长期施肥下黑土团聚体中溶解性有机质的光谱特征及其对有机碳矿化的影响  

Spectral Characteristics of Dissolved Organic Matter in Black Soil Aggregates Under Long-Term Fertilization and Its Impact on Organic Carbon Mineralization

作　　者：朱园辰 张敏 韩晓增[1] 陆欣春[1] 冯浩亮 武志民 陈旭[1] 严君[1] 邹文秀[1] 王伟 ZHU Yuan-chen;ZHANG Min;HAN Xiao-zeng;LU Xin-chun;FENG Hao-liang;WU Zhi-min;CHEN Xu;YAN Jun;ZOU Wen-xiu;WANG Wei(Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Harbin 150081,China;Heilongjiang Academy of Black Soil Conservation and Utilization,Harbin 150086,China)

机构地区：[1]中国科学院东北地理与农业生态研究所,黑龙江哈尔滨150081 [2]黑龙江省黑土保护利用研究院,黑龙江哈尔滨150086

出　　处：《光谱学与光谱分析》2025年第5期1432-1439,共8页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2022YFD1500100);中国科学院战略性先导科技专项A类(XDA28070100);财政部和农业农村部:国家现代农业产业技术体系(CARS-04)资助。

摘　　要：探究团聚体中溶解性有机质(DOM)的荧光特征对土壤有机碳(SOC)矿化的贡献。基于黑土22年有机肥定位试验,设置不施肥(CK)、化肥(CF)、化肥配施低量有机肥(OM1)、化肥配施中量有机肥(OM2)、化肥配施高量有机肥(OM3)5个处理。采用湿筛法测定了土壤水稳性团聚体的分布,利用三维荧光光谱耦合平行因子(EEM-PARAFAC)技术探究了团聚体中DOM的荧光结构演变特征,同时量化了全土中SOC的矿化能力,综合揭示长期施肥如何通过改变团聚体DOM的荧光特征以影响全土SOC的矿化。结果表明,与CK相比,长期化肥配施有机肥使>0.25 mm粒径团聚体占比显著提升了4.3%~11.9%,而<0.053 mm粒径团聚体的占比几乎不受影响。EEM-PARAFAC发现化肥配施有机肥可以提升各粒径团聚体DOM中的类富里酸、类蛋白质和类胡敏酸组分的荧光强度。其中,类胡敏酸和类蛋白质组分分别在>0.25 mm和<0.25 mm团聚体DOM中对有机肥响应最强烈。化肥配施有机肥后各粒径团聚体DOM的自生源特征(BIX>1.0)较CK显著加强(BIX<0.8),但荧光指数(FI)和腐殖化指数(HIX)变化不显著。此外,化肥和化肥配施有机肥均可以显著提升全土SOC的累积矿化量,提升效果符合OM3>OM2>OM1>CF>CK的规律,在培养结束时(28 d)较CK提升了68.2%~135.8%。Mantel试验和结构方程模型(SEM)表明,各粒径团聚体DOM的荧光结构变化均会影响SOC的矿化,其中BIX值的变化是主要诱导因子,而BIX的强弱主要受DOM中的类蛋白质组分所控制。此外,施肥主要通过改善>0.25 mm团聚体的粒径分布驱动全土SOC矿化,而<0.25 mm团聚体主要通过改变DOM的荧光结构以影响SOC的矿化。该研究结果表明团聚体的粒径分布,DOM的荧光特征,尤其是BIX指数也可以用来推测SOC的矿化能力,这为评估和预测有机肥长期施用后黑土碳排放提供科学依据。Exploring the contribution of fluorescence characteristics of dissolved organic matter(DOM)in aggregates to soil organic carbon(SOC)mineralization.Based on a 22-year organic fertilizer positioning experiment on black soil,set no fertilization(CK);chemical fertilizer(CF);low amount of organic fertilizer(OM1)added to chemical fertilizer;moderate amount of organic fertilizer(OM2)added to chemical fertilizer;and high amount of organic fertilizer(OM3)added to chemical fertilizer.The composition of soil water-stable aggregates was determined using the wet sieving method,and the spectral characteristics of DOM in the aggregates were investigated using three-dimensional fluorescence spectroscopy coupled with parallel factor(EEM-PARAFAC)technology.At the same time,the mineralization ability of the bulk soil was quantified.Comprehensively revealing how long-term fertilization affects the mineralization of SOC in the whole soil by changing the fluorescence characteristics of aggregate DOM.The results showed that compared with CK,the proportion of particle size aggregates>0.25 mm under the combination of organic fertilizer and chemical fertilizer significantly increased by 4.3%~11.9%.In comparison,the proportion of aggregates with a particle size of<0.053 mm was almost unaffected.EEM-PARAFAC found that combining chemical fertilizers and organic fertilizers can enhance the fluorescence intensity of fulvic-like,protein-like,and humic-like components in various particle-size aggregates of DOM.Among them,humic-like and protein-like components showed the strongest response to organic fertilizers in aggregates of>0.25 mm and<0.25 mm DOM,respectively.Moreover,compared to CK(BIX<0.8),the autotrophic characteristics of DOM in different particle size aggregates were significantly enhanced(BIX>1.0)after the application of chemical fertilizers and organic fertilizers.Still,the fluorescence index(FI)and humification index(HIX)changes were insignificant.In addition,the mineralization ability of SOC increases with the application of organi

关 键 词：溶解性有机质 长期施肥 团聚体 平行因子 荧光指数 

分 类 号：S153.6[农业科学—土壤学]