水稻整株移除提高镉污染稻田安全利用效果  

Rice whole-plant removal to improve safe utilization of cadmium-contaminated rice fields

作　　者：任巧瑞 李剑 石宏 吴珂萌 杨京民 陈荟林 于运萍 王欣[1,2,3] 彭渤 REN Qiaorui;LI Jian;SHI Hong;WU Kemeng;YANG Jingmin;CHEN Huilin;YU Yunping;WANG Xin;PENG Bo(College of Geographical Sciences,Hunan Normal University,Changsha 410081;Key Laboratory of Agricultural Environment in the Middle Reaches of the Yangtze River Plain,Ministry of Agriculture and Rural Affairs,Changsha 410125;Institute of Interdisciplinary Science,Hunan Normal University,Changsha 410006;Wugang City Agriculture and Rural Bureau,Wugang 422499)

机构地区：[1]湖南师范大学地理科学学院,长沙410081 [2]农业部农村部长江中游平原农业环境重点实验室,长沙410125 [3]湖南师范大学交叉科学研究院,长沙410006 [4]武冈市农业农村局,武冈422499

出　　处：《环境科学学报》2025年第1期334-344,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.42377024,41977108);湖南省地理学一流学科建设项目(No.地理学-5010002);湖南省高校优势特色学科群建设项目(No.2022XKQ0207);湖南省普通高等学校科技创新团队支持项目。

摘　　要：为探索中轻度Cd污染稻田的安全利用路径,本研究对比利用不同水稻品种专性移除作物有效态Cd,提取修复后对土壤进行调碱补硅,以明确“清洁减量-调理降活”的协同策略对降低稻米Cd积累的作用.2021年大田试验,采取湿润水分管理方式(土壤表面无明显水)分别种植杂交稻(桃优香占)和常规稻(玉针香)两个高Cd积累水稻品种进行土壤有效Cd专性提取并进行整株移除;在次年大田试验,采取常规水分管理种植当地食用杂交稻(Y两优9918),通过单施石灰(CaO)和石灰复配稻壳灰(CaO+RHA)调碱土壤pH和增加土壤有效Si含量,强化水稻安全生产效果.结果表明:(1)采用湿润水分管理模式,种植桃优香占和玉针香对土壤Cd赋存形态表现出显著差异,玉针香使作物易利用态Cd含量(可交换态+碳酸盐结合态)与相对稳定态Cd含量(铁锰氧化物结合态+有机结合态+残渣态)分别降低11%和14%;桃优香占则使其分别降低2%和29%.(2)整株移除玉针香和桃优香植株后,与未进行提取处理的田块相比,Y两优9918稻米Cd由1.02 mg·kg^(-1)降至0.85~0.92 mg·kg^(-1),降幅为10%~18%.提取修复后,单施CaO使稻米Cd含量降低73%~82%;CaO+RHA处理下稻米Cd含量进一步降低26%~71%,其中,经桃优香占提取修复后的田块,施用CaO或CaO+RHA均使稻米Cd达到国家食品安全标准.因此,该地区可在湿润水分模式下种植桃优香占并整株移除减少土壤Cd存量,针对提取修复后的土壤,可结合土壤调碱补硅等必要措施强化控制水稻Cd积累,保障水稻安全生产.In order to explore pathways toward safe rice production in paddy fields with moderate to light Cd contamination,this study investigated the specific depletion of crop-available Cd by different rice cultivars which was then complemented by measures for soil liming and silicon(Si)supplement.We aimed to identify the effect of this synergistic strategy coupling Cd depletion with follow-up immobilization on mitigating rice Cd accumulation.In the field experiment in 2021,two high Cd-accumulating cultivars,ie.hybrid rice(TaoyouXiangzhan)and conventional rice(Yuzhenxiang),were planted under saturated moisture condition with no visible floodwater for soil Cd extraction.In the following field experiment next year,local edible hybrid rice(Y liangyou 9918)was cultivated under conventional water management,with calcium oxide(CaO)alone or combined CaO and rice husk ash(CaO+RHA)applied to further secure rice production by raising soil pH and enhancing effective Si level.The results showed that:(1)under moisture water management,TaoyouXiangzhan and Yuzhenxiang exerted a significantly distinct impact on soil Cd fraction.In specific,Yuzhenxiang depleted Cd from readily available(exchangeable+carbonate-bound)and more stable(iron-manganese oxide bound+organically bound+residual)fractions by 11%and 14%,respectively,as compared to 2%and 29%by TaoyouXiangzhan.(2)Compared with the unextracted soil,grain Cd of edible Y-liangyou 9918 decreased by 10%~18%from 1.02 mg·kg^(-1)to 0.85~0.92 mg·kg^(-1)in the post-extracted fields with the whole rice plants removed.In the post-extracted soil,grain Cd content was reduced by 73%~82%with CaO alone,which was further diminished by 26%~71%under the treatment of CaO+RHA.Particularly,with synergistic application of either CaO or CaO+RHA,grain Cd level in the fields subjected to phytoextraction with TaoyouXiangzhan fell within the national food safety standards.Therefore,to achieve safe utilization of strictly controlled acidic paddy soils,phytoextraction with Taoyouxiangzhan rice cultivars under satu

关 键 词：水稻 根系移除 石灰(CaO) 稻壳灰(RHA) 稻田 镉(CD) 提取 

分 类 号：X53[环境科学与工程—环境工程]