机构地区:[1]湖南大学研究生院隆平分院,湖南长沙410125 [2]湖南省农业环境生态研究所,农业部长江中游平原农业环境重点实验室,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 [3]埃肯国际贸易(上海)有限公司,上海200120
出 处:《环境科学研究》2021年第10期2428-2437,共10页Research of Environmental Sciences
基 金:国家重点研发计划项目(No.2016YFD0800705);国家自然科学基金项目(No.42007118)。
摘 要:镉(Cd)污染稻田土壤已经严重威胁到粮食安全,常规化肥的滥用不仅会使土壤理化性质发生改变,还会造成土壤重金属污染.因此,为缓解水稻Cd胁迫、促进常规化肥的合理施用,分别在化肥全施和减施化肥30%的基础上,研究增施不同浓度Si肥对湖南省平江县和临武县两试验点水稻产量、品质以及土壤有效态Cd、Si和水稻Cd、Si含量的影响.与各自对照相比,增施Si肥300~600kg/hm^(2)使得平江县和临武县两试验点:①水稻产量和品质显著提升,化肥全施条件下水稻分别增产917.8~1643.1和1003.3~1503.4kg/hm^(2);减肥30%条件下,水稻分别增产1037.9~1345.0和1209.1~1834.9kg/hm^(2).②化肥全施和减肥30%条件下水稻成熟期土壤有效态Cd分别显著下降10.5%~22.1%和14.1%~27.0%;有效态Si含量分别显著上升4.0%~7.0%和0.1%~27.2%,土壤有效态Cd含量和有效态Si含量呈显著负相关(P<0.05).③不同处理下水稻糙米和茎叶Cd含量显著降低,而水稻糙米和茎叶的Si含量显著提高;在化肥全施条件下,随着Si肥用量的增加,两试验点糙米Cd含量降低11.7%~39.2%,减肥30%条件下糙米Cd含量降低29.5%~57.2%.土壤有效态Cd含量的下降和Si在水稻各部位的聚集是阻碍Cd向水稻籽粒运输的主要原因.研究显示,在减肥30%条件下,增施Si肥对降低水稻籽粒Cd含量、提高水稻产量和品质的综合效益较高,这为实现科技部国家重点研究计划“化肥农药减施增效技术应用研究”提供了一条有效解决途径以及有力的技术支持.The ubiquitous cadmium(Cd)-contaminated paddy soil has posed a major threat to food safety,especially in mining smelting-impacted regions.The abuse of conventional chemical fertilizers not only negatively affects the physical and chemical properties of soil,but also contribute to heavy mental buildup in soils.Therefore,to mitigate Cd biotoxicity to rice and encourage proper incorporation of chemical fertilizers,the effects of silicon(Si)fertilizer on rice yield and quality,as well as soil Cd Si availability and rice Cd Si accumulation were investigated with full or 30%reduction of fertilizers and the application of 300-600kg/hm^(2) Si fertilizers at two different Cd-contaminated sites in Pingjiang County and Linwu County,Hunan Province in this study.The results showed that:(1)The rice yield was enhanced by 917.8-1643.1kg/hm^(2) and 1003.3-1503.4kg/hm^(2) with 100%chemical fertilizer and 1037.9-1345.0 and 1209.1-1834.9kg/hm^(2) with 30%reduction of fertilizer compared with the control fertilization,respectively.(2)The soil available Cd at the two test sites decreased by 10.5%-22.1%and 14.1%-27.0%,respectively,while the soil available Si increased by 4.0%-7.0%and 0.1%-27.2%,respectively.It is important to note that the soil available Cd exhibited a significantly positive correlation with the soil available Si(P<0.05).(3)Under different Si fertilizer amendments,the remarkable decrease of Cd accumulation in rice grains,stems and leaves was confirmed,while the Si concentration in rice tissues increased.Specifically,rice grain Cd decreased by 11.7%-39.2%and 29.5%-57.2%with full and reduced fertilizer,respectively.In summary,the decrease of soil available Cd and the increase of rice Si concentration were the main reasons for the reduced Cd accumulation in rice.Our research results show that 30%reduction of chemical fertilizer and the application of Si fertilizer can be an effective way to reduce rice Cd accumulation and increase rice yield and quality,which will provide a win-win strategy for mitigating chemical fertili
分 类 号:X59[环境科学与工程—环境工程]
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