持续淹水和干湿交替预培养对2种水稻土中Cd形态分配及高丹草Cd吸收的影响

采用盆栽试验的方法,研究了前期持续淹水和干湿交替预培养对2种水稻土———太湖地区黄泥土、江西鹰潭红壤性水稻土中外源Cd形态分配及高丹草吸收Cd的影响.结果表明,在5mg·kg^-1和10mg·kg^-1外源Cd处理下,与干湿交替预培养比较,持续淹水预培养后黄泥土中MgCl₂提取态Cd分别由21.8%、28.5%下降为8.0%、16.9%,而NH₂OH.HCl提取态Cd由17.7%、17.3%升高为28.1%、37.5%;红壤性水稻土NaAc提取态Cd由20.8%、29.6%下降为11.6%、12.6%.回归分析表明,MgCl₂提取态Cd与高丹草Cd吸收量呈显著负相关关系.长期淹水预培养显著降低高丹草对黄泥土Cd的吸收.

Effect of Submerging and Wetting-Redrying on Cd Speciation and Uptake by Sorghum Hybrid Sudangrass in Two Paddy Soils Under Spiked Cd

Effect of continuous submerging and wetting-redrying on cadmium speciation and uptake by Sorghum hybrid Sudangrass in a Ferric-accumulic Stagnic Anthrosol and a Tipical Hapludult collected from the Taihu Lake region and the rolling downs of Yingtan,Jiangxi,China respectively,was studied by pot experiment with Cd spike in 2003.Compared to that under wetting-redrying treatment,the MgCl₂-extracted pool of Cd in Huangnitu with spiked Cd of 5mg·kg^-1 and 10mg·kg^-1 was decreased from 21.8% and 28.5% to 8.0% and 16.9% while NH₂OH·HCl-extracted pool increased from 17.7% and 17.3% to 28.1% and 37.5% under continuous submerging.However,in the Typical Halpudult,NaAC-extracted pool of Cd decreased from 20.8% and 29.6% to 11.6% and 12.6%.Cd uptake by Sorghum hybrid Sudangrass was found in negative correlation with the MgCl₂ extracted pool of Cd.Total Cd uptake was significantly reduced by the pretreatment of continuously submerging in Huangnitu.