土壤学报2017，Vol.54Issue(6)：1451-1458,8.DOI:10.11766/trxb201704270011
土壤微团聚体中矿物-有机复合体特征
Characterization of Mineral-organic Complex in Soil Microaggregates with Synchrotron Radiation Infrared Micro-imaging Method
摘要
Abstract
[Objective]In this study,the synchrotron radiation infrared micro-imaging method was used to characterize mineral-organic complex in soil microaggregates of the red soils under long-term application of organic manure or chemical fertilizer in the long-term stationary experiment station of the national soil fertility network in Qiyang,Hunan,China.[Method]Soil samples were collected from the long-term experiment station for fractionation of soil microaggregates using the dry sieving method. The obtained soil microaggregates were spread over on a Whatman GF/A Filter,mounted onto a sieve and fixed to a chimney funnel that transferred warm mist from a humidifier filled with ultrapure water. Excess droplets on the filter were drained. Then the soil microaggregates were frozen at -20 ℃ and directly cut into thin sections (300~600 nm)on an ultramicrotome using a diamond knife. Sections were transferred to infrared-reflecting MirrIR Low-E microscope Slides.[Result]Results show that clay minerals(3620 cm-1)and larger molecular organics(i.e.,lipids,2920 cm-1;proteins,1650 cm-1;and polysaccharides,1080 cm-1) were distributed in a pattern highly heterogeneous. However,among them clay minerals and polysaccharides were quite similar in distribution pattern,but differed sharply from lipids and proteins. Compared to the soil under long-term chemical fertilization,the soil under long-term application of organic manure had clay minerals and larger molecular organics distributed in soil microaggregates with higher dispersivity. Furthermore,in terms of determination coefficient(R2)with clay minerals,the organic functional groups followed an order of lipid> polysaccharide> protein in both soils,suggesting that affinity of clay minerals with larger molecular organics varied in soil microaggregates,and was not affected by fertilization of either chemical or organic. Meanwhile,the synchrotron radiation microzone infrared spectra further demonstrated that characteristic peaks of both clay minerals and larger molecular organics increased in intensity from the outer to the inner of the soil microaggregates.[Conclusion]In summary,the synchrotron radiation infrared micro-imaging method provides a novel research means and useful information to the study on characterization of mineral-organic complexes in soil microaggregates.关键词
土壤团聚体/黏土矿物/有机物/矿物-有机复合体/同步辐射红外显微成像Key words
Soil aggregate/Clay minerals/Organics/Mineral-organic complex/Synchrotron radiation infrered micro-imaging technique分类
农业科技引用本文复制引用
褚冰杰,余光辉,刘飞飞,沈其荣,冉炜..土壤微团聚体中矿物-有机复合体特征[J].土壤学报,2017,54(6):1451-1458,8.基金项目
国家自然科学基金面上项目(41371248)和国家重点研发计划重点项目(2017YFD0800803)资助 Supported by the National Natural Science Foundation of China(No. 41371248)and the National Key Research and Development Program of China(No. 2017YFD0800803) （41371248）
