石灰性母质对土壤腐殖质组成和性质的影响

本文研究了采自泰安、南京、昆明3地在相近植被类型下的石灰性土壤和非石灰性土壤的腐殖质组成和胡敏酸的结构特征。结果表明,和同一地区的非石灰性土壤相比,石灰性土壤不但胡敏酸/富里酸比值恒较高,活性胡敏酸的相对含量显著较低,且其胡敏酸的芳化度和羧基含量较高,全氮及酰胺态氮的含量较低。看来,土壤呈微碱性反应不仅有利于有机物质腐解过程的进行,而且有利于游离基的形成,从而有利于酚类物质相互之间以及酚类物质与含氮化合物之间的缩聚反应和腐殖酸的脱胺作用的进行。

EFFECT OF CALCAREOUS PARENT MATERIALS ON THE COMPOSITION AND CHARACTERISTICS OF SOIL HUMUS

Pairs of calcareous and non-calcareous soils under similar vegetation were collected from Taian, Nanjing and Kunming districts and the fractional composition of humus and structural characteristics of humic acids of these soils were studied. Results showed that. the HA/FA ratio of calcareous soil was consistently higher and the relative content of mobile HA was significantly lower than those of non-calcareous soils in the same location. Moreover, the humic acid extracted.from the calcareous soil was hjgher in aromaticity and content of carboxyl group and lower in contents of total nitrogen and amide nitrogen as compared with that extraded from the non-ealcareous soil. It seems that the chemical environment of calcareous soil is favorable not only for the decomposition of organic matter, but also for the polycon-densation of phenolic compounds with nitrogen-containing compounds, as well as the deamination of humic acids.