土壤紧实度对伴矿景天生长及镉锌吸收性的影响研究

Effects of Soil Compaction on Phytoextraction of Cadmium and Zinc Polluted Soils by Sedum plumbizincicola

采集黏土、壤黏土和砂质壤土,分别设置无压实、低紧实度及高紧实度3种处理,通过盆栽试验研究了土壤紧实度对Cd、Zn超积累植物伴矿景天生长和Cd、Zn吸收性的影响。结果表明,与无压实处理比较,砂质壤土、壤黏土和黏土中伴矿景天地上部生物量在低紧实度下显著下降66.8%~83.5%、59.9%~60.4%和57.9%~71.4%;高紧实度处理却显著提高了伴矿景天的根系活力(142%~241%)。高紧实度处理显著降低了壤黏土上伴矿景天地上部Cd和Zn含量,但低紧实度对砂质壤土和黏土上伴矿景天地上部Cd和Zn含量无显著影响。与无压实处理比较,低紧实度显著降低了砂质壤土、壤黏土和黏土上伴矿景天的Cd吸取量,分别下降50.4%~73.8%、61.4%~74.9%和43.4%~63.3%,Zn吸取量下降48.7%~79.5%、73.6%~79.0%和46.1%~63.5%;土壤紧实度对壤黏土上伴矿景天的镉锌吸取效率影响最明显。

A pot experiment was conducted to study the effects of soil compaction on the growth of Sedum plumbizincicola and its uptake of cadmium（Cd） and zinc（Zn）. Soils of different textures（clay, loamy clay and sandy loam） were treated respectively with no compaction, low-level compaction and high-level compaction. In comparison to no compaction, soil compaction resulted in significant decreases in shoot biomass of Sedum plumbizincicola by 66.8%–83.5%, 59. 9%–60.4% and 57.9%–71.4% in sandy loam, loamy clay and clay soils, respectively. However, the root activity was significantly improved by 142%–241% under high compaction treatment. In clay loam soil, high compaction resulted in significant decreases in Cd and Zn contents of shoot biomass. However, in sandy loam and clay soils, soil compaction had no significant effects on Cd and Zn contents of shoot biomass. In the respective sandy loam, loam clay and clay soils, soil compaction significant decreased Cd uptakes by 50.4%–73.8%, 61.4%–74.9% and 43.4%–63.3%, Zn uptakes by 48.7%–79.5%, 73.6%–79.0% and 46.1%–63.5%, respectively. Overall, soil compaction has the largest impacts on inhibiting the efficiencies of Cd and Zn uptakes by Sedum plumbizincicola in loam clay soil in the presenting study.