硅肥等量施用对土壤砷赋存形态和水稻吸收砷的影响  

Effects of Equal Amount of Silicon Fertilizer on Soil Arsenic Speciation and Arsenic Uptake by Rice

作　　者：吴家梅[1,2] 官迪 陈山[1,3] 谢运河 陈锦[1,3] 龙世平 纪雄辉[1,3] WU Jiamei;GUAN Di;CHEN Shan;XIE Yunhe;CHEN Jin;LONG Shiping;JI Xionghui(Hunan Institute of Agro-Environment Ecology,Hunan Academy of Agricultural Sciences,Key Laboratory of Agro-Environment in Midstream of Yangtze Plain,Ministry of Agriculture and Rural Affairs,Changsha 410125,China;Hunan Engineering Research Center for Prevention and Control of Agricultural Non-Point Source Pollution in the Basin of Lake Dongting,Changsha 410125,China;Key Laboratory of Hunan Province,Prevention,Control and Remediation of Heavy Meatal Pollution of the Farmlands,Changsha 410125,China)

机构地区：[1]湖南省农业科学院农业环境生态研究所,农业农村部长江中游平原农业环境重点实验室,湖南长沙410125 [2]湖南省洞庭湖流域农业面源污染防治工程技术研究中心,湖南长沙410125 [3]农田土壤重金属污染防控与修复湖南省重点实验室,湖南长沙410125

出　　处：《环境科学研究》2023年第9期1746-1754,共9页Research of Environmental Sciences

基　　金：国家重点研发计划项目(No.2022YFD1700105,2017YFD0801504);湖南省重点研发计划项目(No.2021NK2009)。

摘　　要：为研究施用不同种类硅肥对土壤砷(As)的生物有效性和不同生育期水稻As含量的影响,采用含钾(Si1),含钙、镁(Si2),含钙、镁和钾(Si3),含钙、镁和铁(Si4),以及水溶性硅肥(Si5)共5种不同种类相同用量的硅肥(SiO2用量为225 kg/hm2)开展田间小区实验,分析水稻不同生育期水稻As含量和土壤As含量.结果表明:①Si4和Si5处理降低糙米As含量的效果较好,分别比CK处理显著降低31.3%(P<0.05)和27.6%(P<0.05).②施用硅肥,水稻分蘖期和拔节期根表铁膜Fe(DCB-Fe)含量高于CK处理,灌浆期和成熟期DCB-Fe含量低于CK处理;施用硅肥处理水稻分蘖期、拔节期、灌浆期和成熟期的DCB-As含量均降低,分别比CK处理降低10.0%、27.0%、20.0%和29.5%.③施用硅肥条件下,与CK处理相比,水稻成熟期土壤非专性吸附态As(Nas-As)、结合态As(Al-As)和残渣态As(Res-As)的含量平均分别降低15.8%、9.8%和10.2%,铁结合态As(Fe-As)含量提高33.0%.④水稻成熟期,根系As含量和土壤有效态As含量影响稻米对As的吸收,土壤有效态硅含量影响水稻根系对As的吸收;整个生育期,水稻根表铁膜As和Fe显著影响水稻根系对As的吸收.施用硅肥条件下,土壤有效态Si含量提高,有效态As含量降低,Fe-As含量增加,成熟期水稻DCB-As含量降低,水稻植株对As的吸收量减少.研究显示,相同用量的硅肥中,硅的有效性高或添加铁素,对降低水稻吸收As的效果更好,可为As污染土壤的水稻安全生产利用提供有效的解决途径.In order to explore the effects of different silicon fertilizers on soil arsenic(As)bioavailability and As uptake by rice at different growth stages,field experiments were carried out with silicon fertilizers containing potassium(Si1),calcium and magnesium(Si2),calcium,magnesium and potassium(Si3),calcium,magnesium and iron(Si4)and water-soluble silicon(Si5).At the same application rate of SiO2(225 kg/hm2),the As accumulation in rice in the typical stages with corresponding soil As was determined,and the results demonstrated that:(1)The treatments Si4(including Si,Ca,Mg and Fe)and Si5(water soluble Si fertilizer)showed higher mitigation ability,decreasing As content in brown rice by 31.3%(P<0.05)and 27.6%(P<0.05),respectively,relative to control.(2)With Si treatment,iron content in root plaques(DCB-Fe)was higher at tillering stage and jointing stages than the control,but not at the filling and mature stages.After silicon application,the As content in iron plaques(DCB-As)decreased continuously throughout the rice growth period,and decreased by 10.0%,27.0%,20.0%and 29.5%at the tillering,jointing,filling and ripening stages,respectively.(3)As fractions of non-specifically absorbed,bound to aluminum and residual phase decreased by 15.8%,9.8%and 10.2%,respectively,while the content of As bound to iron increased by 33.0%in soils with silicon amendments.(4)As accumulation in roots and soil available As had major effects on As unloading into grains at the mature stage,and root As was affected by available silicon in soils.During the whole growth period,As and Fe in the iron plaques had a significant effect on root As uptake.Overall,the application of silicon fertilizers increased the content of soil available silicon and decreased soil available As by increasing the content of As bound to Fe(hydr)oxides,thereby reducing the content of plaque DCB-As and As uptake by rice plants.This research showed that at the same application rate of silicon fertilizers,higher silicon availability or additional iron tended to reduce As a

关 键 词：稻田 硅 As污染 根表铁膜 As形态 

分 类 号：X53[环境科学与工程—环境工程]