不同种植模式对稻田土壤重金属含量及晚稻稻米品质的影响

为了寻求消减土壤重金属的种植模式，确保食物安全，以6年定位试验，研究了5种不同种植模式对稻田土壤重金属Cd、Pb、Hg、As含量、晚稻植株重金属的积累与分配、稻米品质及产量的影响。结果表明，与冬闲-双季稻(CK)相比，黑麦草-双季稻(T1)、紫云英-双季稻(T2)、油菜-双季稻(T3)和马铃薯-双季稻(T4) 4种冬种模式对土壤重金属含量表现出明显差异，其中T1土壤As，T2土壤Cd、Hg、As，T3土壤Cd、Hg，T4土壤Pb、Hg含量均显著低于CK，但T1土壤Hg，T3土壤As，T4土壤Cd、As含量显著高于CK。不同种植模式晚稻植株重金属含量均为根>茎叶>糙米，冬种模式根重金属含量均低于CK，茎叶Cd含量均高于CK，茎叶Pb、Hg、As含量表现不稳定，糙米Cd、Pb含量除T4 Cd外,其余均显著低于CK。冬种模式均增加了稻米出糙率、整精米率、胶稠度和直链淀粉含量，降低了垩白米率和垩白大小。冬种模式增加了晚稻产量，其中T4比CK显著增产17.52%。上述结果说明，冬种模式有促进消减土壤部分重金属污染趋势，但其作用有限，并能一定程度降低糙米Cd、Pb含量，改善稻米品质和提高水稻产量。

Impacts of Winter Planting Patterns on Soil Heavy Metal Content and Grain Quality in Late Rice in Double Cropping Rice Area

On the basis of six-year fixed-location experiments in paddy fields, analysis was made on the impacts of different win-ter cropping patterns on soil heavy metal content, heavy metal content in different parts of late rice and late rice grain quality in double rice cropping area. The winter cropping patterns were ryegrass and double cropping rice (T1), Chinese milk vetch and double cropping rice (T2), rape and double cropping rice (T3), potato and double cropping rice (T4), fallow and double cropping rice (C...