田间条件下养分调控八宝景天Cd修复效率

在田间条件下,采用四因素三水平正交试验研究了N、 P、 K三因素不同水平对Cd富集植物八宝景天的生长和Cd吸收性的影响.结果表明,八宝景天生物量随施N水平的提高而增加,高N水平下(337.5 kg·hm~(-2))八宝景天地上部生物量最大,为不施肥处理的0.86～2.00倍,但对其地上部Cd含量无显著影响.K肥对八宝景天Cd吸收具有一定的促进作用,高K水平下其地上部Cd含量最高达22.05 mg·kg~(-1),较不施肥处理提高29.3%.综合分析,NPK肥料配施条件下,N肥和K肥分别是八宝景天生长和Cd吸收效率的主要影响因素,且对八宝景天Cd积累表现出明显的交互作用.肥料对八宝景天Cd提取量影响顺序为NKP,其中对八宝景天Cd修复效率的促进作用主要通过提高八宝景天生物量,高量N肥配施适量P、 K肥是提高八宝景天Cd修复效率的最佳施肥措施,其地上部Cd积累量较不施肥处理提高了0.9～2.2倍,合理增施N肥是提高八宝景天Cd修复效率的主要影响因子.

Effect of Nutrient Regulation and Control on Cd Accumulation Efficiency of Hylotelephium spectabile Under Field Conditions

A field experiment with an orthogonally designed experiment L9(3⁴) was designed to investigate the effect of different N, P, and K levels on plant growth and Cd uptake by Hylotelephium spectabile. The results showed that the biomass of H. spectabile significantly increased with the N application rate. The highest dry weight in the shoot occurred in the treatments with a high level of N (337.5 kg ·hm^-2), which was 0.86-2.00 times higher than the value with no fertilizer treatment. The addition of K contributed to promoting the Cd absorption of H. spectabile, while no effect was observed when N and P were added. Consequently, NPK fertilizers contribute to increasing the Cd uptake of H. spectabile, and the N and K fertilizer play important role in plant growth and Cd absorption respectively. Moreover, the effect of fertilizers on Cd uptake of H. spectabile was in the order of N > K > P, which indicated that N fertilizer was the main factor for promoting the Cd phytoextraction efficiency of H. spectabile by increasing the biomass. Therefore, the application of high levels of N combined with moderate levels of P and K will be an effective approach to improve the Cd phytoremediation efficiency of H. spectabile by promoting its growth, and the Cd uptake can be increased by a factor of 0.9-2.2 compared to no fertilizer treatment condition.