Department of Physics Chemistry and MathematicsAlabama A&M UniversityNormal AL 35762(USA) College of Sciences 0ld Dominion UniversityNorfolk VA 23529(USA) Intertek Allentown PA 18195(USA)

Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.

关键词： density fractionation forest fires forest management practices forest soils fulvic acids humic acids humin particulateorganic matter

Carbon Sequestration in Soil Humic Substances Under Long-Term Fertilization in a Wheat-Maize System from North China

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Journal of Integrative Agriculture 2014年第3期13卷 562-569页

作者： SONG Xiang-yun LIU Shu-tang LIU Qing-hua ZHANG Wen-ju HU Chun-guang College of Resources and Environment Qingdao Agricultural University Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences

The changes in humic substances （HS） is fundamental in detecting soil carbon sequestration mechanisms in natural and cultivated environments. Based on a long-term trial, the amounts of water dissolved substances （WSS）, humic acid （HA）, fulvic acid （FA） and humin （HU） were determined to explore the impact of long-term fertilization on HS. Increases in the amounts of WSS, HA, FA and HU were significant different among the treatments with manure. A significant correlation was found between the increased soil organic carbon （SOC） and HS （R^2=0.98, P〈0.01）. The change in the E4/E6 ratio was significantly correlated with the increased SOC （R2=0.88, P〈0.01）, HA （R^2=0.91, P〈0.01）, FA （R^2=0.91, P〈0.01） and HU （R^2=0.88, P〈0.01）. The cluster was mainly divided into two parts as manure fertilization and inorganic fertilization, based on the increases in HA, FA and HU. These results suggest that long term fertilization with manure favours carbon sequestration in HS and is mainly stabilized as HU, while the HA becomes more aliphatic. We conclude that increases in SOC can be linked to changes in the molecular characteristics of HS fractions under long term fertilization.

关键词： carbon sequestration humic acid humin long term fertilization E4/E6 ratio

Humic substances:Structure,function and benefits for agroecosystems—a review

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Pedosphere 2023年第2期33卷 237-249页

作者： Jaya TIWARI AL RAMANATHAN Kuldeep BAUDDH John KORSTAD Department of Community Medicine and School of Public Health Postgraduate Institute of Medical Education and ResearchChandigarh 160012(India) Skill faculty of Applied Sciences and Humanities Shri Vishwakarma Skill UniversityPalwal Haryana 121102(India) School of Environmental Sciences Jawaharlal Nehru UniversityNew Delhi 110067(India) Department of Environmental Sciences Central University of JharkhandRanchi 835205(India) Department of Biology and Global Environmental Sustainability Oral Roberts UniversityTulsa OK 74171(USA)

The increasing global demand for food production,often causing excessive use of chemical fertilizers,has led to the deterioration of soil *** action is required to restore soil health in a sustainable *** review advocates switching to use of organic matter(manure and compost)that contains vital nutrients for plant growth and helps restore soil *** substances(HSs),derived from degraded plant remains and found ubiquitously in nature,are an important source of organic *** application of HSs to soil enhances essential nutrient supply and assimilation of atmospheric CO_(2)due to increasing biomass *** HS application globally can help lower atmospheric CO_(2)concentrations and create a sustainable agricultural ***,the process of humification and the molecular structure of HSs remain poorly understood subjects in soil ***,it is imperative to understand the mechanisms underlying various roles of HSs in *** review offers an insight into the various structural and functional aspects of HSs,particularly fulvic acid and humic *** dynamic and interactive nature of HSs creates a framework for sustainable agriculture.

关键词： fulvic acid humic acid humin humus nutrient supply soil health sustainable agriculture

Latitudinal patterns and influencing factors of soil humic carbon fractions from tropical to temperate forests

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Journal of Geographical Sciences 2018年第1期28卷 15-30页

作者：徐丽王春燕朱剑兴高扬李美玲吕瑜良于贵瑞何念鹏 Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS College of Resources and Environment University of Chinese Academy of Sciences Branch of Experimental School of Beihang University College of Geographical Science Southwest University

Soil humic carbon is an important component of soil organic carbon （SOC） in ter- restrial ecosystems. However, no study to date has investigated its geographical patterns and the main factors that influence it at a large scale, despite the fact that it is critical for exploring the influence of climate change on soil C storage and turnover. We measured levels of SOC, humic acid carbon （HAC）, fulvic acid carbon （FAC）, humin carbon （HUC）, and extractable humus carbon （HEC） in the 0-10 cm soil layer in nine typical forests along the 3800-km North-South Transect of Eastern China （NSTEC） to elucidate the latitudinal patterns of soil humic carbon fractions and their main influencing factors. SOC, HAC, FAC, HUC, and HEC increased with increasing latitude （all P〈0.001）, and exhibited a general trend of tropical 〈 subtropical 〈 temperate. The ratios of humic C fractions to SOC were 9.48%-12.27% （HAC）, 20.68%-29.31% （FAC）, and 59.37%-61.38% （HUC）. Climate, soil texture, and soil microbes jointly explained more than 90% of the latitudinal variation in SOC, HAC, FAC, HEC, and HUC and interactive effects were important. These findings elucidate latitudinal patterns of soil humic C fractions in forests at a large scale, and may improve models of soil C turnover and storage.

关键词： humic acid carbon humin latitude pattern soil organic carbon NSTEC