氮肥和钾肥强化龙葵修复镉污染土壤

Intensification of Solanum nigrum L. remedying cadmium contaminated soils by nitrogen and potassium fertilizers

采用室外盆栽实验,研究了施用氮肥[(NH4)2SO4]和钾肥(KCl)对镉超积累植物龙葵(Solanum nigrumL.)的生长和吸收累积Cd的影响.结果表明,(NH4)2SO4虽不能显著提高龙葵地上部Cd含量,但可显著提高龙葵地上部干重,因而显著提高了龙葵地上部Cd的积累量,最大可提高2.8倍;KCl在高浓度处理时可以显著提高龙葵地上部Cd含量,然而它对地上部干重有抑制作用,最终没能提高龙葵地上部Cd的积累量.施用(NH4)2SO4可显著降低土壤pH值,但对土壤有效态Cd含量无显著影响;施用KCl可使土壤pH值显著提高,同时使土壤有效态Cd含量显著增加.(NH4)2SO4的强化龙葵修复效果较好.

Outdoor pot-culture experiments were carried out to study the effects of nitrogen fertilizer [（NH4）2SO4] and potassium fertilizer （KCl） on plant growth and cadmium （Cd） accumulation in Solanum nigrum L., a Cd-hyperaccumulator. Although （NH4）2SO4 could not significantly increase Cd concentration in aboveground tissues of S. nigrum, it could markedly enhance dry biomass of ahoveground parts, thus it significantly increased Cd accumulation in the shoots with a maximal increase of 2.8 folds. In contrast, KCl could significantly increase Cd concentration in aboveground tissues of S. nigrum at its highest addition level, but it might inhibit dry biomass of aboveground parts, so it could not enhance Cd accumulation in the shoots of S. nigrum. And the application of （NH4）2SO4 could significantly reduce pH values in soils, but the concentration of available Cd in soils was not affected markedly. However, the application of KCl could significantly increase pH values in soils, and could markedly enhance the concentration of available Cd in soils. These results indicated that enhancing phytoremediation effect of （NH4）2SO4 was better than that of KCI, and （NH4）2SO4 could be applied to strengthen S. nigrum phytoremediation of Cd-contaminated soils.