应用灰色关联法分析石灰配施有机肥对镉污染土壤-植物系统的影响

Grey relational analysis for evaluating the effects of lime combined with organic fertilizer on a cadmiumcontaminated soil-plant system

为缓解长期单施石灰对土壤的破坏,本研究以石灰配施有机肥为修复手段,采用盆栽试验,以无处理(CK)、单施有机肥(OF:3000 kg·hm^(-2))及单施石灰(FT:1500 kg·hm^(-2))为对照,设置3个石灰+有机肥配施处理(SO1:1500 kg·hm^(-2)+3000 kg·hm^(-2)、SO2:2250 kg·hm^(-2)+3000 ky·hm^(-2)、SO3:3000 kg·hm^(-2)+3000 kg·hm^(-2)),探究不同有机肥及石灰配施量对镉(Cd)污染土壤的修复效果,并采用灰色关联法(Grey relational analysis,GRA)对其修复效益进行综合性评价。结果表明:石灰和有机肥均能有效提高土壤pH,且土壤pH随着石灰配施量的增加而增加,其中SO3处理下pH较CK提高了14.9%。与CK相比,各处理中土壤残渣态镉含量增加,可交换态镉含量降低;且随着石灰施用量的增加,残渣态镉含量呈递增趋势,可交换态镉含量呈递减趋势。SO3处理下小白菜地上部生物量最高,与CK相比提高了87.9%。与CK相比,石灰与有机肥均能降低小白菜中镉的含量,降低效果为SO3>SO2>SO1>FT>OF。基于灰色关联法对土壤-植物系统综合效益进行分析可知:石灰和有机肥配施量均为3000 kg·hm^(-2)的SO3处理的灰色关联度最大,土壤修复效果最佳。

In this study,a soil-based pot experiment was conducted with the combined application of lime and organic matter to explore a suitable way to alleviate soil damage caused by long-term lime application.There were six treatments including control(CK),organic fertilizer(OF:3000 kg·hm^(-2)),lime(FT:1500 kg·hm^(-2)),and the combined application of lime and organic fertilizer at three application ratios:SO1(l 500 kg·hm^(-2)+3000 kg·hm^(-2)),SO2(2250 kg·hm^(-2)+3000 kg·hm^(-2)),and SO3(3000 kg·hm^(-2)+3000 kg·hm^(-2)).Grey relational analysis(GRA)was used to comprehensively evaluate the effect of different treatments on soil-plant systems to select the most suitable application ratio.The results showed that soil pH increased with increasing lime addition rate,and compared with CK,SO3 increased the pH by 14.9%,indicating that the combination of lime and organic matter improved soil pH.Soil residual Cd content increased and soil exchangeable Cd content decreased in all treatments compared with those in CK.With an increase in lime application rate,the proportion of residual Cd increased and exchangeable Cd decreased.SO3 had the highest shoot biomass,and the shoot of pakchoi under SO3 treatment increased by 87.9%compared with that under CK.Compared with CK,both lime and organic fertilizer reduced the content of Cd in pakchoi,and the reduction effect in different treatments was SO3>SO2>SO1>FT>OF.Based on GRA,the data showed that SO3 was the most suitable path for soil remediation,with the highest grey relational degree.