大田条件下石灰降低水稻镉累积效果研究  

Study on the Effect of Lime on Reducing Cadmium Accumulation in Rice under Field Conditions

作　　者：刘敏 孟晓琦 刘伟 LIU Min;MENG Xiaoqi;LIU wei(Qingdao Ecological and Environmental Monitoring Center,Shandong Province,Qingdao 26600,China)

机构地区：[1]山东省青岛生态环境监测中心,山东青岛266000

出　　处：《环境影响评价》2022年第3期68-74,共7页Environmental Impact Assessment

摘　　要：本研究采用田间试验,在某镉污染地区研究石灰调节土壤pH降低稻米镉积累的效果,以降低镉食物链暴露途径的风险。根据RothLime模型试验共设置4个石灰剂量处理(0、2.25、4.50、7.50 t∕ha),种植两个水稻品种。得到如下研究结果:石灰(2.25~7.50 t∕ha)在2018年一次性施用,最高剂量(7.50 t∕ha)的石灰使土壤pH由初始的5.5上调至6.5左右。施用石灰可提高根际土壤pH、降低CaCl2可提取的镉含量和稻米镉含量;籽粒镉含量与水稻成熟期根际土壤中CaCl2可提取的镉含量显著相关;当一次性施用7.50 t∕ha石灰时,水稻籽粒镉含量降低了77%~80%,连续三年稻米镉含量低于我国食品安全标准(0.2mg∕kg),并且产量未受影响。本田间试验结果表明,单次施用CaCO_(3)使土壤pH上调至6.5,能显著降低水稻籽粒镉的积累。A field experiment was conducted to study the effect of lime regulating soil pH to reduce cadmium accumulation in rice in order to reduce the risk of cadmium exposure in cadmium food chain in somewhere.According to the RothLime model test,four lime treatments(0,2.25,4.50,7.5 t∕ha)were set up,and two rice varieties were planted.The results are as follows:lime(2.25~7.50 t∕ha)was applied once in 2018,and the maximum dose(7.50 t∕ha)of lime increased the soil pH from 5.5 to 6.5.Lime application increased pH in rhizosphere soil,decreased CaCl2extractable cadmium content and rice cadmium content;grain cadmium content was significantly correlated with CaCl2extractable cadmium content in rice rhizosphere soil at mature stage;when 7.50 t∕ha lime was applied once,rice grain cadmium content decreased by 77%~80%,rice cadmium content was lower than Chinese food safety standard(0.2 mg∕kg)for three consecutive years,and rice yield was not affected.The results of field experiment showed that single application of CaCO_(3)increased soil pH to 6.5,which could significantly reduce the accumulation of cadmium in rice grains.

关 键 词：石灰 土壤镉污染 稻米镉含量 

分 类 号：X503.231[环境科学与工程—环境工程]