生物炭、沸石与膨润土混施对玉米生长和吸收Cd、Pb、Zn的影响研究

Influence of Fixed Addition of Biochar, Zeolite and Bentonite on Growth and Cd, Pb, Zn Uptake by Maize

矿区周边农田土壤重金属污染严重威胁着粮食安全,利用原位钝化修复技术,在农业生产的同时进行重金属污染农田土壤治理,收获符合卫生标准的农产品,具有重要的现实意义。选取生物炭、沸石粉和膨润土3种钝化剂开展田间试验,研究不同用量钝化剂单施及混施对玉米(Zea mays L.)生长、玉米籽粒吸收Cd、Pb、Zn与土壤有效态Cd、Pb、Zn等的影响,旨在为Cd-Zn复合污染农田安全生产和阻控提供数据支持。结果表明:单施及混施不同用量钝化剂均能促进玉米株高、叶面积和生物量增加,显著提高玉米产量(P<0.05),钝化剂处理较对照CK增产3.41%-31.69%。不同钝化剂处理可提高土壤pH值和有机质含量,明显降低土壤中的有效态Cd、Pb、Zn含量,与CK相比,单施及混施不同用量钝化剂导致土壤有效态Cd、Pb、Zn分别降低23.02%-45.24%、4.86%-21.46%、16.38%-32.60%,其中5%SFP(5%生物炭+5%沸石粉+5%膨润土)处理降低效果最显著,2%SFP处理次之;单施及混施不同用量钝化剂都能降低玉米籽粒对Cd、Pb、Zn的吸收,其中5%SFP处理能明显降低玉米籽粒中Cd、Pb、Zn含量,较CK分别降低68.18%,39.49%,31.83%。综合表明,在原位钝化修复Cd-Zn复合污染农田土壤时,钝化剂混合施用的效果好于单施,以5%SFP混合施用的效果最佳。

Heavy metal pollution of agricultural soil around mine areas is threatening food security seriously.It has important practical implications to remediate soils contaminated with heavy metals and harvest agricultural products met hygineic criterion at the same time in situ passivation and repair technique.Field experiments were conducted with biochar,zeolite and bentonite to investigate the effect of singled and mixed application of different amendments on maize growth and cadmium(Cd),lead(Pb)and zinc(Zn)uptake by maize kernels and the contents of available Cd,Pb and Zn in soil,so as to provide statistic data for safe agricultural production on Cd-Zn composite polluted farmland.The results showed that singled and mixed application of amendments could increase plant height,leaf area as well as biomass.The yield of maize was also significantly increased(P<0.05).Compared to the control treatment,all amendments treatment increased the yield of maize by 3.41%-31.69%.Different amendments treatment could increase soil pH values and organic matter content,and significantly reduce the contents of available Cd,Pb and Zn in soil.Compared to the control treatment,singled and mixed applying different amendments led to a decrease of available Cd content in soil by 23.02%-45.24%,available Pb by 4.86%-21.46%,and available Zn by 16.38%-32.60%.Additions of 5%SFP(5%biochar+5%zeolite+5%bentonite)was the most available treatments to decrease the available content of heavy metals in soil,and 2%SFP(2%biochar+2%zeolite+2%bentonite)was ranked to be the second.At the same time,singled and mixed applying of different amendments could all reduce Cd,Pb and Zn uptake by maize kernels.Compared to the control treatment,the application of 5%SFP reduced the content of Cd,Pb and Zn in maize kernels by 68.18%,39.49%and 31.83%respectively.The results in this study demonstrat that the effect of mixed application is better than that of singled application,and the 5%SFP mixed application is the best functional amendments for the remediation of heavy metal contaminated soil of Cd-Zn.