不同种类的氮肥对籽粒苋富集镉的影响

Effects of Different Nitrogen Fertilizers on Cd Enrichment in Amaranthus hypochondriacus L.

为研究施肥对超富集植物的重金属累积效果产生影响,以籽粒苋为研究对象,根据土壤环境质量标准设置镉浓度梯度分别为0、2.4、4.8、9.6 mg/kg,然后施以铵态氮和硝态氮两种肥料。研究结果表明:各处理下,籽粒苋叶Cd含量最高,为1.45~27 mg/kg;茎次之,为0.90~17.15 mg/kg。肥料类型对籽粒苋Cd的累积量未产生显著影响,但肥料浓度对籽粒苋Cd的累积具有显著差异(F=12.993,P<0.01);当铵态氮肥施用浓度分别为0.115、0.460 mg/kg时,籽粒苋茎、叶Cd含量最大,分别为17.15、27.00 mg/kg。土壤Cd含量受Cd添加浓度的影响,氮肥施用浓度和Cd添加浓度对土壤Cd含量具有显著的交互作用(F=3.382,P<0.01)。籽粒苋茎和叶对Cd的累积系数具有显著差异(F=19.679,P<0.01),Cd的处理浓度对籽粒苋地上部累计系数有显著影响(F=12.362,P<0.01)。综上可知,施用适量浓度的铵态氮肥有助于籽粒苋Cd的富集,可用于土壤Cd污染的修复。

The effect of fertilization on the accumulation of heavy metals in hyperenriched plants is significant to the field application of hyperenriched plants.Aamaranthus hypochondriacus L.was taken as the research object,cadmium concentration gradients 0,2.4,4.8,and 9.6 mg/kg were set according to soil environmental quality standards,and then ammonium nitrogen and nitrate nitrogen were applied.Results show that first,under each treatment,the Cd content of A.hypochondriacus leaves was the highest,ranging from 1.45~27 mg/kg,and it was 0.90~17.15 mg/kg in stems.Fertilizer type had no significant effect on the Cd accumulation in A.hypochondriacus,but fertilizer concentration had significant difference on the Cd accumulation(F=12.993,P<0.01).When the concentration of ammonium nitrogen fertilizer was 0.115 mg/kg and 0.460 mg/kg,the content of Cd in the stem and leaf was the highest,which were 17.15 and 27.00 mg/kg,respectively.Secondly,the content of soil Cd was affected by the added concentration of Cd,but there was a significant interaction between the application concentration of nitrogen fertilizer and the added concentration of Cd(F=3.382,P<0.01).Thirdly,there was a significant difference in the accumulation coefficient of Cd between the stem and leaf(F=19.679,P<0.01),and the concentration of Cd had a significant effect on the accumulation coefficient in the top soil(F=12.362,P<0.01).In conclusion,application of appropriate concentration of ammonium nitrogen fertilizer could contribute to the enrichment of Cd in A.hypochondriacus,which could be used to repair soil Cd pollution.