Effects of Different Biochar Application Rates on Soil Quality and Maize Growth in Salinized Fluvo-aquic Soil

Sun Weijiao; Huang Xiaoyu; Wei Wenliang; Liu Shutang

doi:10.14083/j.issn.1001-4942.2025.03.016

Abstract：Biochar application is one of the important ways to improve soil quality,enhance soil produc-tivity and increase crop yield.In order to clarify the effects of different biochar application rates on soil nutrient content,microbial community structure and maize growth,and analyze the key soil factors affecting the in-crease of maize biomass,the pot experiment was conducted using the salinized fluvo-aquic soil.Four biochar treatments were designed on the basis of conventional application of nitrogen(N),phosphorus(P)and potas-sium(K)fertilizer:no biochar(B0),1％biochar(B1),3％biochar(B3)and 5％biochar(B5).The re-sults showed that soil organic carbon(SOC)content was significantly increased by biochar application com-pared to B0,and increased with the increase of biochar application rate with an average increase amplitude of 284.02％(91.79％～431.99％).Biochar application could significantly increase soil total nitrogen,alkali-hy-drolyzed nitrogen,available phosphorus and available potassium contents,pH value,bacterial richness,bac-terial diversity,fungal richness and fungal diversity,and the average increase amplitude of the 3 biochar treat-ments were 102.25％,31.81％,33.32％,63.89％,3.89％,60.07％,12.21％,96.13％and 22.42％,respec-tively.Meanwhile,maize plant height,stem diameter,leaf area,SPAD value,biomass and NPK absorption a-mount at seedling stage were significantly increased.Correlation analysis results showed that the increase of maize biomass was mainly due to the regulation of SOC,total nitrogen,alkali-hydrolyzed nitrogen,available phosphorus,available potassium,pH,bacterial and fungal richness,and fungal diversity.Overall,biochar application could significantly increase SOC,improve soil nutrient supply and microbial community structure,and so promote maize growth compared to B0 treatment,although there were differences in regulation effects of different biochar application rates on soil quality and maize growth.These results could provide theoretical sup-ports for biochar application strategy,quality improvement and productivity enhancement of salinized fluvo-aquic soil.