黄土区土壤长期施肥对胡敏酸结构特征的影响

从黄土区长期肥料定位试验地中采集土壤样品,分离纯化胡敏酸,室内分析其化学性质、热分解特性和红外光谱特征。结果表明:长期施用化肥和有机肥均能不同程度地提高土壤胡敏酸分子的氮素含量,降低碳素含量,使其脂肪族侧链增多,芳香核结构减少,芳构化程度降低,向着简单化、年轻化方向发展。有机肥作用效果大于化肥。

EFFECT OF LONG-TERM FERTILIZATION ON THE STRUCTURAL CHARACTERISTICS OF SOIL HUMIC ACID IN LOESS AREA

Lou soil and yellow loamy soil, which occupy larger proporation of the loess area were employed in this paper. Under the condiation of long-term application of chemical and organic fertilizers, chemical pyrolytic and speotral properties of soil humic acid were studied. The results showed that long-term application of chemical or organic fertilizers, the nitrogen content of humic acid was increased while the carbon content was decreased. Soil humic acid had more aliphatic groups and fewwer aromatic groups, the degree of polymerization decreased and the molecular became simple and active. Meanwhile, the effect of organic fertilizer on humic acid was greater than that of chemical fertilizer.