Investigation of the effects of winter ryegrass planting on soil heavy metal content and its accumulation and distribution in different organs of late rice in double-rice cropping paddy field with different paddy soil types will play an important role on rice quality safety and environmental security assessment of paddy field. Based on seven years long-term located experiments in paddy fields, we analyzed the effects of winter ryegrass planting on soil heavy metal content and its accumulation and distribution in rice in double-rice cropping paddy field with different paddy soil types including granitic sandy soil (GSS), grey clayey soil (GCS), purple clayey soil (PCS), red yellow clayey soil (RCS), yellow clayey soil (YCS) and alluvial sandy soil (ASS). The results showed that the Cd content in GCS was significantly higher than that in other treatments, while the Pd content in YCS was significantly higher than that in other treatments. RCS had the highest Hg content with 0.029 mg kg-1, and the highest As contents with 29.5 mg kg-1 in YCS. The contents of Cd, Pb and As in late rice showed an order as root > stem and leaves > brown rice. Cd contents in root, stem and leaves, and brown rice planting in RCS were significantly higher than those in other treatments. And the highest Pb and As contents in root of rice planting in YCS was 33.0 and 119.5 mg kg-1, respectively. Meanwhile, the Hg and As contents in rice stem and leaves were significantly higher in ASS than in other soil types. Our results clearly demonstrated that the heavy metal content of brown rice was decreased, and the quality of late rice was ultimately improved under YCS condition.%研究双季稻区不同土壤类型冬季种植黑麦草对土壤重金属含量及其对晚稻不同器官重金属积累与分配的影响,可为水稻质量安全生产和产地安全适宜性评价提供重要参考.本文以7年定位试验为基础,研究了南方双季稻区冬季种植黑麦草对6种不同水稻土耕层土壤重金属Cd、Pd、Hg和As含量的变化及其对晚稻不同器官重金属积累与分配的影响.结果表明,在6种不同土壤类型中,灰泥田土壤Cd含量极显著高于其他土壤类型；黄泥田土壤Pd含量极显著高于其他土壤类型；土壤Hg含量以红黄泥田最高,达0.029 mg kg-1,与其他土壤类型差异达极显著水平；土壤As的含量以黄泥田最高,为29.5 mg kg-1,极显著高于其他土壤类型.6种不同土壤类型晚稻植株Cd、Pb、As含量均为根＞茎叶＞糙米.在晚稻植株根系、茎叶和糙米的Cd含量以红黄泥田最高,均极显著高于其他土壤类型;植株根系Pb、As含量以黄泥田最高,分别为33.0 mg kg-1和119.5 mg kg-1,均极显著高于其他土壤类型；河沙泥水稻植株茎叶的Hg、As含量均极显著高于其他土壤类型.说明黄泥田种植水稻有利于降低稻米中重金属含量,改善稻米品质.
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