岩溶区镉污染棕色石灰土母质稻田土壤团聚体镉赋存特性研究  

Occurrence form of cadmium in soil aggregates in cadmium⁃contaminated brown calcareous soil parent material paddy field in karst area

作　　者：黄雁飞[1] 钟蕙镁 刘淑仪[1] 熊柳梅[1] 聂雄峰 陈韦韦[2] 刘斌[1] HUANG Yan-fei;ZHONG Hui-mei;LIU Shu-yi;XIONG Liu-mei;NIE Xiong-feng;CHEN Wei-wei;LIU Bin(Agricultural Resources and Environmental Research Institute,Guangxi Academy of Agricultural Sciences/Guangxi Key Laboratory of Arable Land Conservation,Nanning 530007,China;Rice Research Institute,Guangxi Academy of Agricultural Science,Nanning 530007,China)

机构地区：[1]广西农业科学院农业资源与环境研究所/广西耕地保育重点实验室,南宁530007 [2]广西农业科学院水稻研究所,南宁530007

出　　处：《西南农业学报》2024年第2期412-419,共8页Southwest China Journal of Agricultural Sciences

基　　金：广西自然科学基金项目(2020GXNSFBA297041);广西创新驱动发展专项(桂科AA22036001⁃3);广西农业科学院基本科研业务专项(桂农科2024YP044,桂农科2021YT042);广西重大科技创新基地广西水稻遗传重点实验室自主创新课题(2022⁃36⁃Z01⁃ZZ01)。

摘　　要：【目的】研究桂西北岩溶区镉(Cd)污染棕色石灰土母质稻田土壤团聚体Cd赋存形态特性,为区域内该类型Cd污染稻田稻米安全生产提供数据参考。【方法】采用湿筛法将采样土壤团聚体分离成>2.000 mm、1.000~2.000 mm、0.250~1.000 mm、0.074~0.250 mm和<0.074 mm 5个粒级的团聚体,研究桂西北岩溶区0~20、20~30、30~50和50~80 cm剖面深度土壤团聚体粒径组成、不同粒径团聚体Cd含量及其主要赋存形态。【结果】各层剖面0.250~1.000 mm粒径团聚体占比较为稳定,均在30.00%以上,各层剖面间无显著差异(P>0.05)。0~20 cm剖面(耕作层)中>2.000 mm粒径团聚体占比最大(40.20%),随着剖面深度增加,>2.000 mm粒径团聚体占比迅速降低,<0.250 mm粒径团聚体占比呈逐渐增加趋势。不同粒径团聚体Cd含量分析结果表明,在0~20、20~30和30~50 cm剖面中,Cd主要富集在>2.000 mm粒径团聚体中,Cd含量分别高达2.22、1.66和0.95 mg/kg,在50~80 cm剖面中,Cd主要富集在1.000~2.000 mm粒径团聚体中。>2.000 mm粒径团聚体在0~30 cm土层中对全土Cd含量的贡献率最大。不同剖面深度团聚体中Cd赋存形态存在明显差异,0~20 cm剖面各粒径团聚体中Cd主要以有机结合态存在,可交换态Cd占比最小(<0.074 mm粒径团聚体除外),随着剖面深度增加,团聚体中可交换态Cd占比明显增加,当剖面深度增加至30 cm以下时,团聚体中Cd主要以碳酸结合态存在,残渣态含量最小。【结论】桂西北岩溶区Cd污染棕色石灰土母质稻田Cd主要富集在>2.000 mm和1.000~2.000 mm粒径的团聚体中;0~20 cm耕作层各粒径团聚体中的Cd主要以有机结合态存在,可交换态占比最小,随着剖面深度的增加,可交换态Cd占比明显增加,稳定形态Cd占比明显降低。因此,在实际生产过程中要注重提高土壤大粒径团聚体含量,避免过度精耕和深翻,减少耕层土壤可交换态Cd含量,降低水稻生产过程中稻米Cd超标的风险。【Objective】The present paper aimed to study the occurrence form of cadmium(Cd)accumulation in soil aggregates of Cd⁃contami⁃nated brown calcareous soil matrices of paddy fields in the Karst area of northwestern Guangxi,and to provide data reference for safe rice production in this type of Cd⁃contaminated paddy fields in the region.【Method】The sampled soil aggregates were separated into five aggregates as>2.000 mm,1.000-2.000 mm,0.050-1.000 mm,0.074-0.250 mm and<0.074 mm,the composition of soil aggregates parti⁃cle size,Cd content of different particle size aggregates and their main occurrence patterns from 0-20,20-30,30-50 and 50-80 cm depth profiles in the Karst area of northwest Guangxi were studied.【Result】The proportion of 0.250-1.000 mm size aggregates in each pro⁃file was stable,above 30.00%,with no significant difference between profiles(P>0.05),the proportion of>2.000 mm size aggregates in the 0-20 cm soil profile(tillage layer)was the largest(40.20%),and as the depth of the profile increased,the proportion of>2.000 mm size aggregates decreased rapidly,and the proportion of<0.250 mm size aggregates showed a gradual increasing trend.Analysis of the Cd content of agglomerates of different particle sizes showed that,in 0-20,20-30 and 30-50 cm soil profiles,Cd was mainly enriched in>2.000 mm particle size aggregates,with contents as high as 2.22,1.66 and 0.95 mg/kg,respectively,and in the 50-80 cm soil profile,Cd was mainly enriched in 1.000-2.000 mm particle size aggregates.>2.000 mm particle size aggregates contributed most to the whole soil Cd content in the 0-30 cm soil layer.The occurrence form of Cd in the aggregates at different profile depths showed obvious differ⁃ences,the proportion of Cd in aggregates of all particle sizes in the 0-20 cm profile was mainly in the organic matter binding state,with the smallest proportion of Cd in the exchangeable state(except for<0.074 mm particle size aggregates),and the proportion of Cd in the ex⁃changeable state in the aggregates increas

关 键 词：镉污染 棕色石灰土 稻田 土壤团聚体 镉赋存形态 

分 类 号：S511[农业科学—作物学]