养分调控对超积累植物伴矿景天生长及锌镉吸收性的影响

采用四因素三水平正交设计温室盆栽试验研究了N、P、K三因素不同水平对Zn、Cd超积累植物伴矿景天的生长及地上部Zn、Cd吸收性的影响。结果表明,增施N肥是伴矿景天地上部干重增加的主要因素,高N配施低P(200 mg/kg N,60 mg/kg P,不施K)处理的伴矿景天地上部干重达最大值31.2 g/盆(1.5 kg土/盆),是不施肥处理的3.15倍。增施K肥是提高伴矿景天地上部重金属尤其是Cd浓度和吸收量的主要影响因子,高量K处理比不施K处理地上部Cd浓度增加28.1%;低量施P也可提高伴矿景天的Zn吸取修复效率。综合考虑伴矿景天生物量及其对Zn、Cd的吸取效率,本试验条件下低量N、P肥配施高量K肥为最佳施肥处理(N1P1K2),种植伴矿景天一季对Zn、Cd的吸取量分别为11.2 mg/kg±0.1 mg/kg和0.12 mg/kg±0.02 mg/kg。

Effects of nutrient regulation and control on plant growth and Zn/Cd uptake by hyperaccumulator Sedum plumbizincicola

An orthogonally designed experiment was conducted to investigate the effects of different N, P and K levels on plant growth and the uptake of Zn and Cd by hyperaccumulator Sedum plumbizincicola. The results showed that the addition of nitrogen fertilizer was the main factor in increasing plant biomass, and the highest dry weight (31.2 g/pot) occurred in the treatment of N2P1K0 (200 mg/kg N, 60 mg/kg P, no K), which was 3.15 times of the CK (N0P0K0). K application was the main factor in enhancing concentration and uptake of heavy metals, especially Cd by Sedum plumbizincicola. Cd concentration in shoot of the treatments of 160 mg/kg K was 28.1% higher than the treatments of no K addition, and the phytoextraction efficiency could be improved when low amount of P (60 mg/kg P) was applied. By comprehensively considering the biomass of Sedum plumbizincicola and the uptake amount of Zn and Cd, it was proposed that the best treatment was low N and P but high K (N1P1K2), and Zn and Cd phytoextraction rates in one season of Sedum plumbizincicola were 11.2 mg/kg and 0.12 mg/kg, respectively.