Improvement effects of biochar combined with Robinia pseudoacacia on salinized soil of Tailings in a mining area

LU Rihui; LI Ke; SHENG Shihong; ZHOU Xiaoxing; FU Min; CHEN Chuan; LI Hui

Abstract：Due to its high alkalinity and low nutrient content,the tailing soil in the mining area are not conducive to the growth of plants and may even cause environmental pollution in severe cases.The impact of biochar and Robinia pseudoacacia on the tailing soil in mining areas was studied to provide a theoretical foundation for saline-alkaline improvement,and improve soil environment,and increase land productivity.Pot experiments were conducted,and four treatments were established according to different biochar application amounts,namely CK(no biochar ap-plied,control group),BC1(1％biochar applied),BC3(3％biochar applied),and BC5(5％biochar applied).The physical and chemical properties of the soil and the changes in survival rate,growth(seeding heigh and ground diame-ter),biomass,and root morphology of R.pseudoacacia were assessed.Results indicated that the seedling height,root length,and biomass of R.pseudoacacia reached their maximum values when the biochar addition amount was 5％.The soil pH of BC1,BC3,and BC5 significantly decreased(1.41％-7.51％)compared with CK,suggesting that bio-char can effectively reduce soil alkalinity through neutralization.The electrical conductivity increased with the rise in biochar application amount,especially with 5％biochar,which had the most significant effect,increasing the conductiv-ity content by 181.75％.Simultaneously,both the soil organic carbon content and available phosphorus content in-creased,the BC5 group increased by 42.25％and 111.67％respectively compared with CK,indicating that biochar en-hanced the content of soil nutrient elements,improved soil fertility,and was beneficial in alleviating soil impoverish-ment.The available potassium content in the soil showed a downward trend,the BC5 group decreased by 26.39％com-pared with CK,indicating that nutrient element exchange in the soil occurred.A comprehensive analysis showed that applying 5％biochar can better promote the growth of R.pseudoacacia,reduce soil pH,and improve soil fertility,there-by achieving the effects of waste resource utilization and soil improvement.This entire study and its findings were inte-grated into a single comprehensive paragraph as requested.