紫云英-赤泥联合修复对中轻度镉污染稻田土壤性质和水稻产量的影响

Effects of the application of combined remediation of Chinese milk vetch and red mud on soil properties and rice yield in moderate and mild cadmium polluted paddy field

通过盆栽试验,研究了紫云英(Astragalus sinicus L.,CMV)-赤泥(RM)联合修复对中轻度镉污染稻田土壤性质和水稻产量的影响。结果表明,在水稻不同生育期,联合修复法CMV-RM1和CMV-RM2处理的土壤p H值增幅均低于RM1和RM2处理。在整个生育期内,CMV-RM1和CMV-RM2处理的pH值高于对照,差异均达显著水平(P<0.05),但CMV-RM1与CMV-RM2处理间差异不显著。不同时期CMV-RM1和CMV-RM2处理的土壤有机质、阳离子交换量、碱解氮含量均较其它处理高,但CMV-RM1与CMV-RM2处理之间差异不显著。与对照、单纯添加赤泥处理(RM1、RM2)以及翻压紫云英处理CMV相比,CMV-RM2、CMV-RM1处理的株高、有效穗数、每穗粒数、结实率、千粒重、产量均高于其他处理,但CMV-RM2、CMV-RM1处理之间差异均不显著。因此,与单独添加赤泥或单纯翻压紫云英修复相比,CMV-RM联合修复是修复镉污染酸性水稻土的一种经济、高效、可重复的修复方法。从既达到修复效果,又尽可能减少化学修复剂使用量上考虑,建议采用CMV-RM1处理。

A pot experiments were conducted to study the effects of the application of combined remediation of Chinese milk vetch(Astragalus sinicus L.,CMV)and red mud(RM)on soil properties and rice yield in moderate and mild cadmium polluted paddy fields.The results showed that in the whole growth period,the increase of soil pH value of CMV-RM1 and CMV-RM2 treatments was lower than that of RM1 and RM2.The pH values of CMV-RM1 and CMV-RM2 treatments were significantly higher than that of the control treatment,with significant differences(P<0.05).However,there was no significant difference between CMV-RM1 and CMV-RM2 treatments.Compared with the control,the content of soil organic matter,cation exchange capacity and alkaline nitrogen in CMV-RM1 and CMV-RM2 treatments in different periods were higher than those of other treatments.There was no significant difference between CMV-RM1 and CMV-RM2 treatments.Compared with the control,RM1,RM2 and CMV treatments,the combined remediation improved the yield components and grain yield.The plant height,effective panicles,grains perpanicle,seed setting rate,1000-grain weight and yield of CMV-RM2 and CMV-RM1 treatments were higher than those of other treatments,but there was no significant difference between CMV-RM1 and CMV-RM2 treatment.Therefore,compared with adding red mud alone or simply turning over milk vetch,the combined remediation of CMV-RM treatments is an economic,efficient and repeatable method for the remediation of cadmium contaminated acid paddy soil.Considering the remediation effect and minimizing the amount of chemical repair agent,CMV-RM1 treatment is recommended.