摘要
为研究硅肥对土壤Cd生物有效性以及水稻累积重金属Cd的影响,模拟土壤低Cd污染水平(Cd总量为0.72mg·kg^(-1))和土壤高Cd污染水平下(Cd总量为5.08 mg·kg^(-1)),土壤基施0、15、30、60 mg·kg^(-1)的硅肥,进行水稻盆栽种植实验.结果表明,施用15~60 mg·kg^(-1)硅肥能提升水稻各生育期土壤的pH值,降低土壤交换态Cd含量和TCLP提取态Cd含量24.2%~43.7%,12.7%~46.8%,土壤中Si能与Cd形成Si-Cd复合物,降低土壤Cd的生物有效性,且降低效果在土壤低Cd污染水平时优于高Cd污染水平.硅肥提升水稻地上部的生物量尤其是产量.土壤低Cd污染水平下,Si对土壤Cd向水稻地上部的转运有促进和阻碍两种作用,施用量过低(Si 15 mg·kg^(-1))或过高(Si 60 mg·kg^(-1))时均促进土壤Cd向水稻地上部转运,施用量为30 mg·kg^(-1)时则阻碍Cd向上转运.随着Si施用量的增大,糙米Cd含量先上升后下降,范围为0.07~0.15 mg·kg^(-1),均低于0.2 mg·kg^(-1).土壤高Cd污染水平下,Si阻碍Cd向水稻地上部的转运,糙米、谷壳、茎叶的Cd含量分别降低38.7%~48.5%、35.7%~70.7%、30.9%~40.7%,糙米Cd含量范围0.23~0.28 mg·kg^(-1).综合考虑产量和糙米Cd含量,土壤低Cd污染水平下,建议施用30 mg·kg^(-1)的Si;高Cd污染水平下,建议施用Si 15~60 mg·kg^(-1).
The impacts of silicon （Si） on cadmium （Cd） bioavailability in soil and Cd accumulation in rice plants were investigated in pot experiments with rice （Oryza satiυa L. ） cultivation. Silicon fertilizer as the base manure （Si 0, 15, 30, and 60 mg·kg - 1 ） was added in simulated slightly Cd-contaminated soil （total soil Cd of 0. 72 mg·kg - 1 ） and severe Cd-contaminated soil （total soil Cd of 5. 08 mg·kg - 1 ）. It indicated that the application of 15-60 mg·kg - 1 Si before the rice was transplanted improved soil pH values and reduced the contents of exchangeable-Cd and TCLP extractable-Cd in the soil by 24. 2% -43. 7% and 12. 7% -46. 8% , respectively, during the rice growing stages. The reduction in soil Cd bioavailability resulted from the complexing of Si and Cd, and the reduction followed the order： slightly Cd-contaminated soil 〉 severely Cd-contaminated soil. It was obvious that silicon fertilizer improved rice biomass above ground, especially for rice grain yield. In the slightly Cd-contaminated soil, Si both promoted and restrained soil Cd transportation from the rice root to the shoot; the low application （Si 15 mg·kg - 1 ） and high application （Si 60 mg·kg - 1 ） of Si both promoted Cd transportation, but the medium application （ Si 30 mg·kg - 1 ） restrained Cd transportation. With increasing silicon fertilizer application, Cd contents in brown rice increased first and then decreased, ranging from 0. 07-0. 15 mg·kg - 1 , remaining lower than 0. 2 mg·kg - 1 . In the severely Cd-contaminated soil, Si restrained the soil Cd transportation from the rice root to the shoot. The Cd contents in brown rice, husk, and straw were reduced by 38. 7% -48. 5% , 35. 7% -70. 7% , and 30. 9% -40. 7% , respectively, and Cd contents in brown rice were 0. 23-0. 28 mg·kg - 1 . Considering rice grain yields and Cd contents in brown rice, it was recommended that the Si application be 30 mg·kg - 1 of Si in the slightly Cd-contaminated soil and Si 15-60 mg·kg - 1 in the severely Cd-contaminated soil.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2017年第12期5299-5307,共9页
Environmental Science
基金
农业部财政部科研专项(农办财函2016)
国家自然科学基金项目(41501344)
关键词
硅肥
生物有效性
累积
镉污染
土壤
水稻
silicon fertilizer
bioavailability
accumulation
Cd contamination
soil
rice
作者简介
高子翔（1992-），男，硕士研究生，主要研究方向为土壤重金属污染与控制，E-mail：owen_544013802@qq．com;通信作者，E-mail：liaobh1020@163．com
