滇东地质高背景区土壤镉的伴矿景天修复及其对后茬水稻的影响  

Phytoextraction of the Soils from the East of Yunnan Province with a High Cadmium Geological Background and Its Effect on Rice Cadmium Uptake

作　　者：吴拓铮 詹娟 周嘉文 周通 李柱[1] 胡鹏杰[1] 黄化刚 李廷轩 张锡洲 骆永明[1] WU Tuozheng;ZHAN Juan;ZHOU Jiawen;ZHOU Tong;LI Zhu;HU Pengjie;HUANG Huagang;LI Tingxuan;ZHANG Xizhou;LUO Yongming(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 211135,China;College of Resources,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]土壤与农业可持续发展全国重点实验室(中国科学院南京土壤研究所),南京211135 [2]四川农业大学资源学院,成都611130

出　　处：《土壤学报》2024年第5期1349-1359,共11页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(U2002210)资助。

摘　　要：云南是我国典型的重金属元素地球化学高背景区,超积累植物能否有效修复镉(Cd)地质高背景土壤,从而实现农产品安全生产,尚鲜见报道。以云南石林、富源和罗平等三地的典型Cd地质高背景农田土壤为对象,开展温室盆栽试验,探究Cd、锌(Zn)超积累植物伴矿景天对土壤Cd的吸取修复效果,及对后茬水稻生长和Cd吸收的作用。结果表明,种植三季伴矿景天使三地土壤全量Cd分别下降24.8%、30.9%和58.8%;伴矿景天在富源玄武岩风化物母质发育的土壤上长势最好,与富源土壤肥力相对最高有关;伴矿景天在罗平石灰岩风化物发育的土壤上重金属吸取修复效果最佳,与罗平土壤呈中性、酸化作用更为明显有关,这些差异由土壤母质、养分与重金属有效性等综合影响所致。经伴矿景天吸取修复三季后,全生育期淹水种稻,其糙米和秸秆Cd浓度均大幅降低,可实现糙米Cd安全生产。未经植物吸取修复,旱作处理下水稻糙米Cd存在超标风险。植物吸取修复后种植水稻,再结合水分管理措施,可进一步降低稻米中Cd浓度,实现稻米安全生产,为Cd地质高背景区土壤的农作物安全生产提供理论依据和技术支撑。【Objective】Yunnan Province is one of the typical high geological background regions in China.However,a few studies have focused on the phytoextraction of high geological soils for safe agricultural production.【Method】This research was conducted to investigate cadmium(Cd)phytoextraction efficiency of the high geological background soils from Shilin,Fuyuan,and Luoping in Yunnan Province by the Cd/zinc(Zn)hyperaccumulator Sedum plumbizincicola and its effect on plant growth and Cd uptake by rice(Oryza sativa)through pot experiments.【Result】After triple-cropping of S.plumbizincicola,the total Cd and available Cd concentrations in soils showed a substantial decrease,with the total Cd decreasing to 24.8%,30.9%,and 58.8%of the original values for soils from Shilin,Fuyuan,and Luoping,respectively.S.plumbizincicola showed better growth when grown in soils from Fuyuan developed from basalt with more soil nutrients but presented a greater Cd phytoextraction efficiency when grown in soils from Shilin developed from limestone with higher soil pH,thereby greater Cd mobilization capacity.These significant differences indicated that plant growth and heavy metal accumulation of hyperaccumulators were affected by the comprehensive effects of soil parent materials,soil nutrients,and heavy metal availability in soils.After a triple-cropping of S.plumbizincicola,Cd concentration in brown rice and rice straw was significantly decreased under flooding conditions through the whole growth period,resulting in a Cd-safe production.However,the rice grain possessed a high Cd pollution risk without phytoextraction when grown under a dry cultivation system.【Conclusion】The phytoextraction of high geological background soils by S.plumbizincicola combing with water management measures benefits greatly the safe production of rice crops,thereby providing a theoretical basis and technical support for the safe production of the high geological background soils.

关 键 词：土壤镉 地质高背景 植物吸取修复 水稻 水分管理 

分 类 号：X53[环境科学与工程—环境工程]