东南景天与甜玉米套种对镉污染农田修复效果研究

Study on Remediation Effects of Sedum alfredii Hance and Sweet Corn Intercropping on Cadmium-Polluted Farmland

为了研究套种模式下镉超积累植物东南景天对农田重金属的提取效率,以华南农业大学提供的东南景天种苗和广州市农科院提供的‘广彩甜糯3号’为供试品,采用东南景天与甜玉米套种技术,在广东省惠州市公庄镇开展了中度镉污染农田修复试验。结果表明:套种模式下甜玉米产量不仅增加,籽粒Cd含量显著下降,与单一种植模式相比,玉米籽粒Cd下降了8.3%。另外,套种模式下,东南景天的生物量增加了16.5%,根部和地上部的Cd积累量分别增加了8.8%和3.6%,富集系数分别提高了15.7和6.6个单位。甜玉米与东南景天套种后,表层土壤Cd含量显著下降。研究发现,东南景天与甜玉米套种的植物修复模式,可以促进玉米植株的生长,且能有效降低玉米籽粒中Cd的含量,同时能实现污染耕地的边治理边生产,提高修复植物东南景天对Cd的提取效率,对于中度重金属污染农田防治来说是一种切实可行的绿色修复技术,具有一定的推广价值。

To investigate the efficiency of Sedum alfredii in extracting heavy metals from farmland under intercropping systems,this study employed the technique of intercropping the Cd-hyperaccumulator Sedum alfredii with sweet corn to conduct experiments in moderately cadmium-contaminated farmland in South China.The results indicated that under the intercropping system,the yield of sweet corn increased,and the Cd content in the kernels significantly decreased by 8.3%compared to monoculture.Additionally,under the intercropping system,the biomass of Sedum alfredii increased by 16.5%,with Cd accumulation in the roots and shoots increasing by 8.8%and 3.6%,respectively.The enrichment coefficients improved by 15.7 and 6.6 units,respectively.After intercropping sweet corn with Sedum alfredii,the Cd content in the top soil significantly decreased.The experiment demonstrated that the phytoremediation model of intercropping Sedum alfredii with sweet corn not only allowed for the simultaneous remediation and production of polluted farmland but also enhanced the extraction efficiency of the hyperaccumulator plant.This approach presented a practical and green remediation technology for moderately heavy metal-contaminated farmland.