DOM是土壤中一种活跃的组分, 研究其组成、 分布和腐殖化特点对揭示土壤地球化学环境行为特征具有重要意义。 蔬菜大棚作为一种特殊的土地利用类型, 受人类活动影响较为强烈, 长期人类活动的作用会影响其土壤中DOM构成和土壤腐殖化过程的空间分布。 但关于蔬菜大棚土壤DOM特征的研究鲜见报道。 基于此, 利用三维荧光图谱技术, 结合PARAFAC模型, 解析具有长期种植年限的北方典型蔬菜种植基地土壤DOM的特征。 结果显示, 蔬菜大棚土壤DOM主要由类富里酸(C1)、 类胡敏酸(C2)和类蛋白 (C3)物质组成, 以C1组分为主。 空间分布特征显示: 在垂直方向上, 随着剖面深度的增加, C1和C2组分都明显减少, 而C3组分先增后减, DOM的腐殖化程度从0～20到30～40 cm明显降低, 到40～50 cm又有所增加; 在水平方向上, C2组分的含量在每层的空间变异均较大, C1组分在每层的空间变化均较小, C3组分介于上述二者之间, 土壤的腐殖化指数在每层的空间变异均较大。 上述结果表明, 蔬菜大棚土壤的腐殖化进程在表层较快, 此外, 腐殖化进程具有较大的空间变异特性。 本研究的意义在于: （1）通过三维荧光光谱揭示了了北方蔬菜大棚土壤DOM的组成及其空间异质性特点; （2）将PARAFAC模型用于土壤DOM的分析中, 并成功对其DOM的组分特征进行定量表征, 对土壤DOM的研究提供了新的思路。

The aim of the present work is to study the soil DOM characteristics in the vegetable greenhouse with a long-term of cultivation. Results showed that the soil DOM mainly consisted of three components, fulvic acid-like (C1), humic acid-like (C2) and protein-like (C3), with C1 as the majority one. The distribution of DOM in space was also studied. In vertical direction, C1 and C2 decreased significantly with the increase in soil depth, while C3 component decreased after increased. The humification coefficient decreased fast from 0~20 to 30~40 cm, and then increased from 30~40 to 40~50 cm. In the horizontal direction, the level of C2 component varied greatly in space, while that of C1 component changed little, and that of C3 component fell in between the above two. The change in the humification degree of each soil layer significantly varied spatially. Humification process of soil organic matter mainly occurred in the surface soil layer. In addition, the humification degree in space also changed significantly. The new ideas of this study are: (1) Analyze the composition and spatial heterogeneity of soil DOM in the vegetable greenhouse; (2) Use three dimensional fluorescence spectra technology and parallel factor analysis model successfully to quantify the components of soil DOM, which provides a new method for the soil DOM analysis.