摘要
针对硅酸盐或腐植酸在重金属污染土壤上的最佳施用量研究较少的问题,为保障蔬菜的品质安全,本文通过土壤盆栽试验,研究了硅酸盐、腐植酸对Cr和Pb单一污染及Cr-Pb复合污染土壤中小白菜(Brassica Chinensis)的生物量、生理指标的影响。结果表明,施用硅酸盐对Cr-Pb污染的的抑制效果较好。其中1.0g·kg-1质量分数的硅酸盐施用效果最佳,在小白菜未受污染时能促进生长;在受Cr-Pb污染后虽然促生长作用不明显,但施用后能有效减轻Cr-Pb污染对小白菜体内超氧化物歧化酶(SOD)活性的抑制,缓解小白菜根部细胞受到的过氧化损伤。同时发现,施硅量过高(2.0g·kg-1)或当土壤中存在Pb污染时施用1.5g·kg-1以上质量分数的硅酸盐则对生长产生抑制。腐植酸也能在一定程度上提高超氧化物歧化酶(SOD)、过氧化物酶(POD)的活性,但是对小白菜受到过氧化胁迫的缓解效果不如硅酸盐明显,对小白菜生长的促进作用不显著。
Pb pollution in soil was very severe in Guangdong. Cr concentration was less than the background value in most soil, but it exceeded standard in suburb cultivated land. The situation of soil heavy metal pollution was threatenning the quality and safety of vegetable production in Guangdong. Aiming at optimization of manuring level of silicates and humic acid, pot experiments were carried out to study the effects of silicates and humie acid on growth and physiology of Brassica Chinensis which were growing up in Cr, Pb and Cr-Pb contaminated soil. The results indicated that, the inhibitory effect of silicates on toxicity of Cr-Pb pollution was better than humic acid＇ s, and 1.0 g·kg^-1 silicates has the best effect. That mass fraction of silicats could improve the growth of unpolluted Brassica Chinensis, and promote the SOD activity of Brassica Chinensis polluted by Cr-Pb, alleviate the damage of membrane lipid peroxidation of root＇ s plasma membrane. While high level silicates （2.0 g·kg-1 ）or interaction between Pb and high level silicates （ above 1.5 g·kg-1 ）would inhibit the growth. Humic acid could also promote SOD and POD activity in a certain degree, but its detoxification and promoting effect on growth were not significant.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2008年第6期2338-2344,共7页
Journal of Agro-Environment Science
基金
广东省农业领域攻关项目(2006B20601007,2007B060401030)
关键词
小白菜
硅酸盐
腐植酸
Cr-Pb复合污染
Brazsica Chinensis
silicates
humic acid
Cr-Pb compounded pollution
