不同比例钾锌共存对土壤镉有效性的影响  

Effect of coexistence of potassium and zinc at different ratios on the cadmium bioavailability in lateritic red soil

作　　者：宋正国[1,2] 徐明岗[2] 刘平[2] 孙楠[2] 唐世荣[1] 

机构地区：[1]农业部环境保护科研监测所//农业部产地环境与农产品安全重点开放实验室,天津300191 [2]中国农业科学院农业资源与农业区划研究所//农业部作物营养与施肥重点开放实验室,北京100081

出　　处：《生态环境学报》2009年第3期904-908,共5页Ecology and Environmental Sciences

基　　金：国家重点基础研究发展规划(973)项目(2002CB410809);北京市自然科学基金项目(6062026);天津市应用基础及前沿技术研究计划(09JCYBJC08500)

摘　　要：单一施用钾或锌肥会改变污染土壤中镉的有效性,但钾与锌共存对镉在土壤-植物系统中迁移和转化影响效果尚待明确。采用盆栽试验,研究了赤红壤上2种镉污染水平下,施用不同比例钾、锌对小油菜(Brassica campetris Lvar.Conmuni)生物量、镉吸收量及土壤溶液中镉质量浓度的影响。结果表明,钾、锌以不同比例与镉共存时并不会对赤红壤上小油菜的生长产生明显影响;增加共存体系中锌的用量,土壤溶液中镉的质量浓度明显升高,而小油菜植株镉含量明显降低。低、高镉污染赤红壤上,钾、锌共存摩尔比例为4∶1时,土壤溶液中镉的质量浓度较对照分别增加189%和159%(两季平均值);小油菜体内镉含量较对照平均分别降低26.0%和34.9%。在低镉污染赤红壤上,钾、锌施用量与小油菜体内镉含量呈显著负相关;高镉污染赤红壤上,锌施用量与土壤溶液中镉的质量浓度呈显著正相关。中轻度镉污染土壤上,小油菜钾、锌肥最佳施用比例为4∶1。钾、锌以不同比例施入土壤时,锌施用量多少是控制土壤镉有效性高低的主要因素.The bioavailability of cadmium could be changed by application of single potassium or zinc into contaminated soil, but the effects of co-existence of potassium and zinc on cadmium migrating in the soil-plant system need to be clarified further. Pot experiments were conducted in the lateritic red soil with two levels of Cd contamination to investigate the effect of K/Zn applications at different ratios on the biomass, amounts of Cd uptake of rape, as well as Zn, K and Cd concentrations in lateritic red soil solutions. The results showed that the coexistence of K and Zn at different ratios did not exert significant effect on the rape growth. Increasing Zn ratio in the K/Zn application resulted in the elevated levels of Zn and Cd in soil solutions, while Cd concentrations in the rape decreased. In lateritic red soil with higher concentration of Cd, the K concentration in the soil solution increased with increasing K content in the K/Zn application. When the molar ratio of K/Zn was 4 ： 1, compared with the control treatment, average Cd content in the rapes decreased by 26.0% and 34.9%, respectively in soils with low and high Cd levels, and Cd concentration in soil solution increased by 189% and 159%, respectively. Applied Zn and K amount was negatively correlated with Cd concentrations in rapes in soil with low Cd levels, whereas in soils with higher Cd levels, applied Zn amount was positively correlated to the Cd concentrations in soil solutions. In lateritic red soil with low or middle Cd levels, the best ratio of coexistence of potassium and zinc was 4 ： 1 when rape fertilized with potassium and zinc fertilizers. It demonstrated that the amount of zinc applied to soils was the major factor to control bioavailability of Cd when K and Zn were simultaneously applied to soils in various ratios.

关 键 词：镉 钾锌共存 小油菜(Brassica Campetris Lvar Conmuni) 赤红壤 有效性 

分 类 号：X131.3[环境科学与工程—环境科学]