添加蒙脱石是否促进白花苜蓿的腐殖化进程?  

Does Amendment of Montmorillonite Promote Humification of White Alfalfa?

作　　者：徐杨 窦森[1] 张一枫 田宇欣 段宏美 白月 XU Yang;DOU Sen;ZHANG Yifeng;TIAN Yuxin;DUAN Hongmei;BAI Yue(College of Resource and Environmental Science,Jilin Agricultural University,Changchun 130118,China)

机构地区：[1]吉林农业大学资源与环境学院,长春130118

出　　处：《土壤学报》2020年第5期1230-1239,共10页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41571231)资助。

摘　　要：植物残体和微生物生物量是腐殖物质(Humic substance,HS)形成的主要母体材料,同时黏土矿物作为土壤的重要组成部分,在HS的形成中也扮演重要角色,然而目前有关黏土矿物对HS形成过程的具体影响还不清楚。选择将黏土矿物-蒙脱石和微生物-土壤浸提液作为控制条件对白花苜蓿进行模拟培养腐殖化,通过表征培养过程中总有机碳(Total organic carbon,TOC)含量、类腐殖质组成、类胡敏酸(Humic-like acid,HLA)的元素组成和红外光谱特征,探究蒙脱石添加对白花苜蓿腐殖化进程的影响。结果表明,模拟培养腐殖化后,蒙脱石添加虽然加速了TOC的分解,促进HLA的生成,但使HLA的缩合度降低,结构简单化;而土壤浸提液添加则使蒙脱石处理加快了结构更加复杂的HLA积累。培养后,不同处理的HLA均向着接近土壤胡敏酸(Humic acid,HA)O/C和H/C值的方向发展,其中未添加蒙脱石处理(AnM)的HLA复杂化程度与真正的HA最接近,更进一步说明蒙脱石不能促进HLA更接近土壤HA。综上,在模拟培养腐殖化条件下,蒙脱石添加可促进白花苜蓿TOC的分解及其HLA的形成,从而加快白花苜蓿的腐殖化进程,但却使形成的HLA结构更加简单化,与真正的HA仍存在较大的差异,该研究结果为土壤HS的形成机理与起源探索提供了一定的科学借鉴。【Objective】Humic substances(HS),the main component of soil organic matter,are kind of macromolecular compounds,specific and multi-phased in property,formed during humification.However,in the past two decades,doubts have been arising about rationality of the disassociation process of HS.Currently,the research has shifted its focus from on chemical properties of HS to on identification of processes and mechanisms related to HS renewal and stabilization.Plant residues and microbial biomass are the main parent materials for the formation of humic substances,meanwhile,clay minerals,as an important part of the soil,also play an important role in the process.However,still little is known about any specific effects of clay minerals on formation of HS.Some scholars have used microbial pure culture methods to study formation of HS,but because of the absence of clay minerals,the formation of HS studied does not represent that in soil.Therefore,more efforts should be done to further elucidate in detail the complex interactions between HS and the surface of minerals,as well as the role of soil microbes as a participant.In order to explore effects of montmorillonite on humification process,white alfalfa,an angiosperm,was used in an incubation experiment with montmorillonite and microbe-soil extract as control conditions.【Method】In this experiment,there were three treatments,i.e.Treatment A,white alfalfa with montmorillonite and soil extract added;Treatment AnM,white alfalfa with soil extract added only;and Treatment AnI,only white alfalfa.Effects of the treatments and duration of the incuabtion on composition of humus-like substances and structure of humic-like acids(HLA)formed as incubation product of white alfalfa were studied.Water-soluble substances(WSS),fulvic-like acid(FLA),humic-like acid(HLA)and humin-like(HLu)were extracted with the modified humus composition method.HLA samples were extracted with the method recommended by the International Humic Substances Society(IHSS)for analysis of structure of HA with the

关 键 词：白花苜蓿 模拟培养 腐殖化 腐殖物质 类胡敏酸 

分 类 号：S151.9[农业科学—土壤学]