施磷水平对再生水灌溉小白菜Cd质量分数和土壤Cd活性的影响

为阐明施用磷肥水平对再生水灌溉下小白菜吸收Cd的影响,以清水为对照,研究了3种施磷水平(80、110、140mg/kg)对3种再生水灌溉方式(清水再生水混灌、清水再生水轮灌、全再生水)下小白菜生物量和Cd质量分数以及土壤活性Cd质量分数的影响。结果表明,全再生水灌溉显著增加小白菜生物量,也显著增加小白菜地上部Cd质量分数,在3个磷处理下Cd质量分数分别增加了54.4%、51.5%、31.7%。高量施磷(110、140mg/kg)显著降低了小白菜地上部Cd质量分数,和施磷80mg/kg处理相比分别降低了16.5%、33.8%。随着施磷水平的提高,土壤活性Cd质量分数降低,施磷140mg/kg处理下降低最为显著,和施磷80mg/kg相比,在3种再生水灌溉方式下分别降低13.5%、16.3%、15.1%。磷肥适量施用能减少再生水灌溉下小白菜对重金属Cd的吸收,有利于保障食品安全。

Effect of Phosphorus Levels on Green Vegetable Cd Concentration and Soil Available Cd Concentration under Reclaimed Wastewater Irrigation

Green house pot culture was adopted to study the effect of three phosphorus levels(P-80、P-110、P-140) on green vegetable Cd concentration and soil available Cd concentration under reclaimed wastewater irrigation.Reclaimed wastewater irrigation increased significantly,in comparison to control,the green vegetables biomass and Cd concentration,and Cd concentration increased by 54.4%,51.5%,31.7% at P-80,P-110 and P-140 treatments,respectively.Compared with P-80 treatment,the green vegetables Cd concentration decreased by 16.5%,33.8% at P-110 and P-140 treatments respectively.Soil available Cd concentration at P-140 treatment decreased by 13.5%,16.3%,15.1% under 1/2 reclaimed wastewater,rotation of clean and reclaimed wastewater,total reclaimed wastewater irrigations respectively.Phosphorus-induced less Cd accumulated in green vegetable might be a contributing to the food safety.