不同铜浓度下玉米间作豌豆对土壤铜的吸收效应研究

Effect of Maize-Pea Intercropping on Crop Copper Accumulation under Different Copper Concentrations

为探讨玉米间作模式对铜污染土壤的修复效果,通过盆栽实验研究了玉米||豌豆和玉米单作种植模式对不同铜浓度(0、100、200、400、600 mg·kg-1)处理下玉米地上部与地下部的铜含量与铜累积量、铜富集与转运系数、土壤全铜和有效铜含量的影响。结果表明:在间作和单作模式中玉米地上部铜含量最高的处理均为铜浓度200 mg·kg-1,而玉米地上部铜含量最低的处理在单作模式下是铜浓度600 mg·kg-1,间作模式下是100 mg·kg-1。相同铜浓度下,间作模式的玉米地上部铜含量均显著低于单作模式,其中降幅最大的为铜浓度100 mg·kg-1,降幅为49.4%;而间作模式的玉米地下部铜含量均显著高于单作模式,其中增幅最大的为铜浓度100 mg·kg-1,增幅为105.4%。间作模式的玉米地上部富集系数均显著低于单作,而地下部富集系数均显著高于单作。从种植系统整体来看,除铜浓度400 mg·kg-1处理外,其余各处理中间作玉米铜累积量均低于单作玉米,但差异不显著。除铜浓度0 mg·kg-1和400mg·kg-1处理外,其余各铜浓度处理下,间作玉米富集系数均低于单作玉米,且所有间作模式的玉米转运系数均显著低于单作玉米。相同铜浓度下,不同玉米种植模式对土壤全铜和有效铜没有产生显著影响。总的来说,玉米间作豌豆能增加玉米地下部铜含量,降低玉米地上部铜含量,在提高间作系统总的铜累积量的同时,降低了铜元素从玉米地下部向地上部的转运。

Crop intercropping increases biodiversity and stability of agricultural production systems,and it may also enhance plant accumulation of heavy metals from soils.Here a pot experiment was conducted to study the effects of different concentrations of copper(0,100,200,400,600 mg·kg-1)and two cropping patterns(maize monoculture and maize-pea intercropping)on copper content,accumulation,enrichment coefficient,and transfer coefficient of crops and on soil total copper and available copper content.Results showed that the highest copper content of maize aboveground part in both monoculture and intercropping systems was observed at 200 mg·kg-1,while the lowest copper content in maize shoots was found at 600 mg·kg-1in monoculture,but 100 mg·kg-1in intercropping.Under the same concentration of copper added,the content of copper in maize shoot was significantly lower in intercropping than in monoculture systems,but the maize root copper was significantly higher in intercropping than in monoculture systems.Compared with the monoculture,inctercropping practice caused the biggest decrease(49.4%)in maize shoot Cu but the greatest increase(105.4%)in maize root Cu at 100 mg·kg-1.Copper enrichment coefficients of maize shoot in intercropping system were significantly lower than those in monoculture system,but the results were just opposite for the maize root.At all Cu rates but 400 mg·kg-1,copper accumulation in maize tended to be lower in intercropping than in monoculture systems.The copper enrichment coefficients and transfer coefficients in maize in intercropping systems were lower than those in monoculture systems,under different copper stresses,with except of 0 mg·kg-1and 400 mg·kg-1treatments.Different cropping systems exhibited no significant effects on total and available copper in soil under different copper concentrations.In conclusion,the maize--pea intercropping could increase the copper content in maize root,reduce copper concentrations in maize shoot,and enhance total copper accumulation by crops,but decreases the copper transport from maize root to shoot in comparison with monoculture.