土壤锌铅镉污染对小白菜硝酸盐含量的影响

通过盆栽试验,研究了土壤锌、铅、镉污染对小白菜体内硝酸盐、亚硝酸盐含量的影响.结果表明：在供试浓度范围内,小白菜的生长效应与重金属施用水平有关,表现为小白菜的生长量随着铅、镉施用水平的增高而降低,差异达极显著水平（T＞t0.01）.锌处理组小白菜生长量则随着浓度的增加而增大.小白菜中硝酸盐含量随重金属施用量的增加而增加,差异达极显著水平（T＞t0.01）.其硝酸盐累积量高低依次为镉污染处理组、铅污染处理组、锌污染处理组;在重金属的单一污染中,小白菜硝酸盐累积量与其受污染程度呈正相关.

EFFECTS OF ZINC LEAD AND CADMIUM CONTAMINATION ON NITRATE CONTENTS IN PAKCHOI

The influences of zinc, lead and cadmium contamination on nitrate and nitrite contents in pakchoi (Brassica parichinensis) were investigated in a pot experiment. In the range of zinc, lead and cadmium levels adopted in this experiment, the growth of pakchoi was correlated negatively with Pb and Cd (T>t_(0.01)) and positively with Zn. Nitrate concentration in the plants increased with the levels of the heavy metals, the effect being significant statistically (T>t_(0.01)). Nitrate accumulation appeared in various treatments in the order of Cd > Pb > Zn. When the soil was treated with a single heavy metal, nitrate accumulation was positively correlated with the degree of heavy metal contamination of the soil.