土壤腐殖质分组研究

Studies on Fractionation of Soil Humus

采用Pallo法对两种耕地土壤腐殖质进行分组,初步研究了各组分的数量和结构特征。结果表明:焦磷酸钠提取的胡敏酸(HAp)是胡敏酸(HA)的主要组分;游离富里酸(FAf)是富里酸(FA)的主要组分;胡敏素(HM)的主要组分为非溶解性胡敏素(ISHM),而溶解性胡敏素(SHM)含量较低。通常随土层深度增加,HA、HM各组分的绝对数量和相对数量都下降;FA各组分的绝对数量也下降,而相对数量增加;HA/FA比值下降。一般来看,焦磷酸钠提取的富里酸(FAp)、氢氧化钠提取的富里酸(FAs)比相应的HAp、氢氧化钠提取的胡敏酸(HAs)的分子结构简单,铁结合胡敏素(HMi)比粘粒结合胡敏素(HMc)的分子结构简单;随土层深度增加,HAp、HAs的分子结构变简单,而HMi、HMc的分子结构变复杂。

The contents and structural characteristics of humus fractions from two cultivated soils were primarily studied by Pallo method. The results showed that Na_4P_2O_7-extractable humic acid (HAp) was the main component of humic acid (HA), free fulvic acid (FAf) was the main component of fulvic acid (FA), and insoluble humin (ISHM) was the main component of humin (HM). With the increase of soil depth, HA/FA ratio decreased. In general, Na_4P_2O_7-extractable fulvic acid (FAp), NaOH-extractable fulvic acid (FAs) and iron-bound HM (HMi) were simpler than HAp, NaOH-extractable humic acid (HAs) and clay-bound HM (HMc) in their molecular structure, respectively.With the increase of soil depth, the molecular structure of HAp and HAs became simpler and that of HMi and HMc became more complex.