Screening Of Amendments For Soil Safety Production In Cd And Ni Contaminated Facilities And Its Function Characteristics

Greenhouse vegetables play an important role in agricultural industry in Jilin Province,however,with the intensification of greenhouse vegetable production,the excessive use of agricultural inputs containing heavy metals has led to a lot of environmental problems,On the other hand,there are few studies on heavy metal pollution in greenhouse vegetable soil at home and abroad,and even fewer studies on the remediation and safety production of Cd and Ni contaminated soil.Therefore,in this paper,the Cd and Ni contaminated vegetable fields near a mining area in Jilin Province were taken as the research objects,and the passivation and remediation of Cd and Ni in soil by five amendments(liquid mineral fertilizer,calcium magnesium phosphate fertilizer,bamboo charcoal biological organic fertilizer,biological bacteria fertilizer and foliage fertilizer)and their effects on the absorption and enrichment of Cd and Ni by leafy vegetables,rhizomes and solanaceous vegetables were explored,so as to screen out the vegetables with high remediation efficiency and to meet the facilities of vegetable safety production of amendments.The main results were as follows:(1)Liquid mineral fertilizer,calcium magnesium phosphate fertilizer,bamboo charcoal biological organic fertilizer,biological bacteria fertilizer and foliage fertilizer can improve the pH and organic matter content of rhizosphere soil in different degrees,and the influence degree is related to the conditioners and vegetable types.The pH of rhizosphere soil of various vegetables increased by 0.10-1.21 units,and the liquid mineral fertilizer increased the pH of rhizosphere soil of cucumber by 23.6% compared with the control.The organic matter content of all kinds of vegetables was increased by 1.07 to 6.57 units,among which calcium magnesium phosphate fertilizer increased the organic matter content of eggplant rhizosphere soil by 16.2%compared with the control.(2)The effects of conditioners on the absorption and enrichment of Cd and Ni in vegetables were related to vegetable species and heavy metals.Liquid mineral fertilizer could reduce the pakchoi cabbage and spinach state Cd and Ni soil effective coefficient of 13.5% to 15.7% and18.2%-28.6% respectively,the edible vegetables department of Cd and Ni enrichment coefficient was reduced by 11.8%-13.8% and 11.7%-33.3% respectively,to reduce the effect of pakchoi cabbage is stronger than spinach,but cannot make turnip,cucumber and eggplant on Cd and Ni absorption decrease and cannot meet the food safety standards;Calcium-magnesia phosphate fertilizer can reduce the radish,cucumber and eggplant state Cd and Ni soil effective coefficient of 11.3% to 22.8% and 15.3% 51.6% respectively,the edible vegetables department of Cd and Ni enrichment coefficient was reduced by 9.4%-17.6% and 17.3% 38.1% respectively,to reduce the effect of eggplant,cucumber effect,but can’t make the absorption of pakchoi cabbage and spinach to the Cd and Ni reduce pakchoi cabbage,spinach and turnip and cannot achieve the food safety standards;Bamboo charcoal biological organic fertilizer can reduce the pakchoi cabbage and eggplant soil Cd and Ni effective coefficient of 6.6%-22.2% and 3.2%35.8% respectively,the edible vegetables department of Cd and Ni enrichment coefficient was reduced by 10.6%-16.9% and 12.8%-21.4% respectively,the eggplant to reduce the effect is better than pakchoi cabbage,but you can’t make the spinach,carrots and cucumbers on Cd and Ni absorption decrease and cannot meet the food safety standards;The effective coefficients of Cd and Ni in cucumber and eggplant soil decreased by 5.6%-8.5% and 4.3%-30.5%,respectively,and the enrichment coefficients of Cd and Ni in edible parts of vegetables decreased by 4.9%-12.4% and 6.1%-14.3%,respectively.The effect of reducing Cd and Ni in eggplant was stronger than that in cucumber,but it could not reduce the absorption of Cd and Ni in cabbage,spinach and radish,and could not meet the food safety standards.(3)All selected vegetables on Cd enrichment ability and the content of soil effective state Cd has very significant positive correlation,and the soil pH is significant or extremely significant negative correlation,cucumber and eggplant on Cd enrichment ability also were very significant negative relationship with the organic matter content,and pakchoi cabbage,spinach and turnip on Cd accumulation ability and no correlation between soil organic matter content.Were used by the same token,the vegetables of Ni enrichment capability and soil effective state of Ni content also has very significant positive correlation,and the enrichment of pakchoi cabbage and eggplant for Ni ability with pH and organic matter content were significantly or extremely significantly negative correlation,but the spinach,carrots and cucumbers edible part of Ni concentration ability and no correlation between soil pH and organic matter content.In conclusion,in order to realize the safe production of vegetable soil polluted by Ni and Cd,the recommended use of soil conditioner is as follows: for Cd contaminated soil,liquid mineral fertilizer and bamboo charcoal biological organic fertilizer can be used for growing pakchoi cabbage and spinach;liquid mineral fertilizer,calcium magnesium phosphate fertilizer and biological bacteria fertilizer can be used in the cucumber planting;calcium magnesium phosphate fertilizer,bamboo charcoal biological organic fertilizer and biological bacterial fertilizer can be used for eggplant planting.For Cd and Ni contaminated soil,liquid mineral fertilizer and bamboo charcoal biological organic fertilizer can be used to plant pakchoi cabbage,liquid mineral fertilizer can be used for the spinach planting;calcium magnesium phosphate fertilizer and biological bacteria fertilizer can be used for the cucumber planting,and calcium magnesium phosphate fertilizer,bamboo charcoal biological organic fertilizer and biological bacteria fertilizer can be used for the eggplant planting.Although the conditioner had a certain passivation and remediation effect on radish soil and reduced the absorption of Cd and Ni,the content of Cd and Ni did not meet the requirements of national food safety standard(GB2762-2017)and hygienic standard of nickel limit in food(1994).For the sake of food safety,it was suggested that other amendments should be used or the radish should not be planted in the experimental site.