蚓粪-贝壳粉配施对镉轻度污染菜地生菜和青蒜生产的影响

Effects of vermicompost and shellfish powder combined application on the production of lettuce and green garlic in lightly cadmium contaminated vegetable fields

在杭州富阳区开展田间小区试验,比较了3种调理剂(100%(质量分数,下同)蚓粪(R3)、95%蚓粪和5%贝壳粉(R4)、95%蚓粪和5%改性贝壳粉(R5))施用下对镉(Cd)轻度污染菜地的土壤pH、铅(Pb)/Cd生物有效性和种植蔬菜中重金属富集系数的影响。结果表明:(1)R5处理下青蒜中Cd(0.0292 mg/kg)比空白对照(CK)处理中(0.0640 mg/kg)降低了54.4%,符合《食品安全国家标准食品中污染物限量》(GB 2762—2017)(0.05 mg/kg)。(2)生菜和青蒜中Cd的平均富集系数最高(分别为0.08582、0.06553)。调理剂能降低Cd从土壤转移到蔬菜中的风险。(3)R5处理能有效降低收获生菜后土壤有效态Cd,且与CK、R3处理差异显著(P<0.05);降低收获生菜和青蒜后土壤Cd生物有效性系数。

A field plot experiment was conducted in Fuyang district,Hangzhou.The effects of three conditioners(100%(mass fraction,the same below)vermicompost(R3),95% vermicompost and 5%shell powder(R4),95%vermicompost and 5%modified shell powder(R5))on soil pH,lead(Pb)/cadmium(Cd)bioavailability and heavy metal enrichment coefficient in vegetables in lightly Cd contaminated vegetable fields were compared.The results showed that:(1)with R5 treatment,Cd(0.0292 mg/kg)in green garlic decreased by 54.4% compared to blank control(CK)treatment(0.0640 mg/kg),which meeted the“National standard for food safety-Limit of contaminants in foods”(GB 2762-2017)(0.05 mg/kg).(2)The average enrichment coefficients of Cd were the highest in both lettuce and green garlic(0.08582 and 0.06553 respectively).Conditioners could reduce the risk of Cd transfer from soil to vegetables.(3)The available Cd in soil after havesting lettuce could be decreased effectively with R5 treatment,which showed significant difference compared with CK and R3 treatments.The bioavailability coefficients of Cd in the soils after harvesting lettuce and green garlic were also decreased with R5 treatment.