有机物料对镉污染酸性土壤伴矿景天修复效率的影响

Effect of organic materials on phytoremediation efficiency of Cd-contaminated acid soil by Sedum plumbizincicola

伴矿景天(Sedum plumbizincicola)是一种镉/锌(Cd/Zn)超积累植物,是Cd污染土壤吸取修复的理想植物。为提高伴矿景天(S.plumbizincicola)对Cd污染酸性土壤的修复效果,本研究以水稻秸秆、大豆秸秆、猪粪和水溶性有机肥4种有机物料为材料,分别按土质量1%、3%的施用量施入Cd污染酸性农田土壤,研究了4种有机物料对伴矿景天Cd修复效率的影响。结果表明:施用有机物料可提高土壤pH值和土壤有机质、碱解N、有效P和速效K含量,有效改善供试土壤理化性质;有机物料对土壤有效态Cd含量的影响因有机物料种类和施用量而异,以3%水溶性有机肥处理效果最好,较对照提高了50.0%。与对照相比,施用有机物料显著促进了伴矿景天生长,地上部和根部生物量分别增加了1.08%~40.69%和4.17%~54.17%;水稻秸秆、大豆秸秆和水溶性有机肥处理伴矿景天地上部和根部Cd含量分别较对照增加了10.02%~64.91%和10.95%~45.78%。单一种植伴矿景天修复后土壤Cd去除率为27.6%;施用有机物料辅助修复,土壤Cd去除率可达29.8%~50.7%。因此,在Cd污染酸性土壤伴矿景天(S.plumbizincicola)修复中,可考虑水稻秸秆还田和施用水溶性有机肥来提升修复效率。

Sedum plumbizincicola is a native cadmium/zinc(Cd/Zn)hyperaccumulator,and it is an effective plant for the phytoextraction of Cd-contaminated soil.To improve phytoremediation of Cd-contaminated acid soil by S.plumbizincicola,a pot experiment was conducted to investigate the effects of four organic materials[rice straw(RS),soybean straw(SS),pig manure(PM),and dissolved organic fertilizer(OF),and their application of 1%and 3%of soil]on the phytoremediation efficiency of S.plumbizincicola.The results showed that the application of organic materials could improve the physicochemical properties of tested soil.Soil pH,organic matter,as well as available N,P,and K content,under the organic materials application treatment were higher than those of the control(CK).The effect of organic materials on soil available Cd was different due to the different kinds of organic materials and application rates,and 3%OF treatment increased the soil available Cd by 50.0%compared with the CK.The application of organic materials promoted the growth of S.plumbizincicola:shoot and root biomass,increased by 1.08%~40.69%and 4.17%~54.17%,respectively,compared with the CK.The treatments of adding RS,SS,and OF improved Cd concentration in S.plumbizincicola shoots and roots by 10.02%~64.91%and 10.95%~45.78%,respectively.Under the planting conditions of S.plumbizincicola,the soil Cd removal rate reached by CK was 27.6%,while that reached by organic material treatments was 29.8%~50.7%.Results of the present study imply that the rice straw returning and application of dissolved OF could be used as an auxiliary strengthening measure in the phytoextraction of Cd-contaminated acid soil by S.plumbizincicola.