伴矿景天-水稻轮作及磷修复剂对水稻锌镉吸收的影响

Effects of Sedum plumbizincicola-Oryza sativa rotation and phosphate amendment on Cd and Zn uptake by O.sativa

采用盆栽试验,将锌镉超积累植物伴矿景天与镉低积累水稻中香1号轮作种植于重金属污染土壤,并向土壤添加钙镁磷肥和磷矿粉,研究两种磷修复剂对伴矿景天和镉低积累水稻生长及地上部重金属积累性的影响.盆栽试验结果表明,在轻污染土壤上施用50g·kg-1磷矿粉时伴矿景天地上部的Zn、Cd吸收量分别达到每盆11.5和0.79mg,效果好于施用4g·kg-1钙镁磷肥处理.在重金属污染土壤上种植伴矿景天使后茬水稻地上部Zn、Cd浓度上升,但钙镁磷肥的施用显著降低了水稻体内的Zn、Cd积累量.种植伴矿景天后添加钙镁磷肥稳定调控剂对土壤中水溶态及NH4OAc提取态Zn、Cd的稳定效果明显优于磷矿粉,且在高污染土壤上效果更佳.田间试验结果显示,施用钙镁磷肥不仅可增加水稻产量,且可一定程度上降低水稻地上部的Zn、Cd吸收量.

In a pot experiment,hyperaccumulator Sedum plumbizincicola and low-cadmium accumulating Oryza sativa cultivar＂Zhongxiang No.1＂were planted in rotation on a heavy metals-polluted soil,and calcium magnesium phosphate（Ca-P） and rock phosphate（P-R） were amended,aimed to study the effects of the rotation and phosphate amendment on the growth of the two plants and the zinc-and cadmium accumulation in their shoots.After the amendment of 50 g P-R·kg-1,the Zn and Cd uptake by S.plumbizincicola was 11.5 mg·pot-1 and 0·79 mg·pot-1,respectively,being significantly higher than that after the amendment of 4 g Ca-P·kg-1.After the planting of S.plumbizincicola,the Zn and Cd concentrations in ＂Zhongxiang No.1＂increased,but the amendment of Ca-P decreased the accumulation of Zn and Cd in rice shoot significantly.The rotation with S.plumbizincicola and the amendment of Ca-P and P-R could immobilize the Zn and Cd in the contaminated soil as indicated by the quantitative change of NH4OAc-extractable Cd and Zn,and the efficiency of amendment with Ca-P was better than that of amendment with P-R.Field trial showed that amendment with Ca-P could not only increase the rice yield,but also reduce the Zn and Cd accumulation in rice shoot to a certain extent.