Experimental study on soil amelioration of attapulgite clay tailings using microbial agents and maize straw
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.
万方数据
维普
