外源底物输入对滨海盐渍土有机碳矿化的影响

打开文本图片集

Abstract：Coastal salinesoils serveascriticalreserve landresources withsignificantcarbon sequestration potential.Soil organiccarbon （SOC）mineralization is a primary processdriving soil carbon emisions， whileexogenous substrate inputs regulateSOCdynamicsbyaltering soil microbialgrowthand metabolicactivities.However，theeffectsofthese inputson SOCmineralization incoastal saline soilsremain porlyunderstood.This study examines three salinesoilswith distinct salinity levels in the Yellow River Delta，applying six treatments ∵ light saline soil + straw （SL），moderate saline soil + straw （SM），heavy saline soil + straw （SH）， light saline soil + straw + ammonium nitrate （SNL），moderate saline soil + straw + ammonium nitrate （SNM），and heavy saline soil + straw + ammonium nitrate （SNH）.The influence of exogenous substrate inputsonorganiccarbonmineralizationincoastalsalinesoils is investigated.Themainresearchresultsareasfollows：Straw addition increases SOC to varying degrees.In the treatment of straw combinedwith ammonium nitrate，SOC content declines significantly during incubation， with SNL， SNM， and SNH decreases by 20.48% 29.16% ，and 27.35% ，respectively. The combinedapplicationof strawand ammonium nitrate significantly increases soilrespirationratecompared to straw applicationalone，with the most pronouncedenhancementobserved inheavysalinesoil.Notably，therespiratoryrate in heavysaline soil surpasses thoseoflightand moderatesaline soils during the later stages of incubation.Among the three typesofcoastal saline soils，thecombined applicationconsistently produces the most significant inereases insoil enzyme activity，therebyacceleratingcarboncyclinginsalinesoils.Whilestrawinputenhancesorganiccarboncontentincoastal saline soils tovarying degres，thecombined applicationof straw and ammonium nitrate accelerate organic carbon mineralization through increasedrespirationratesandenzymeactivities.This leads toadecrease inorganiccarboncontent during the incubation period，with this phenomenon being particularly evident in heavy saline soils.

Keywords：Soil salinization; carbon cycle; soil respiration; soil extracellular enzyme activity

土壤盐渍化问题已成为当前农业和生态环境领域亟需解决的关键问题之一。（剩余14560字）