Study on the Migration of Heavy Metals Pollution from Soil to Lettuce

Abstract

<abstract> <bold>Abstract. </bold>Protection of soil is important to ensure food safety and quality. Soil heavy metal pollution has been making prominent influences on farmland environment and human body through food chain. It is important to explore the migration of heavy metals from soil to vegetables. This study designed experiments to find the migrations from soil to vegetables. A set of soil samples was collected from Xiaotangshan Precision Agriculture Demo Base in Beijing and mixed with Pb(NO₃)₂<monospace>、</monospace>CrCl₃<monospace>、</monospace>CdCl₂solutions at different amount to make certain levels of Pb(0~2000ppm), Cd (0~100ppm) and Cr (0~3000ppm) content. Samples with single and interacted heavy metals pollution were both prepared in this research. Lettuce was selected as the testing vegetable and seeded in each pot. The lettuce crops were carefully managed in a greenhouse at the Base. After 40 days, lettuces were harvested and labeled. The Pb, Cd and Cr content at root, leaf and stem were tested and analyzed separately. It was found that, single and compound of Pb, Cd and Cr heavy metal does great influence to the growth of lettuce; for the distribution of Pb, Cd, Cr in lettuce plants, there were far greater accumulation in roots than stems and leaves when treated with single and compound pollution of Pb. The distribution trend for Cd accumulation was: root > leaf > stem; for the interaction study between Pb, Cd, and Cr pollution, there was an existence of antagonism between Pb and Cd, Pb and Cr. More experiments are needed to explore more information for the heavy metal migration from soil to vegetables in the future. This research provides a reference for the principle study of heavy metals’ migration and distribution in vegetables.