三种改良剂对土壤中镉(Cd)的钝化及小白菜品质的影响

Effects of three amendments on passivation of cadmium(Cd) in soil and quality of Chinese cabbage

以白云石煅烧物、腐植酸、山梨糖醇及尿素等原料按照一定比例配制土壤改良剂,并设置3种改良剂处理(T1.5、T3.0、T4.5)和1个对照(T0),探究3种改良剂对镉(Cd)的钝化效果以及小白菜品质的影响。结果表明,3种改良剂能显著提高土壤pH并降低土壤有效态Cd含量,土壤pH从T0的5.75提升到T4.5的7.28,土壤有效态Cd含量比T0处理分别降低18.5%、29.7%、30.2%;3种改良剂能促进小白菜生长,与T0处理相比,地上部鲜重分别提高5.5%、7.9%、12.9%,也降低了小白菜地上部Cd含量,分别降低了15.0%、34.5%、36.9%,Cd含量远低于《食品安全国家标准食品中污染物限量》(GB2762—2017);施用改良剂在一定程度上提高了小白菜地上部的品质,与T0处理相比,T3.0和T4.5处理显著降低了可滴定酸含量,T1.5、T3.0和T4.5处理显著提高了维生素C含量。综合分析表明,3种改良剂对土壤中Cd具有显著的钝化效果,而且保障了小白菜中Cd含量达到安全水平,同时也提高了小白菜的品质。本研究结果为Cd污染土壤治理提供了理论依据。

Soil conditioners were formulated with dolomite calcine,humic acid,sorbitol and urea in certain proportions,and three conditioner treatments(T1.5,T3.0,T4.5)and one control(T0)were set to investigate the effects of the three conditioners on the passivation of cadmium(Cd)and the quality of Chinese cabbage.The results showed that the three amendments significantly increased soil pH and reduced soil effective state Cd content,soil pH increased from 5.75 in T0 to 7.28 in T4.5,and soil effective state Cd content decreased by 18.5%,29.7%and 30.2%,respectively,compared with T0 treatment;the three amendments promoted the growth of Chinese cabbage,and compared with T0 treatment,above-ground fresh weight increased by 5.5%,7.9%and 12.9%,respectively.The Cd content in the aboveground parts of Chinese cabbage was reduced,by 15.0%,34.5%and 36.9%,respectively,with Cd content much lower than the National Standard for Food Safety Limits of Contaminants in Food(GB2762-2017);the application of improvers improved the quality of aboveground parts of Chinese cabbage to some extent.Compared with the T0 treatment,the T3.0 and T4.5 treatments significantly reduced the titratable acid content,and the T1.5,T3.0 and T4.5 treatments significantly increased the vitamin C content.The comprehensive analysis showed that the three amendments had a significant blunting effect on Cd in the soil,guaranteed a safe level of Cd content in Chinese cabbage,and also improved the quality of Chinese cabbage.The results of this study provide a theoretical basis for the management of Cd-contaminated soils.