论文部分内容阅读
岩溶区石灰土是在热带、亚热带地区碳酸盐岩类经溶蚀风化后的产物,岩溶区石灰土具有富钙偏碱的地球化学特点,但是岩溶区石灰土中钙的形态特征尚不清楚。为研究岩溶区土壤钙的形态随季节变化特征,在丫吉岩溶试验场不同地貌部位采集土壤样品,采用BCR方法,分析和探讨了土壤中钙的形态特征及其随季节的迁移特征。结果表明:(1)总体上,研究区土壤总钙平均含量为5.25±0.68 g kg-1,各形态钙所占总钙的比例大小顺序为酸溶态>可还原态>残渣态>可氧化态;并且除可氧化态钙之外,其余钙形态与土壤总钙均呈极显著的正相关关系(P<0.01);(2)从季节上看,基本均表现为随着四季的更替,逐渐降低,但除残渣态钙随季节变化差异显著外,总钙和其余钙形态在季节上的差异不显著;(3)从地貌上来看,总钙和各形态钙含量均表现为坡地最大,并且坡地与其它地貌部位的差异性显著(P<0.05),而平原、垭口和洼地的各形态钙之间的差异不显著(P>0.05)。
Karst limestone is the product of carbonate weathering and erosion in the tropical and subtropical regions. The calcareous limestone in the karst region is geochemically rich in calcium and alkali, but the morphological characteristics of limestone in the karst region are not yet clear. In order to study the morphological changes of soil calcium in the karst area with seasonal variations, soil samples were collected from different geomorphological sites in the Yaji karst test site. The BCR method was used to analyze and discuss the morphological characteristics of calcium and their migration characteristics with the seasons. The results showed that: (1) In general, the average content of total calcium in soil was 5.25 ± 0.68 g kg-1, and the proportion of total calcium in each form was acid-soluble> reducible> residual> oxidizable (P <0.01). (2) From the point of view of season, all of the remaining calcium forms showed a significant positive correlation with total soil calcium (P <0.01) But there was no significant difference in the total calcium and other calcium forms except for the difference of the residual calcium with the seasons; (3) From the geomorphological point of view, the total calcium and all forms of calcium showed the largest slope, (P <0.05), while there was no significant difference (P> 0.05) between various forms of calcium in plain, pass and depression.