不同耕作方式下川芎对土壤中铅、镉含量的富集特征

以彭州川芎种植区的菜园土、稻田翻耕土、稻田免耕土和旱地(未种过川芎和蔬菜)四种土壤为研究对象,探讨了不同耕作方式下川芎对土壤中Cd、Pb的富集特征。结果表明:在四种耕作方式下,菜园土中Cd、Pb含量显著高于其他三种土壤,分别为1.10mg·kg-1和29.78mg·kg-1;土壤Cd综合污染指数和Hacanson系数分别为3.76和133.07,处于重污染和强生态危害状态。稻田翻耕土、稻田免耕土和旱地三种类型土壤在Cd含量上差异显著,依次为稻田免耕土(0.86mg·kg-1)稻田翻耕土(0.59mg·kg-1)旱地(0.37mg·kg--1),在Pb含量上三者差异不显著。川芎植株对Cd的富集在菜园土中显著高于其他土壤,表现为菜园土稻田免耕土旱地稻田翻耕土;川芎植株对Pb的富集以在稻田免耕土中最大,依次为稻田免耕土旱地稻田翻耕土菜园土。在四种土壤中,川芎叶片对Cd、Pb的富集能力均大于根茎,其中川芎叶片对Cd的富集能力是根茎的1.37倍,对Pb的富集能力是根茎的1.42倍,二者对Cd的富集能力在菜园土中差异最大(叶/根为1.56),对Pb的富集能力在稻田免耕土中差异最大(叶/根为1.98)。川芎对Cd、Pb的富集主要受轮作作物种类和耕作措施的影响。

Enrichment characteristics of lead and cadmium in Ligusticum chuanxiong under different tillage methods

Four types of soil with different previous crops as leaf vegetable,rice （no-tillage and conventional tillage）and other crops were studied to explore characteristics of cadmium （Cd）and lead （Pb）accumulation in Ligusticum chuanxiong.Results show that after different tillage methods,the concentrations of Cd and Pb in vegetable soil were much higher than the other three ones with 1. 10 mg＆#183;kg-1 of Cd and 29. 78 mg＆#183;kg-1 of Pb.The indexes of Nemerow Pollution and Hacanson of Cd in the soil were 3.76 and 133.07 which indicated that the current situation of the soil was in danger of heavy metal pollution by Cd. Contents of Cd were significantly different among the remain types and showing an order of no-tillage soil（0. 86 mg＆#183;kg-1 ）〉conventional tillage soil（0.59 mg.kg-1 ）〉dry land （0. 37 mg＆#183;kg-1 ）while contents of Pb were not .The enrichment for Cd in vegetable soil was the highest one compared with the others and show the order of vegetable soil 〉 conventional tillage soil 〉dry land 〉no-tillage soil from the entire plant.Otherwise,the plant accumulated much more Pb in no-tillage soil than oth-ers and show a different order as no-tillage soil〉 dry land 〉 conventional tillage soil〉 vegetable soil.In the four types of soil,the biological concentration factor in leaves of Ligusticum chuanxiong was 1.37 times higher than the rhizomes for Cd and was 1.42 times for Pb.The maximum as 1.56 of the former was in the vegetable soil and the one （1.98）of the latter was in no-tillage soil.Contents of the elements in soil were effected by previous crop species and farming methods mostly.