Vegetable Varieties Screenint With Low Cd-Pb Accumulation And The Associated Soil Remediation Techniques

Along with the rapid economic development and the rising of people's living standards in China, the public are paying ever greater attention to food safety and the human health. The rapid socio-economic development bring out, meanwhile, severe environment peoblems. For example, there occurred many heavy metal pollution events in recent years in defferent areas in China, which brought relevant food safety problems. Therefore, in the heavy metal pollution area, the work on vegetable varieties selection with low metal accumulation and the associated soil remediation technology is valuable and important for sustainable agricultural production.We selected an abandoned lead-zinc mine surrounding farmland in Shangyu county, Zhejiang province, as the study area. The total and available Cd, Pb concentrations in soil and vegetables were determined. And the vegetable varieties screening with low heavy metal accumulation was studied. After operating the work on health risk assessment of heavy metal pollution, we explored the soil remediation technology of heavy metal in this pollution area. The main conclusions are as the follows:(1) The results of vegetable varieties screening with low metal accumulation showed, for lead, the varieties are HuoQing 91-5c, Hong Kong Sijiqing vegetables, Gao Huaqing cabbage, and YouDongEr. Low cadmium accumulation varieties are HuoQing 91-5c, Huaying, Zaoshu 6, and YouDongEr. The low accumulation of heavy metals for both Cd and Pb vegetable varieties are HuoQing 91-5 c and YouDongEr.(2) Nemerow comprehensive index and the fuzzy mathematical evaluation methods were imployed in this study for soil pollution assessment in the study area. Nemerow comprehensive index evaluation method and the calculation results showed that the study area is lightly polluted and Pb pollution is heavy. Synthesis of two kinds of heavy metal elements Cd and Pb compound pollution evaluation showed that the study area is heavily polluted. The risks for adults are higher than children, risks for woman are higher than man.(3) Rice straw biochars, swine manure and the calcium hydrogen phosphate were selected as three additions for local soil heavy metal remediation. According to the results of field experiments, when the phosphate fertilizer usage is 0.2 kg/m2, the composting usage is 2kg/m2, HuoQing 91-5c vegetable accumulated lowest heavy metal. When phosphate fertilizer usage is 0.2 kg/m2, rice straw biochars usage is 1 kg/m2. Heidatou vegetable works best. Variance test results showed that when the biochars content 1 kg/m, phosphate fertilizer content is 0.2 kg/m, the amount of added compost for 2 kg/m2, both two above vegetables absorbed lowest heavy metal.Two heavy metals of Cd and Pb in soil showed the synergy effect. In July and September, the availability of heavy metals content is lower than that in December.