油菜-水稻轮作对作物吸收累积镉的影响  

Bioavailability of Cadmium in the Rotation System of Oilseed Rape and Rice Grown in Cd-contaminated Soil

作　　者：于玲玲[1] 朱俊艳[1] 黄青青[1] 苏德纯[1] 江荣风[1] 李花粉[1] 

机构地区：[1]中国农业大学资源与环境学院,北京100193

出　　处：《环境科学与技术》2014年第1期1-6,12,共7页Environmental Science & Technology

基　　金：公益性行业(农业)科研专项(200903015);国家自然科学基金项目(40971261);国家"863"重点项目(2007AA061001)

摘　　要：通过田间试验,利用不同吸镉特性的油菜与水稻轮作,研究镉污染农田土壤上不同轮作体系中植物对重金属的吸收累积规律,探索重金属污染土壤上农产品安全生产模式。研究结果表明:在镉污染农田土壤上,2个不同吸镉特性的油菜品种籽粒的产量没有显著性差异,高积累镉油菜品种朱苍花籽的籽粒中镉含量为0.29 mg/kg,超出食品污染物限量标准值的45%;而低积累镉油菜品种川油Ⅱ-93籽粒中镉含量为0.14 mg/kg,符合标准限值。2个油菜品种根系对根际土壤中的镉有不同程度的活化作用,川油Ⅱ-93的根际土有效镉含量由0.41 mg/kg上升到0.72 mg/kg,增长75.6%;朱苍花籽根际土中有效镉含量由0.45 mg/kg上升到0.55 mg/kg,增长22.2%。油菜收获后显著影响了下茬水稻糙米中镉的含量,油菜朱苍花籽成熟收获后种植水稻的轮作体系中,糙米中镉含量为0.22 mg/kg,超过标准限值10%,而其他轮作体系中糙米镉含量符合标准限值。通过品种筛选可以实现镉污染农田土壤的作物安全生产。A field experiment was performed to study the uptake and accumulation of cadmium （Cd） in different oilseed rape varieties and rice rotation systems on a Cd-contaminated farmland, and also to explore the agricultural production patterns with food safety. Results showed that Cd concentration in the seed of the high Cd accumulating oilseed rape variety Zhucang Huazi reached 0.29 mg/kg, which was 45% higher than the permissible limit, however it was only 0.14 mg/kg for the low Cd accumulating oilseed rape variety ChuanyouⅡ-93, which was below the permissible limit. The yield of two varieties of oilseed rape showed no significant difference. The concentration of DTPA-extractable Cd increased from 0.41 mg/kg to 0.72 mg/kg lay 75.6% and from 0.45 mg/kg to 0.55 mg/kg by 22.2% in the rhizosphere of Chuanyou Ⅱ -93 and Zhucang Huazi respectively, which showed the mobilization of the root system on Cd in the rhizosphere of oilseed rape. Furthermore, previous planting of oilseed rape also significantly influenced the Cd concentration in brown rice planted after oilseed rape, and Cd concentration in the brown rice was 0.2 mg/kg which exceeded the permissible limit by 10% in the rotation system of Zhucang Huazi mature harvest-rice, while it was lower than the permissible limit in other rotation systems. Agricultural production with food safety can be implemented in the Cd--contaminated agricultural farmland through the selection of varieties.

关 键 词：镉污染土壤 轮作 生物有效性 油菜 水稻 

分 类 号：X173[环境科学与工程—环境科学]