Study On Plant Landscape Construction Of Community Garden Under Soil Chromium Pollution

Chromium pollution is a typical representative of heavy metal pollution caused by industrialization and urbanization.It is long-term and latent.Community garden is an important carrier of urban edible landscape.People are increasingly inclined to grow vegetables in cities.However,they paid little attention to the problem of soil chromium pollution in community gardens left over from industrialization and urbanization.This is not conducive to the safe production of edible plants in community gardens and the healthy development of the ecological environment.In the early stage of the project,the soil situation of Jincheng Street Community Garden in Lin ’an District of Hangzhou City was investigated,and it was found that there was a problem of soil chromium pollution,and even some soil chromium content exceeded the safety standard.Therefore,it is necessary to put forward the optimal planting mode of plant landscape for the problem of chromium pollution in community garden soil.After literature review,three plants Trifolium repens,Festuca arundinace and Ageratum conyzoides with certain ornamental value and chromium repair ability were selected in the experiment,and two vegetables Brassica parachinensis and Raphanus sativus with wide audience and no hyperaccumulation of chromium were selected.Pot experiments were set up in two ways : single planting and mixed planting.The growth,physiological characteristics and Cr absorption of plants in Cr contaminated soil under different treatments were analyzed,and the remediation rate of soil chromium pollution was compared.The research is mainly to provide scientific basis for improving the food safety of community garden vegetables and introducing remediation plants to improve soil Cr pollution.Several schemes to solve the problem of chromium pollution in community garden soil while satisfying different functions were obtained.When Trifolium repens was planted alone,Festuca arundinace was planted alone,Raphanus sativus and Festuca arundinace were planted together,the biomass of the restoration plants was larger,and the resistance and enrichment ability to chromium was stronger.These planting methods have obvious effects on repairing soil heavy metal pollution.However,the mixed cropping of Raphanus sativus only improved the repair function of Festuca arundinace.The chromium content in the edible part of Raphanus sativus exceeded the standard value,and Raphanus sativus under this planting method was not edible.When Raphanus sativus is mixed with Trifolium repens,Raphanus sativus meets the food requirements,and Trifolium repens can also grow normally.However,the mixed planting method inhibited the repair ability of Trifolium repens.When Brassica parachinensis was mixed with Ageratum conyzoides,the chromium content of Ageratum conyzoides exceeded the standard and the repair capacity decreased.However,the yield of these two plants increased.The two plants have good ornamental value and can be used for plant landscape construction with single ornamental function.The mixed planting of Trifolium repens and Brassica parachinensis,Raphanus sativus and Ageratum conyzoides is not only ecological and restorative,but also has the function of producing safe crops.The growth of both plants was improved.This planting method improves the yield of vegetables while ensuring the safe production of vegetables.It promotes the absorption of heavy metal chromium in soil by remediation plants.Soil chromium pollution has been well repaired.Mixed planting has good application value in the field of remediation of soil heavy metal pollution.After investigating the excellent community gardens in China,it was found that the planting methods of community garden vegetables were mainly single planting.Managers lack the application of chromium remediation plants.Plant landscape construction lacks attention to soil heavy metal chromium pollution.Combined with the experimental results,some suggestions were put forward for the construction of community garden plant landscape,and the principles and methods of community garden plant landscape construction under soil chromium pollution were summarized.Increasing the application of chromium-remediating plants in the construction of community garden plant landscapes and mixing them with vegetables is a planting method with application potential.The establishment of a plant module for community garden phytoremediation and vegetable food safety under chromium-contaminated soil can provide a scientific basis for future community garden plant landscape construction.