伊犁典型草原栗钙土有机碳垂直变化规律研究

Study on the Vertical Changes of Organic Carbon in Typical Grassland Chestnut Soil in Yili

【目的】研究伊犁典型草原栗钙土有机碳总量、腐殖酸种类和腐殖质矿物复合体的不同海拔高度和土壤剖面变化规律。【方法】采用改良的B．B．HOHOMapesa法，即重铬酸钾一外加热法进行分组测定。【结果】典型草原栗钙土中有机碳总量海拔高度从869到16571TI的变化范围为9．89—47．84g/kg，其中胡敏酸（HA）含量变化范围为12．9—44．27g/k，富啡酸（FA）变化范围为15．84—32．14g／kg，而胡敏素为23．59～71．21g／k。腐殖质矿物复合体以粘土矿物复合体为主，即胡敏酸紧结合态为5．36—16．33％；而富啡酸紧结合态复合体含量较低，只占复合体总量1．06％～3．84％。腐殖质矿物复合体随土壤剖面的分布规律不论是胡敏酸还是富啡酸，均随土层深度的加深逐渐减少，即32．07、20．35、18．44、23．57、20．04和29．75g/kg。【结论】新疆典型草原栗钙土有机碳总量和腐殖质不同组分在海拔高度和土壤剖面中的含量差异都达到显著水平，且腐殖酸类型在高海拔处和剖面上层以富啡酸一胡敏酸型为主，HAZHF〉1，而低海拔处和剖面下层以胡敏酸-富啡酸型为主，HA／HF〈1。

[ Objective ] To study the variation regularity of total organic carbon, humic acid types and the mineral complex in different altitudes and soil profile of typical grassland chestnut soil. [ Method ] The im- proved B. B. method, that was, potassium dichromate - external heat- ing method in grouping determination was used in this study. [ Result] In typical grassland chestnut soil, the variation range of total organic carbon was 9. 89 -47.84 g/kg, the variation range of humic acid was 12. 9 - 44.27 g/kg, the variation range fulvic acid was 15.84 -32. 14 g/kg, and humin was 23.59 -71.21 g/kg. The main content of humus mineral complex was clay mineral complex, that was, humic acid tight bound was5.36 - 16.33% , and the content of fulvic acid tight bound was lower, which only accounted for 1.06 - 3.84% of the total complex. The mineral complex in both humic acid and fulvic acid along with the distribu- tion regularity of soil profile was gradually reduced along with the soil depth, that was 32. 07, 20.35, 18.44, 23.57, 20.04 and 29.75 g/kg. [ Conclusion] The difference of both of the total organic carbon content and different components content of humic acid of Xinjiang typical grassland chestnut soil on the altitude and in the soil profile reached the significant levels, and the main type of humus on the high altitude and in the upper profile point was fulvic acid - humie acid type, HA/HF 〉 1, and the main type of humus on the lower altitude and at the lower profile point is humic acid - fulvic acid type, HA/HF 〈 1.