不同比例有机无机肥配施土壤腐殖质组分的光谱学特征

Spectroscopic Characteristics of Soil Humus Components Under Different Proportions of Organic and Inorganic Fertilizers

以16年长期定位试验为基础,探讨不同比例有机无机肥配施对土壤腐殖质特征的影响。通过分离纯化腐殖质中的胡敏酸(HA)和富里酸(FA)组分,并利用元素分析、红外光谱和核磁共振研究分析了F1(70%化肥+30%有机肥)、F2(50%有机肥+50%化肥)和F3(100%有机肥)三种施肥方式下的HA和FA含量及结构变化。结果表明,F3对于提升HA和FA含量的效果优于F1和F2处理,说明有机肥的施用量越高,土壤腐殖质组分的含量就越高。元素分析表明,不同配比的有机无机肥对HA和FA各元素含量及原子比影响不同。F2和F3都提高了HA的缩合度,降低了氧化度和极性,其中F3的效果更加明显;有机肥的施用还能促进HA中含氮化合物的形成,并且在F2中的效果最好;有机肥的施用同样提高了FA的缩合度而降低了氧化度和极性并促进了含氮化合物的形成,尤其在F2处理中尤为明显。腐殖质红外光谱分析表明,与F1相比,F2和F3提高了HA中脂肪族化合物、碳水化合物物质的含量,FA的羧基基团、脂肪基团含量也增加,且在F3处理中表现最为显著;F2处理则降低了HA中脂肪烃物质的含量,FA中的碳水化合物则达到最高。13 C核磁共振波谱分析显示,在三种处理中,有机肥的施用提高了HA和FA的脂化度而降低其芳化度,其中F2处理中HA官能团变化更加显著,FA在F3处理中则变化更加明显。综上所述,有机肥显著提高了土壤腐殖质组分含量,并且提高了HA和FA的脂化度降低其芳化度,但是不同用量有机肥下HA和FA的形成机制不同。

This study explored the effects of different proportions of organic and inorganic fertilizers on soil humus characteristics based on the 16-year long-term localization experiment.The humic acid(HA)and fulvic acid(FA)components in the humus are separated and purified,and studied the changes of HA and FA contents and structure utilized chemical analysis and various spectroscopy techniques under three fertilization of F1(70%chemical fertilizer+30%organic fertilizer),F2(50%organic fertilizer+50%chemical fertilizer)and F3(100%organic fertilizer).The results showed that the effect of F3 on improving HA and FA content was better than that of F1 and F2 treatments,indicating that the higher application rate of organic fertilizer,the higher content of soil humus components.Elemental analysis showed that different ratios of organic and inorganic fertilizers had different effects on the content and atomic ratio of HA and FA.F2 and F3 both increase the degree of HA condensation,reduce the degree of oxidation and polarity,and the effect of F3 is obvious;the application of organic fertilizer can also promote the formation of nitrogen compounds in HA,and the effect is the best in F2;The application of organic fertilizer also increased the degree of condensation of FA,reduced the degree of oxidation and polarity,and promoted the formation of nitrogen-containing compounds,especially in the F2 treatment.Infrared spectroscopy analysis of humus showed that compared with F1,F2 and F3 increased the content of aliphatic compounds and carbohydrates in HA,and the carboxyl group and fat group content of FA also increased,and it was the most significant in F3 treatment.F2 treatment reduced the content of fatty hydrocarbons in HA,and the carbohydrates in FA reached the highest.13 C NMR spectroscopy analysis showed that the application of organic fertilizer increased the degree of aromatization of HA and FA and decreased the degree of aromatization in the three treatments,and the change of HA functional group in F2 treatment was significant,FA changed more obvious in F3 treatment.In summary,organic fertilizer significantly increased the content of soil humus components and increased the degree of aromatization of HA and FA,but the formation mechanism of HA and FA under different amounts of organic fertilizer was different.