钝化剂抑制南方污染农田籽粒苋吸收重金属的效应研究  

Reduction of Heavy Metal Uptake by Amaranth by 3 Soil Amendments in Contaminated Farmland of South China

作　　者：肖艳辉[1] 李应文 邹碧[2] 何金明[1] 李志安[2,3] XIAO Yanhui;LI Yingwen;ZOU Bi;HE Jinming;LI Zhian(College of Biological and Agricultural,Shaoguan College,Shaoguan,Guangdong,512005,China;South China Botanical Garden,Chinese Academy of Science,Guangzhou 510650,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China)

机构地区：[1]韶关学院英东生物与农业学院,广东韶关512005 [2]中国科学院华南植物园,广东广州510650 [3]南方海洋科学与工程广东省实验室(广州),广东广州511458

出　　处：《生态环境学报》2021年第4期825-833,共9页Ecology and Environmental Sciences

基　　金：广东省科技计划项目(2018B030324003);南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0408);广州市科技计划项目(201903010022);国家重点研发计划(2016YFD0800704);韶关市土壤污染防治科技专项项目(2017sgtyfz303)。

摘　　要：华南地区历史悠久的矿冶业导致了较为严重的农田重金属污染问题,利用钝化剂抑制农作物吸收重金属并确保农产品安全是目前污染农田治理上的可行对策。文章评估钝化剂减少籽粒苋牧草吸收重金属的效果,探讨本地区受污染农田种植该牧草的安全技术。采集广东省乐昌市采矿污染农田土壤,盆栽种植籽粒苋(Amaranthus hypochondriacus L.),分别添加硅酸钙、石灰、硅钙镁肥3种钝化剂(各0.5%、1%剂量),测定籽粒苋生长量、叶片光合参数、重金属与矿质养分含量,评估钝化剂抑制籽粒苋吸收重金属及对植株生长的影响。结果表明,3种钝化剂均显著提高土壤pH,使土壤有效态重金属含量显著下降,除硅酸钙外,重金属钝化率普遍在90%以上;能使籽粒苋株高显著提高,除硅酸钙和0.5%硅钙镁肥外,生物量显著增加,而根冠比无显著变化;能显著改善植物色素含量和光合生理状况;石灰与硅钙镁肥能显著降低籽粒苋体内重金属含量,降低幅度与土壤重金属钝化率密切相关;石灰显著增加植株地上部对钙的吸收,硅钙镁肥显著增加植株地上部对镁的吸收,但石灰与硅钙镁肥均显著抑制植株地上部对锰的吸收。籽粒苋生长结束后,添加石灰和硅钙镁肥的土壤pH仍显著高于对照,有效态重金属含量显著低于对照,但与种植初期相比,有效态重金属含量均有所升高,土壤pH均有所下降,因此钝化剂具有一定的时效性。在重金属污染土壤中添加钝化剂能显著促进籽粒苋生长,显著降低其地上部对重金属的吸收累积,并以1%石灰效果最好。In south China,intensive mining activity has resulted in farmland contamination by heavy metals.Metal immobilization amendments,which could reduce crop uptake of heavy metal,play an important role in coping with contaminated farmland.This study evaluates effect of 3 soil amendments on reduction of heavy metal uptake by fodder grass,Amaranthus hypochondriacus L,aiming at producing qualified forage in contaminated land.An acid soil(pH 3.61)from farmland near mining site of Lechang City,Guangdong Province was collected.Pot experiment with amaranth(A.hypochondriacus)was set up.Three amendments including lime,calcium silicate(CaSi),silicon calcium magnesium fertilizer(SiCaMg)were applied to the plants at rates of 0.5%and 1%.A series of parameters of plant growth,photosynthesis,heavy metal content was determined.Soil amendments markedly decreased availability of heavy metals,by a magnitude of>90%except for CaSi,which were mainly attributed to soil pH rising.Soil amendments also largely increased amaranth growth,with effect of lime>SiCaMg>CaSi.Acidity reduction by amendments mainly contributed to the growth effect.Photosynthesis pigments,photosynthesis efficiency(Pn),transpiration rate(Tr),stomatal conductance(Gs)were all improved by the amendments.Lime and SiCaMg largely reduced heavy metal uptake by amaranth,with lime by more than 90%.CaSi had little effect.Reduction of heavy metal content in plant was significantly correlated with immobilization efficiency of heavy metal by soil amendments.Lime and SiCaMg increased Ca and Mg uptake,but decreased Mn uptake.At the end of plant growth,soil pH decreased,coupling with heavy metal availability increasing by comparison with the initial stage.However,soil amendments still resulted in a lower metal availability,compared to the control.In summary,lime and SiCaMg fertilizer could increase amaranth growth and markedly reduce heavy metal uptake,with best effect by 1%lime.

关 键 词：籽粒苋 酸性水稻土 重金属污染 植株生长 重金属钝化 

分 类 号：X171.5[环境科学与工程—环境科学] X173