铅污染对玉米生长及铅积累的影响

Effects of Soil Lead Pollution on the Growth of Maize and Lead Accumulation

通过玉米盆栽试验,研究4种不同形态Pb在棕壤中的分布规律、不同土壤Pb浓度与玉米生物量的关系和玉米各营养器官Pb积累规律,分析土壤有效态Pb含量与玉米籽粒Pb含量的相关性。研究结果表明:棕壤中各形态Pb的比例为铁锰氧化态>有机结合态>碳酸盐结合态>可交换态;土壤中Pb浓度不同,玉米各器官的Pb积累规律也随之变化;玉米各器官Pb的吸收积累量大小依次为根、叶、茎、籽粒;Pb全量、各形态Pb含量均与玉米各器官的Pb累积量呈显著正相关关系,可交换态Pb与玉米籽实Pb积累的关系较为密切,可作为Pb污染的评价指标。

With the help of the maize pot experiment,the distribution and the accumulation on different vegetative organs of maize in lead content of brown soil and the correlation between the species distribution of lead in soil and its relationship with the lead content of different parts of corn were studied.As a result,the relevant equations concerning the effective state of soil and lead content of maize and grain was established.The results show that the percent of soil forms is in the order of Fe-Mn oxide combined,Organic combined,Carbonate combined,and Exchangeable phase;the accumulation of lead in various organs also will vary as concentration of lead in soil is in different areas;the discipline of absorption of lead accumulation is in the order of roots,leaves,stems,seeds;between full amount of lead of all forms（except for residue） of lead content and the cumulative volume of various organs of maize there is a significantly positive correlation.The exchangeable lead and the accumulation of lead in Maize Seeds have close relationship（correlation coefficient r=0.853）,it can be used for the evaluation of lead pollution index.