不同钝化产品对水稻生产中镉、铅、砷的钝化效果

Inhibiting effects of immobilization agents on cadmium,lead and arsenic in rice production

采用田间试验,持续2年(2021—2022年)研究了市售6种钝化剂不同施用量(0、2 250、4 500、6 750 kg·hm^(-2))对土壤中镉(Cd)、铅(Pb)、砷(As)有效态含量,土壤pH值,及稻米Cd、Pb、As含量的影响。结果表明,选择适宜用量的钝化剂可显著(P<0.05)提高土壤pH值,降低土壤有效态Cd、Pb、As含量。其中,施用6 750 kg·hm^(-2)长效型钝化剂的效果在2021年最优,土壤pH值由5.00提高至6.98,土壤有效态Cd、Pb含量分别显著降低82.2%和98.6%。此外,长效型钝化剂在4 500 kg·hm^(-2)用量下,第二年的稻米镉含量仍可显著降低90.8%。综上,在对比的6种钝化剂中,长效型钝化剂阻控水稻籽粒Cd富集的效果和持效性最优,推测与其碳酸钙含量较高有关。

In the present study,a field experiment was conducted with different application rates(0,2 250,4 500,6 750 kg·hm~(-2)) of commercial immobilization agents to examine their inhibiting effect on soil available cadmium(Cd),lead(Pb),arsenic(As) contents,soil pH value and Cd,Pb,As contents in rice grains for 2 years(2021—2022).It was shown that application of appropriate rate of immobilization agents significantly(P<0.05) increased soil pH value and decreased soil available Cd,Pb,As contents in soil.Among the 6 immobilization agents,the best effect in 2021 was noted in the treatment of application of 6 750 kg·hm~(-2) long-acting passivator,as the soil pH value was significanlty increased from 5.00 to 6.98,the soil available Cd,Pb contents were significantly decreased by 82.2%,98.6%,respectively.Besides,in 2022,application of 4 550 kg·hm~(-2) long-acting passivator also significantly decreased Cd content in rice grains by 90.8%.In general,the long-acting passivator had the best effect and persistence among all the used immobilization agent,which might be related to its high content of calcium carbonate(CaCO_3).