摘要
采矿留下的矿山创面存在诸多问题,且凹土尾矿综合利用率低.壤质化改良可提高尾矿资源化利用率,实现生态修复.研究采用盆栽试验对比改良前后凹土尾矿基本理化性质与壤质土养分比率的改变,分析壤质化尾矿对黑麦草生长特性的影响,结合团聚体分析与电镜扫描探究土壤结构变化机理.研究结果显示:微生物菌剂与秸秆的复合作用能够显著降低尾矿的pH值、电导率和体积质量,增加孔隙度与保水性,并改善基质养分比率.其中,有机质、氮、磷、钾质量比分别最高可达 9.7 g/kg、158.2 mg/kg、82.8 mg/kg、224.6 mg/kg;与对照组相比,黑麦草的发芽率增加10.0百分点、株高增加56.7％,根长增加55.0％.改良壤质尾矿中的大团聚体含量比对照组提高了14.3％,微观状态下观察到形成了稳定的团聚体结构与覆盖层.
Abstract
The mining activities have left significant challenges,resulting in numerous issues related to mine waste.Additionally,the comprehensive utilization rate of concave soil tailings remains low.Loamification can enhance the resource utilization of these tailings,thereby facilitating ecological restoration.The combined application of microbial agents and corn straw significantly improved the physicochemical properties of concave kaolin tailings compared to their individual use.This approach reduced bulk density,pH,and electrical conductivity,while simultaneously increasing moisture content,permeability coefficient,and total porosity,thereby promoting natural restoration.The combined use of microbial agents and straw can maximize the mass ratios of organic matter,available nitrogen,available phosphorus,and available potassium in tailings to 9.7 g/kg,158.2 mg/kg,82.8 mg/kg,and 224.6 mg/kg,respectively.This approach also optimizes the carbon,nitrogen,and phosphorus ratios,enhancing nutrient conditions and promoting microbial decomposition and transformation of organic matter.As a result,it increases fertilizer utilization and soil fertility,leading to improved plant uptake and utilization.The seed germination rate,plant height,and root length of ryegrass grown in amended tailings increased by 10.0 percentage points,56.7％,and 55.0％,respectively,in samples treated with 0.5％microbial agent and 5％straw compared to the control.Additionally,the treatment of 0.5％microbial agent and 2.5％straw exhibited relatively superior growth effects while also enhancing mechanical stability,which is critical for steep slopes.The addition of straw and microbial agents promoted the formation of large water-stable aggregates(＞2 mm)while significantly reducing the presence of micro-aggregates(0-0.25 mm).Microbial agents facilitated the formation of micro-aggregates,whereas straw enhanced the development of large aggregates.When used together,they increased the content of large aggregates by 14.3％.Micrographs of the amended samples revealed an improved particle structure characterized by increased porosity and a looser texture,likely due to the organic coatings formed on particle surfaces by the additives.These findings will aid in utilizing industrial waste for soilless greening,enhancing plant stability in mine-affected areas.Additionally,the study provides a recommended proportion of microbial agents and straw to minimize resource loss and improve the efficiency of ecological restoration.
基金项目
中国博士后科学基金资助项目(2021M703507)
江苏省大学生创新训练项目(202310292356B)
江苏省产学研合作资助项目(BY2021208)
维普
万方数据