Study On Remediation Of Cd And Pb Contaminated Soil By Intercropping Maize With Sedumplumbizincicola/vetiveria Zizanioides

The soil is the necessary material for human survival,and it is one of the most important natural resources of mankind.The heav y metal in farmland has become one of the important factors restric ting the grain production and economic development in China.Ther efore,it is very important to carry out the research on the remediat ion of heavy metal compound soil.In this paper,we used the indo or root box experiment to select the soil heavy metals Cd and Pb as the research object,and studied the repairing characteristics of w axy maize and common maize,respectively intercropping with Sedu m plumbizincicola/Vetiveria zizanioides.Effects of organic manure a ddition on soil heavy metals.The results show:Intercropping can promote the biomass of various parts of wax y corn and common corn,and promote the effect:grain>shoot>un derground part.In the intercropping model,the biomass of the roots of the Vetiveria zizanioides and the stem of Sedum plumbizincicola increased significantly,while the aboveground biomass of the Vetiv eria zizanioides and the leaves of the Sedum plumbizincicola decrea sed.The concentration of Cd in different parts of corn was root>1 eaf>spike>bract>stem>core>beard>grain,Pb concentration was root>leaf>stem>bract>spike>beard>core,intercropping do not change the Cd and Pb concentration trends,but inhibited the absor ption of Cd with the Sedum plumbizincicola,and promoted the abs orption of Pb by Vetiveria zizanioides.Maize had good absorption of Cd and Pb(300-400 ?g/plant for waxy maize and 450-700 ?g/plant for common maize),and the main parts for Cd and Pb ab sorption were roots,stems and leaves.In addition,intercropping wa s effective Promoted the overall absorption of Cd and Pb in maize,but the effect of reducing heavy metal Cd in maize grain was re markable.Intercropping had no obvious effect on the morphology o f soil Cd,Pb and soil microbes in soil rhizosphere soil.Overall,in tercropping corn and Vetiveria zizanioides works better.Application of organic fertilizer on the growth of Vetiveria zizanioides and Sedum plumbizincicola(single)has a good promotion effect.Application of organic manure reduced the uptake of Cd and Pb by single crops(corn and Vetiveria zizanioides),and promoted the absorption of heavy metals by the corresponding intercropping.On the other hand,organic manure had no significant effect on single Sedum plumbizincicola,but reduced the amount of Cd and Pb absorbed during the intercropping process.The contents of Cd and Pb in the rhizosphere soil of monocropped organic manure were decreased,especially in the rhizosphere soil of Sedum plumbizincicola.The application of organic manures significantly enhanced the activity of single-cropping and intercropping microorganisms and the response time to carbon sources,and the single-cropping improvement effect was better than that of intercropping.Organic fertilizers can significantly increase soil microbial activity,diversity and carbon utilization efficiency.