秦岭火地塘林区不同土壤类型腐殖质组成及结合态腐殖质特性的研究

A Research on Humus Components and Attributes of Binding Humus in Different Types of Soil at Huoditang Forest Region in the Qinling Mountains

对秦岭火地塘林区棕壤、暗棕壤及草甸土进行了分析测定。结果表明，不同土类在腐殖质组成及结合态腐殖质特性方面存在明显差异。棕壤、暗棕壤及草甸土的Ｈ／Ｆ值相比较，以暗棕壤最大，草甸土次之，棕壤最小；随剖面加深３种土类的Ｈ／Ｆ值明显下降。除草甸土、暗棕壤Ａ层外３种土类腐殖质均以富里酸为主。３种土类的结合态腐殖质均以松结合态为主，且以草甸土相对含量最高，暗棕壤次之，棕壤最低；随剖面加深，棕壤、暗棕壤及草甸土结合态腐殖质相对含量有增大趋势。３种土类的土壤有机质绝大部分是以结合态形式存在。

The results obtained by analysing brown soil, dark brown soil and meadow soil in the Qinling Mountains indicated that they were obviously different in humus components and attributes of binding. The H/F ratio is the highest for dark brown soil, while the smallest for brown soil and intermediate for meadow soil. On the other hand, the H/F ratioes of all soils decrease obviously with the depth of the soil profile. Fulvic acid is the main component among various humus components except layer A of meadow soil and dark brown soil, and the binding forms of humus contented in three soils are mostly loose forms, of which content is highest, intermadiate and lowest for medaow soil, dark brown soil and brown soil, respectively, and its content also increase with the depths of soil profile. The soil organic matter in three soils mostly exists in binding forms.