不同改良剂对镉污染土壤的改良效果和对水稻光合特性的影响

采用盆栽试验,研究赤泥、石灰和海泡石对Cd污染土壤的改良效果和水稻光合特性的影响。结果表明:施赤泥、石灰和海泡石均能有效促进土壤交换态Cd的稳定,有利于Cd的固定,其中以赤泥对Cd的钝化效果最佳;与对照相比,赤泥处理的水稻增产幅度较大,为11.41%,海泡石处理的水稻产量略有提高,石灰处理的水稻产量略有下降;不同改良剂均能增加水稻剑叶的叶绿素含量(SPAD值)、气孔导度、净光合速率、胞间CO2浓度及蒸腾速率,其中以施赤泥处理效果最好,分别比对照提高6.63%、8.59%、6.93%、11.95%、5.42%;不同改良剂处理水稻剑叶面积均有不同程度的上升,添加赤泥更能缓解Cd污染对水稻生长的影响。

Effects of different soil amendments on the remediation of Cd-contaminated soil and the photosynthetic characteristics of rice plant

A pot experiment was conducted to study the effects of three amendments(red mud,lime and sepiolite)on remediation of Cd in Cd-contaminated paddy soil and photosynthetic characteristics of rice plant.The results indicated that application of red mud,lime and sepiolite could effectively promote the stabilization of soil exchangeable Cd and the immobilization of Cd with the red mud shown the best immobilization effect.Compared with the control,the application of red mud increased yield dramatically,by 11.41%,and the application of sepiolite slightly increased the yield,while the application of lime decreased the yield slightly.The application of soil amendments could improve chlorophyll content(SPAD value),the rice stomatal conductance(Gs),the net photosynthetic rate(Pn),intercellular CO2 concentration(Ci)and transpiration rate(Tr)of flag leaf of rice.Among the three amendments,the effect of application of red mud was most obvious,with which the SPAD value,Gs,Pn,Ci and Tr was respectively increased by 6.63%,8.59%,6.93%,11.95% and 5.42%.Three amendments all increased the flag leaf area,but the degree of increase varied.Compared with lime and sepiolite,red mud application could better alleviate the effect of Cd on rice growth.