高效栽培雷竹林土壤重金属含量的分析研究

Changes in Heavy Metal Elements of Soil in Ecosystem of Phyllostachys praecox under Intensive Management

雷竹(Phyllostachyspraecox)是最近十几年发展起来的优良笋用竹种,近年来以重施肥和冬季地表覆盖增温为核心的高效栽培技术在生产上得到了大面积推广。为了解高效栽培雷竹林土壤重金属含量现状,采集了浙江省雷竹主产区40个样点土壤样品,利用ICP法分析了土壤重金属含量。结果表明,雷竹林土壤重金属镉(Cd)、铬(Cr)、铜(Cu)、铅(Pb)和锌(Zn)全量含量分别为0.23±0.11,68.23±25.61,23.26±6.61,12.47±2.86,108.50±54.92mg/kg,所有样点5种重金属全量均未出现超标现象。Cd、Cr、Cu、Pb和Zn有效态含量分别为0.028±0.025,0.150±0.102,3.482±1.304,1.636±1.022,10.814±9.767mg/kg,5种重金属有效态含量变异均明显大于全量。重金属Cd、Cu、Pb和Zn有效态含量占全量百分比较高。从不同栽培历史雷竹土壤重金属含量变化来看,Cu、Pb、Zn3种元素随着栽培历史延长,土壤中全量含量显著上升,其中Cu上升量最大,栽培历史从2～3年延长到8～10年,Cu含量增加了1.39倍。重金属Cd、Cu、Zn全量与有效态含量间具有显著或极显著相关性。

Phyllostachys praecox being able to produce delicious bamboo shoots have been planted widely in Zhejiang province. The practice of surplus fertilizing and winter mulching has been a common cropping technique in the near decade to get earlier bamboo shoots and then a high economic profit, it caught people's attention about heavy metal pollution in soil. The objective of this paper is to investigate the general situation of soil heavy metal elements in the system. Total 40 soil samples were collected and heavy metal elements were analyzed by ICP. The amount of total heavy metal elements were not exceed the standard, the concentration of Cd, Cr, Cu, Pb and Zn were respective 0.23±0.11,68.23±25.61,23.26±6.61,12.47±2.86 and 108.50±54.92 mg/kg. Soil available heavy metal elements were more variable in amount than total form. The ratio of available to total in concentration of heavy metal elements were relative higher compared with other's result from vegetable soil. The total amount of Cu, Pb and Zn increased with the mulching year ,especial Cu, there was an increase of 1.39 folds from 2~3-year to 8~10-year mulching. The close relationships between available and total concentration of Cd, Cu and Zn elements were observed.