Key Laboratory of Pollution Ecology and Environment Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China.
College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-resources, Qinling-Bashan Mountains Bioresources Comprehensive Development C.I.C, State Key Laboratory of Biological Resources and Ecological Environment Jointly Built By Qinba Province and Ministry, Shaanxi University of Technology, Hanzhong, 723001, China.
Environ Pollut. 2022 Aug 15;307:119493. doi: 10.1016/j.envpol.2022.119493. Epub 2022 May 18.
Solanum nigrum L. is a Cd hyperaccumulator, but the potential for continuous remediation, or different planting methods have not been fully characterized. The potential for continuous phytoremediation of Cd-contaminated farmland soil (2.08 mg kg Cd) by 2 planting methods (flowering harvest twice a year and maturity harvest once a year) was studied in a 3-year pot experiment. The total Cd accumulation (ug plant) of the 3-year flowering stage treatments was 26.3% higher than that of the maturity stage treatments, which was mainly due to that flowering harvest twice a year caused 65.5% increase of shoot biomass. Similarly, the Cd decreased concentration in soil and Cd removal rate in the flowering stage treatments were 29.2% and 27.9% higher than that in the maturity stage treatments, respectively. After 3 years of phytoremediation, the extractable Cd concentration in soil was reduced by 36.4% in the flowering stage treatments and by 27.6% in the maturity stage treatments, which also led to the same decreasing trend of Cd accumulation of S. nigrum. In conclusion, the study results have demonstrated that the planting mode of two harvests a year at the flowering stage seems to be a viable option to apply for continuous phytoremediation of Cd-contaminated farmland soil.
龙葵是一种镉超积累植物，但连续修复的潜力或不同的种植方法尚未得到充分的描述。通过三年的盆栽实验，研究了两种种植方式（一年开花两次和成熟一次）对受镉污染农田土壤（2.08 mg kg Cd）的连续植物修复潜力。三年开花期处理的总 Cd 积累量（ug 株）比成熟期处理高 26.3%，这主要是由于一年开花两次导致地上生物量增加了 65.5%。同样，开花期处理的土壤中 Cd 浓度降低和 Cd 去除率分别比成熟期处理高 29.2%和 27.9%。经过 3 年的植物修复，开花期处理土壤中可提取 Cd 浓度降低了 36.4%，成熟期处理降低了 27.6%，这也导致龙葵的 Cd 积累量呈相同的下降趋势。总之，研究结果表明，开花期两次收获的种植方式似乎是一种可行的选择，可用于连续修复受镉污染的农田土壤。
