间作修复对玉米镉含量影响的整合分析

Effects of intercropping remediation on Cd concentration in maize and its influencing factors with meta-analysis

【目的】分析间作修复对镉(Cd)污染农田玉米Cd含量影响,旨在为实现污染农田边生产边修复提供基础支撑。【方法】本研究以“玉米”、“Cd”、“间作”为关键词,在“中国知网”和“Web of Science”数据库检索2006—2020年期间发表的文献,筛选出符合要求的文献33篇,获得数据770组。以玉米单作为对照,利用整合分析(meta-analysis)方法揭示间作修复对玉米Cd含量影响,明确间作植物种类、玉米品种、土壤性质和栽培措施等因素的综合效应。【结果】与单作玉米相比,大田间作修复能显著降低玉米籽粒、茎叶和根Cd含量,尤其对籽粒Cd抑制作用最显著。蜈蚣草+籽粒苋、蜈蚣草、籽粒苋和龙葵等间作植物对玉米籽粒Cd含量有显著抑制作用;东单、海禾28和绿玉269等玉米品种籽粒Cd含量也显著受间作修复抑制。在弱酸性或中性土壤上,间作修复对玉米籽粒Cd的抑制作用增强;无论是安全利用类还是严格管控类农田,间作修复均能显著降低玉米籽粒Cd含量;间作行距对玉米籽粒和茎叶Cd含量影响不显著,但0~30 cm行距显著降低根Cd含量。盆栽间作修复涉及到的间作植物以及玉米品种较多,Meta分析结果表明,盆栽间作修复对玉米Cd含量降低作用不显著;此外,间作植物鸡眼草、黑麦草和苜蓿,以及主栽作物金珠蜜等间作修复效果在大田或盆栽试验下差异较大。【结论】间作修复可以显著降低玉米Cd含量,提高Cd污染玉米农田修复效率。选用合适的主栽玉米品种和间作修复植物是提高间作修复效果的重要因素;间作行距及土壤pH、Cd含量等因素对修复效果影响还需深入探讨。

【Objectives】Effects and key influencing factors of intercropping remediation on maize Cd concentrations in Cd-contaminated maize farmland were analyzed,in order to provide technical parameters for the farmland soil remediation during production.【Methods】The data were obtained by searching from the published papers in“CNKI”and“Web of Science”database from 2006 to 2020,using“Cd contamination”,“intercropping”,“maize”etc.as the main keywords.According to the requirement of meta-analysis,there were 770 sets of data for Cd concentrations in maize from 33 literatures.The effect value of intercropping was defined as the response ratio of its intercropping over monoculture treatment within a same trial,and metaanalysis method was used to quantitatively analyze the contribution of each factor on remediation response effect.【Results】Compared with monoculture maize,intercropping remediation in field could significantly reduce Cd concentration in maize grain,stem-leaves and root,especially with the highest decrease rates in grain.Centipede grass+Amaranthus paniculatus L.,Centipede grass,Amaranthus paniculatus L.and Solanum nigrum significantly inhibited the concentration of Cd in maize grain.And Cd concentrations in grain of Dongdan,Haihe 28 and Lüyu 269 were decreased significantly under intercropping remediation.Weak acid or neutral soil enhanced the inhibition of intercropping remediation on Cd concentration in maize grain.In both safe utilization and strict control farmland,Cd concentration in maize grain was significantly reduced with intercropping remediation.Row spacing with 0–30 cm significantly reduce Cd concentration in roots,but row spacing had no effects in grain and stem-leaves.However,meta-analysis showed that intercropping remediation had no significant effect on the reduction of Cd concentration in maize,for there were many intercropping plants and maize varieties in intercropping remediation under pot culture conditions.In addition,the effects of intercropping plants such as corngrass,ryegrass and alfalfa,as well as the main crop Jinzhumi,were different in field or pot trails.【Conclusions】Intercropping remediation can significantly inhibit the concentration of Cd in maize and improve the remediation efficiency of Cd-contaminated maize farmland.The selection of suitable maize cultivars and intercropping remediation plants has a significant impact on improving the effect of intercropping remediation.At the same time,the row spacing of maize and intercropping plants,soil pH and Cd concentration before remediation also have a certain impact on the remediation effect of intercropping.The results provide some technical parameters and theoretical basis for the remediation technology of Cd contaminated corn in China.