秸秆还田配施石灰对水稻镉吸收累积的影响  

Effects of straw returning with different lime dosages on Cd accumulation in rice

作　　者：杨定清[1] 李霞[1] 周娅[1] 罗丽卉[1] 谢永红[1] 王棚[1] 李旭毅[2] YANG Ding-qing;LI Xia;ZHOU Ya;LUO Li-hui;XIE Yong-hong;WANG Peng;LI Xu-yi(Analysis and Testing Centre of Sichuan Academy of Agricultural Sciences,Chengdu 610066,China;Crop Research Institute of Sichuan Academy of Agricultural Sciences,Chengdu 610066,China)

机构地区：[1]四川省农业科学院分析测试中心,成都610066 [2]四川省农业科学院作物研究所,成都610066

出　　处：《农业环境科学学报》2021年第6期1150-1158,共9页Journal of Agro-Environment Science

基　　金：国家农产品质量安全风险评估项目(GJFP2019001);四川省农业科学院青年基金项目(2018FXCSZX);四川省科技计划项目(2017NZ0062,2019YFS0506)。

摘　　要：秸秆还田是提升土壤肥力、增加作物产量的重要措施,但存在增加稻米镉(Cd)含量的风险。为探索合理的秸秆资源利用方式,以成都平原稻麦轮作土壤为对象,设置秸秆不还田、秸秆还田及秸秆还田配施4个石灰施用水平(600、1200、1800、2400 kg·hm^(-2))等6个处理,研究秸秆还田配施不同量石灰对水稻Cd吸收累积的影响。结果表明,与秸秆不还田相比,秸秆还田稻米Cd含量提高了18.1%,土壤溶解性有机碳(DOC)含量、有效态Cd含量分别提高了28.5%~95.7%、7.7%~18.9%,且DOC含量差异达显著水平(P<0.05)。与秸秆还田相比,秸秆还田配施石灰可通过有效提高土壤pH(0.15~0.85个单位)、降低土壤DOC(6.6%~29.3%)和有效态Cd含量(11.4%~38.6%)等来降低稻米Cd含量(11.2%~44.9%),且稻米Cd含量随石灰用量的增加而降低直至平稳水平,其中以秸秆还田配施石灰1800 kg·hm^(-2)和2400 kg·hm^(-2)处理表现最佳(P<0.05),低于《食品安全国家标准食品中污染物限量》(GB 2762—2017)0.2 mg·kg^(-1)的标准限值。此外,秸秆还田配施石灰水稻产量增加3.3%~6.2%(P>0.05)。在本研究试验条件下,秸秆还田配施石灰的最佳用量为1800 kg·hm^(-2),既能兼顾水稻产量,又能保障稻谷、土壤生态安全。Straw returning is an important measure to improve soil fertility and increase crop yield,but there is a risk of increasing rice cadmium(Cd)concentration.In order to study the rational utilization of straw resources,a field experiment on straw returning combined with lime was conducted to evaluate the effects of different lime-straw treatments on Cd uptake.Treatments included no-straw returning,straw returning,and straw returning with four lime dosages(600,1200,1800 kg·hm^(-2),and 2400 kg·hm^(-2)).Compared with the no-straw returning treatment,the straw returning treatment increased rice Cd,soil dissolved organic carbon,and available Cd content by 18.1%,28.5%~95.7%,and 7.7%~18.9%,respectively.Compared with straw returning treatment,straw returning with lime treatments reduced rice Cd contents by 11.2%~44.9%through increasing soil pH by 0.15~0.85 units,reducing soil DOC and available Cd contents by 6.6%~29.3%and 11.4%~38.6%,respectively.Straw returning with lime at 1800 kg·hm^(-2)and 2400 kg·hm^(-2)treatments significantly reduced rice Cd contents(P<0.05).With an increase in lime dosage,the rice Cd contents decreased to levels below 0.2 mg·kg^(-1),as recommended by the National Food Safety Standard-Limits of Contaminants in Food(GB 2762-2017).Moreover,straw returning with lime treatments increased rice yields by 3.3%~6.2%(P>0.05).With a careful consideration of environmental impacts and economic benefits,the combination of straw returning with 1800 kg·hm^(-2)lime is a high-yielding and ecologically safe intervention for straw resource utilization.

关 键 词：秸秆还田 石灰 水稻 CD 产量 

分 类 号：S141.4[农业科学—肥料学] X71[农业科学—农业基础科学]