摘要
【目的】探讨施用不同肥料条件下,巨菌草对镉(Cd)污染农田土壤的野外实际修复效果。【方法】以矿区周边Cd污染农田土壤为对象进行田间试验,设置对照(CK)、氯化铵(NH_(4)Cl)、氯化钾(KCl)、尿素[CO(NH_(2))_(2)]等4个处理,肥料用量为0.6 kg·m^(−2),分析不同处理下巨菌草对土壤Cd吸收富集的影响。【结果】NH_(4)Cl和KCl处理均能显著增加巨菌草叶片Cd含量(P<0.05),而CO(NH_(2))_(2)处理对巨菌草Cd含量的影响不显著。巨菌草生长150 d时,NH_(4)Cl、CO(NH_(2))_(2)和KCl处理均显著提高巨菌草地上部的生物量(P<0.05);对照处理下,巨菌草地上部Cd提取量为6.52 mg·株^(−1),NH_(4)Cl、CO(NH_(2))_(2)和KCl处理使地上部Cd提取量分别增加了70.19%、43.58%和59.05%,NH_(4)Cl处理显著提高巨菌草对Cd的迁移系数和生物富集系数。NH_(4)Cl、CO(NH_(2))_(2)和KCl处理均提高了巨菌草对Cd提取速率,缩短对Cd污染土壤的修复年限。以150 d作为收获周期(一年收获2茬),NH_(4)Cl处理使土壤Cd含量降低至国家农用地土壤污染风险筛选值(pH≤5.5,Cd≤0.3 mg·kg^(−1))所需的理论修复时间最短,为9.07年。此外,巨菌草在90~150 d期间对Cd的平均提取速率是1~90 d生长期间的1.13~2.58倍。【结论】建议以150 d作为收获周期(一年收获2茬),NH_(4)Cl可作为巨菌草提取土壤Cd的强化剂。
【Objective】Enhancing effect of chemical fertilizers on the phytoextraction of king grass(Pennisetum sinese Roxb)on cadmium(Cd)in contaminated soil were evaluated.【Method】Chemical fertilizers,i.e.,NH_(4)Cl,KCl,and CO(NH_(2))_(2),at the rate of 0.6 kg·m^(−2) were applied,along with control,to the soil nearby a cadmium-contaminated mining field for the experimentation.【Result】The fertilizations significantly increased the aboveground biomass of the king grass in 150 d(P<0.05).The addition of NH_(4)Cl or KCl raised the Cd concentration in the grass leaves(P<0.05),but CO(NH_(2))_(2) showed no significant effect.Comparing with control,which had a Cd-accumulation in grass leaves of 6.52 mg·plant^(−1),NH_(4)Cl increased the accumulation by 70.19%,CO(NH_(2))_(2) by 43.58%,and KCl by 59.05%.The NH_(4)Cl addition significantly rose the coefficients of Cd transfer from land and bioconcentration in grass.Significantly,these fertilizers improved the efficiency of Cd removal from soil by king grass reducing the time for the pollution remediation.The Cd-removal in 90-150 d was 1.13-2.58 times greater than that in 1-90 d.It was estimated that a 150 d harvest cycle and twice a year on king grass planted in the Cd-contaminated field fertilized with NH_(4)Cl could turn the soil to meet the minimum national safety requirements of pH≤5.5 and Cd≤0.3 mg·kg^(−1) in 9.07 years.【Conclusion】It was recommended twice a year of 150 d harvest cycle with NH_(4)Clfertilization be applied on the Cd-contaminated soil to mitigate the pollution in soil.
作者
罗泉达
LUO Quanda(Agricultural Ecology Environment and Resource Station of Fujian,Fuzhou,Fujian 350003,China)
出处
《福建农业学报》
CAS
CSCD
北大核心
2022年第3期398-404,共7页
Fujian Journal of Agricultural Sciences
基金
福建省蔬菜产业重大农技推广服务试点项目(KNJ152025)。
关键词
巨菌草
镉
肥料
田间试验
提取速率
King grass(Pennisetum sinese Roxb)
cadmium
fertilizer
field experimentation
removal efficiency
