铁尾矿不同改良措施对苜蓿和紫穗槐生长的影响

Effects of different improvement measures on plant growth of Medicago sativa and Amorpha fruticosain iron tailings

以河北省迁安市铁尾矿为基质,通过苜蓿和紫穗槐盆栽试验,研究铁尾矿与无机肥、土壤、有机肥(猪粪)的不同基质配比在短期内对豆科植物苜蓿和紫穗槐生长的影响,旨在为铁尾矿土壤修复和植被恢复提供依据,结果表明:1%猪粪施肥处理下2种植物出苗率较高,分别为72%和52%,掺土处理效果整体好于施肥处理,当掺土25%时,苜蓿、紫穗槐出苗情况已大有改善,出苗率分别为86%、71%;掺土处理对紫穗槐、苜蓿的叶绿素和蛋白含量影响更显著,当掺土25%以上时,二者叶绿素含量显著增加,直至全土处理达到最大值(36.33mg/g、33.79mg/g);苜蓿在掺土量达到25%、紫穗槐在掺土量达到75%时,植物蛋白含量开始明显提升,分别为4.12%、4.52%;紫穗槐的平均株高(28.82cm)、生物量(9.35g)、根冠比(1.31%)等生长指标均高于苜蓿(15.70cm、8.14g、0.55%);掺土处理对2种植物各生长指标作用显著,其中25%掺土处理就开始有明显提升;1%猪粪促进植物生长;5%以上猪粪施用量抑制植物成活及生长;尾矿中添加土壤比补充肥料更有利于苜蓿、紫穗槐生长,但25%掺土和无机肥混合配比也能促进苜蓿和紫穗槐的生长。

The effects of Qian＇an iron tailings as the matrix improved with different substrate ratio of inorganic fertilizer,soil and organic fertilizer（pig manure）on physical and chemical properties of the iron tailings and plant growth in short term were studied through pot experiments on Medicago sativa and Amorpha fruticosa,in order to provide the basis for soil remediation and vegetation restoration.The main results showed as follows：Seedling emergence of Medicago sativa and Amorpha fruticosa was high at 72% and 52% when treated with 1% of pig manure.The soil-mixed iron tailing was more beneficial to improving seedling emergence than fertilizer-applied iron tailing on the whole.Seedling emergence of Medicago sativa and Amorpha fruticosa was significantly improved by 86% and 71% when iron tailing was mixed with 25% of the mixed soil.The chlorophyll concentration of Medicago sativa and Amorpha fruticosa was significantly increased with the increasing of the soil proportion in iron tailings and improved remarkably at 25% proportion of mixed soil,and even reached the maximum level of 36.33mg/g and 33.79mg/g when the proportion of the mixed soil was 100%.Soil-mixed iron tailings had a remarkable improvement effect on plant protein content of Medicago sativa and Amorpha fruticosa,which increased with mixed soil of25% and 75%,respectively.Growth indexes of Amorpha fruticosa,including plant height（28.82cm）,biomass（9.35g）,and root cap ratio（1.31%）,were higher than those of Medicago sativa（15.70 cm,8.14 g and 0.55%）,indicating soil-mixed iron tailing could most effectively improve growth indexes of the two plants.The iron tailings applied with 1%pig manure could effectively promote plant growth,but it could reduce the plant survival rate and inhibit plant growth when the proportion of applied pig manure was more than 5%,indicating the soil-mixed iron tailing was more beneficial to the plant growth than the fertilizerapplied.In addition,the iron tailing mixed with 25% soil and inorganic fertilizer could also effectively improve the plant growth.