不同形态硫对水稻吸收积累镉的影响  

Effects of different sulfur forms on cadmium uptake and accumulation in paddy rice

作　　者：刘颖 苏广权 郭湘 杨燕花[2,3] 姚爱军[1] 仇荣亮[2,3,4] 汤叶涛 LIU Ying;SU Guang-quan;GUO Xiang;YANG Yan-hua;YAO Ai-jun;QIU Rong-liang;TANG Ye-tao(School of Geography and Planning,Sun Yat-sen University,Guangzhou 510275,China;School of Environmental Science and Engineering,Sun Yat-sen University,Guangzhou 510275,China;Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology,Sun Yat-sen University,Guangzhou 510275,China;Lingnan Modern Agricultural Science and Technology Guangdong Laboratory,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]中山大学地理科学与规划学院,广州510275 [2]中山大学环境科学与工程学院,广州510275 [3]中山大学广东省环境污染控制与修复重点实验室,广州510275 [4]岭南现代农业科学与技术广东省实验室,华南农业大学,广州510642

出　　处：《农业环境科学学报》2021年第6期1208-1218,共11页Journal of Agro-Environment Science

基　　金：国家重点研发计划项目(2018YFD0800700);国家自然科学基金项目(41877121)。

摘　　要：为探究不同形态硫素(SO42-/S2-)对水稻生物量和糙米Cd积累的影响,采用金属矿区下游Cd、As重度污染农田耕层土壤,以温室水稻盆栽试验,在施用足量CaCO_(3)条件下,向供试土壤中分别施加0(CK)、400 mgS·kg^(-1)(K_(2)S/K_(2)SO_(4))并持续淹水直至收获。结果表明:与CK相比,K_(2)S和K_(2)SO_(4)处理显著提高水稻总生物量130.1%~186.7%,且K_(2)S处理增加糙米产量效果更佳。与CK相比,施加S素能显著降低糙米Cd含量,K_(2)S处理使糙米Cd含量降低37.5%~50.0%,K_(2)SO_(4)处理降低31.3%~45.0%。两种施S处理均使糙米Fe含量下降90%以上。K_(2)S和K_(2)SO_(4)处理使土壤溶液pH平均降低0.28~0.32个单位,K_(2)S处理可显著促进土壤Cd向铁锰氧化物结合态和有机硫化物结合态Cd转化,铁锰氧化物结合态Cd在酸化和氧化环境下相对稳定,有利于稳定土壤Cd活性;K_(2)S处理同时增加茎、叶的S含量,有效将Cd液泡区隔化,将Cd固定在茎、叶,从而降低糙米Cd含量。K_(2)SO_(4)处理促进土壤Cd向碳酸盐结合态和有机硫化物结合态转化,在土壤酸化和Eh回升条件下,K_(2)SO_(4)处理土壤有效态Cd显著提高。但K_(2)SO_(4)处理比K_(2)S处理更有利于Cd在植物体内的液泡区隔化,这可能是其能够抑制Cd从根向地上部及籽粒转运的原因。研究表明,在施用足量CaCO_(3)条件下,足量施用K_(2)S或K_(2)SO_(4)均可提高水稻生物量,并有效降低糙米Cd含量。To explore the effects of different forms of sulfur(SO42-/S2-)on rice biomass and Cd accumulation in brown rice,pot experiments were performed by adding 0(CK)or 400 mg S·kg^(-1)(K_(2)S/K_(2)SO_(4))to farmland soil heavily contaminated with Cd and As.Soil samples were collected downstream from a metal mine in Guangdong Province.All tested soil samples were neutralized by CaCO_(3)under continuous flooding conditions.Compared to CK,K_(2)S and K_(2)SO_(4)treatments significantly increased total rice biomass by 130.1%~186.7%,but K_(2)S treatment resulted in a greater increase in brown rice yield.The Cd content of brown rice was reduced by 37.5%~50.0%after K_(2)S treatment and by 31.3%~45.0%after K_(2)SO_(4)treatment.The Fe content of brown rice in both sulfur treatment groups also decreased by over 90%.K_(2)S treatment inhibited the availability of Cd in the soil by promoting its transformation into Fe/Mn-oxide-bound and organicsulfide-bound forms of Cd.Moreover,K_(2)S treatment increased the S content of stems and leaves,which effectively sequestrated Cd into the vacuoles of stems and leaves,thus helping to reduce Cd translocation to the rice grain.Due to the increase in carbonate-bound and organic-sulfide-bound Cd formation,the amount of Cd available in the soil increased significantly after K_(2)SO_(4)treatment under soil acidification and elevated reduction potential conditions.However,K_(2)SO_(4)treatment was more effective than K_(2)S treatment at sequestrating Cd into the vacuoles,which helped to limit Cd translocation to the shoot and grain.These results show that,after the adequate application of CaCO_(3),both tested sulfur forms,at their full dose,effectively reduce Cd content in brown rice and increase rice yield.

关 键 词：水稻 S形态 K2SO4 K2S 镉 

分 类 号：S511[农业科学—作物学] X53[环境科学与工程—环境工程]