Effects Of Combined Application Of Different Amendments On The Content Of Available Lead In The Soil And The Growth Of Pakchoi

Various environmental problems caused by the development of industry and agriculture in our country have become increasingly prominent,especially the problem of heavy metal pollution in farmland soil.The restoration and improvement of heavy metal contaminated farmland soil has attracted much attention.Therefore,one or more restoration effects are stable,efficient and inexpensive.The easily available soil amendments are particularly important.In recent years,biochar has been widely used as a new type of soil remediation and improvement material.However,there are few studies on the repair effect and mechanism of biochar and different modifiers,and some repair materials are mostly aimed at the removal of heavy metal ions in the solution.This article aims to reduce the effective Pb content in the lead-contaminated soil and reduce the Pb content of the ground part of Chinese cabbage.Biochar,shell powder and wood vinegar are used as modifiers.In-situ chemical passivation technology is used to select the daily diet of Chinese residents.Common Chinese cabbage was used as the test material for soil pot experiment.The p H value of the soil,the content of available Pb in the soil,the content of Pb in the shoots of Chinese cabbage,the fresh weight and plant height of Chinese cabbage,the chlorophyll content of Chinese cabbage leaves,antioxidant enzyme activity and the content of malondialdehyde and other indicators are used for preliminary exploration.Get the following conclusions:(1)Adding amendments can increase soil p H and reduce soil available Pb content.The combined application of biochar and shell powder,and the combined application of biochar and wood vinegar are better than single application.Compared with the control group,combined application of biochar and shell powder reduced the soil available Pb content by 29.07% ? 43.27%,combined application of biochar and wood vinegar reduces the soil available Pb content by 2.98% ?30.41%.As a result,better proportions were 5% biochar and 5% shell powder,5% biochar and 0.2% wood vinegar.(2)Adding modifiers can reduce the Pb content in the shoots of Pakchoi,increase the height and fresh weight of Pakchoi.The combined application of biochar and shell powder,and the combined application of biochar and wood vinegar are better than single application.Compared with the control group,combined application of biochar and shell powder reduced Pb content in the shoots of Pakchoi by 29.07% ? 43.27%,and increased plant height and fresh weight by 25.57% ? 43.11% and 27.37% ? 58.44%,combined application of biochar and wood vinegar reduced the Pb content in the shoots of Pakchoi by 2.98% ? 30.41%,and increased the plant height and fresh weight by 17.79% ? 39.30% and 31.59% ? 76.80%.As a result,better proportions were 5% biochar and 5% shell powder,5% biochar and 0.2% wood vinegar.(3)Adding modifiers can increase the chlorophyll content of Pakchoi leaves,reduce the content of malondialdehyde and the activity of antioxidant enzymes.The combined application of biochar and shell powder,and the combined application of biochar and wood vinegar are better than single application.Compared with the control group,combined application of biochar and shell powder increased the chlorophyll content of Pakchoi leaves by 29.07% ? 43.27%,and the content of malondialdehyde decreased by 30.37% ? 49.63%,The combined application of biochar and wood vinegar can increase the chlorophyll content of Pakchoi leaves by 2.98% ? 30.41% and reduce the content of malondialdehyde by 29.26% ? 54.11%.As a result,better proportions were 5% biochar and 5% shell powder,5% biochar and 0.2% wood vinegar.In summary,the combined application of biochar with shell powder and wood vinegar can reduce the content of soil available Pb and the accumulation of Pb by cabbage.In this paper,the optimal ratios are combination of 5% biochar and 5% shell powder?combination of 5% biochar and 0.2% wood vinegar.