长坡尾矿坝植物修复过程中土壤脲酶活性变化

Research on Changes of Soil Urease Activity during the Process of Phytoremediation in Heavy Metal Contaminated Areas of Changpo Tailing Mine Dam of Nandan County

采集广西南丹县长坡矿尾矿坝0~20 cm表土,测定了土壤pH、有机质、碱解N含量和脲酶活性。采用数理统计的相关分析方法,探究重金属污染区的植被自然恢复和植物修复过程中,土壤脲酶活性与土壤肥力水平的关系,为重金属污染区土壤的生态恢复提供理论依据。结果表明：长坡尾矿坝土壤有机质含量较低,土壤肥力状况仍然较差。土壤脲酶活性与土壤碱解氮含量之间呈正相关,与土壤有机质含量相关性不大。在尾矿坝植被自然恢复过程中,五节芒、苔草、割鸡芒等植物根际土脲酶活性的平均值相对较高,而狗牙根、类芦根际土的脲酶活性相对较低。如果不引进外来物种,只选择该尾矿坝上自然生长的植物作为生态恢复的物种,五节芒、割鸡芒和苔草等植物应作为优先选择的物种,类芦、狗牙根等植物可作为第2阶段修复的物种。

The soil＇s fertility characteristics including soil pH,organic matter content,alkali-soluble nitrogen content and the urease activity were studied in this experiment,of which the surface soil was gathered from abandoning ore dam in Changpo heavy metal contaminated area Nandan county of Guangxi. We used correlation analysis method with mathematical statistic, researching relations between the soil urease activity and the soil fertility level were studied with correlation analysis by comparing the soil urease activity in heavy metal contaminated area along with ecology recovery. The results show that the organic matter content is low,alkali-soluble nitrogen content and the urease activity are relatively high of the soil from abandoning ore dam. It shows positive correlation between urease activity and alkali-soluble nitrogen content, the correlation between urease activity and organic matter content is not significant. Along with soil ecology recovery of abandoning ore dam,the urease activity is higher of rhizosphere soil of Miscanthus floridulus, Care：c dispalata and Hypolylrum nemorurn, while it is low of rhizosphere soil of Cynodon dactylon and Neyraudia reynaudiana, we think Miscanthus floridulus, Carex dispalata and Hypolytrum nemorum are the best species for ecology recovery without introducing external species. Cynodon dactylon and Neyraudia reynaudiana can he chosen for the second stage.