滇池流域土壤活性腐殖质及其主要组分的紫外-可见与三维荧光光学特性

利用紫外-可见光谱和三维荧光光谱技术,结合土壤腐殖质及腐殖质组分(胡敏酸、富里酸)中的有机碳含量,研究了滇池流域土壤活性腐殖质及其组分胡敏酸和富里酸的光谱特征.结果表明,滇池流域土壤活性腐殖质中富里酸含量高于胡敏酸,流域范围内土壤活性腐殖质及其组分含量分布不均匀,活性腐殖质、胡敏酸和富里酸含量的变异系数分别达37.7%、36.4%、40.9%.土壤活性腐殖质及其组分胡敏酸和富里酸的碳含量均表现为菜地荒地草地湿地.光谱特征结果表明,滇池流域土壤活性腐殖质主要由自生源物质和经一定程度降解后的外源物质共同组成.此外,自生源性与光化学及生物活性具有正相关关系.因此,具有弱自生源性的滇池流域土壤活性腐殖质所具有的光化学和生物活性较弱.

Ultraviolet-visible and three-dimensional fluorescence spectroscopy characteristics of soil active humus and its main compositions at Dianchi Lake basin

Soil samples at Dianchi Lake basin were collected in July 2014 and measured by ultraviolet-visible absorption spectroscopy and three-dimensional fluorescence spectroscopy (3DEEMs) in combination with carbon concentration. Based on these measured data, the spectrum characteristics of soil active humus as well as its compositions of humic acid and fulvic acid were studied. The results indicated that soil active humus in Dianchi Lake basin contained much more fulvic acid than humic acid. The distribution of soil active humus and its compositions were heterogeneous in this region, with the variation coefficient of soil active humus, humic acid and fulvic acid of 37.7%, 36.7% and 40.9%, respectively. The carbon concentration of active soil humus, humic acid and fulvic acid were in the same order of vegetable field < wasteland < grassland < wet land. The formation of active soil humus consisted of endogenous substances and partly degraded exogenic substances. A positive correlation between photochemical activity and endogenous characteristic was found in our study. Therefore, the photochemical and bio-availability activity in soil active humus was weak due to its weak endogenous characteristic in Dianchi Lake basin.