土壤学报2025，Vol.62Issue(3)：811-824,14.DOI:10.11766/trxb202403220128
不同盐渍化土壤养分-微生物生物量-胞外酶活的化学计量特征
Stoichiometric Characteristics of Nutrient-Microbial Biomass-Extracellular Enzyme Activity in Different Salt-affected Soils
摘要
Abstract
[Objective]Soil salinization restricts the improvement of nutrient utilization efficiency and productivity enhancement.Studying the dynamics of soil nutrient changes and microbial feedback under saline stress can provide a scientific basis for nutrient management in salt-affected soils.[Method]Soils with salinity ranging from<3 g·kg-1(S1),3-10 g·kg-1(S2),and>10 g·kg-1(S3)of typical soil salinization areas in China were collected.By analyzing the differences in carbon,nitrogen,and phosphorus contents,microbial biomass,extracellular enzyme activity and their ecological stoichiometric ratios,this study aimed to clarify the changing trend of soil nutrients and microbial metabolism limitation characteristics under different salinity barriers.[Result]The results of the study showed that:(1)Organic carbon,total nitrogen,total phosphorus,alkaline dissolved nitrogen,and available phosphorus contents of the salt-affected soils all decreased.According to the nutrient grading standards of the Second National Soil Census,the organic carbon,total nitrogen,and alkaline dissolved nitrogen of S3 all dropped to the fifth level(deficiency),while soil phosphorus and potassium pools were all relatively sufficient.(2)The ratio of extracellular carbon-acquiring enzyme activity to extracellular nitrogen-acquiring enzyme activity(Enzyme C/N),the ratio of extracellular carbon-acquiring enzyme activity to extracellular phosphorus-acquiring enzyme activity(Enzyme C/P)and the ratio of extracellular nitrogen-acquiring enzyme activity to extracellular phosphorus-acquiring enzyme activity(Enzyme N/P)of different salt-affected soils all deviated from 1︰1 to different degrees.Also,the results of vector characteristics of extracellular enzyme stoichiometry showed that microbial carbon limitation and microbial nitrogen limitation in S3 were significantly higher than those in S1 and S2.This phenomenon indicates that increased salinization caused soil elements and microbial metabolic activity to gravitate towards carbon and nitrogen resource limitation.(3)The salt content(TS),Na+,K+,exchangeable sodium percentage(ESP),Cl-and annual average evaporation-precipitation ratio(MAV/MAP)were the key constraints on changes in the carbon,nitrogen,and phosphorus stoichiometric ratios of soil nutrients,microbial biomass,and extracellular enzyme activities in salt-affected soils.The results of the random forest model showed that Cl-,TS,and MAV/MAP were the main drivers of microbial relative carbon limitation.TS,ESP,sodium adsorption ratio(SAR),Cl-,Na+and MAV/MAP were the main drivers of microbial relative nitrogen limitation.[Conclusion]In summary,compared to the relatively sufficient status of phosphorus and potassium nutrient pools,salinity stress tends to induce a co-limitation of carbon and nitrogen in both soil and microbial communities,the severity of which escalates with the intensification of salinization.Therefore,there is an urgent need to put forward methods of organic regulation and efficient carbon and nitrogen management for salt-affected arable soils.关键词
盐渍化土壤/土壤养分/生态化学计量特征/土壤微生物生物量/土壤胞外酶活性/资源限制Key words
Salt-affected soils/Soil nutrient/Ecological stoichiometric characteristics/Soil microbial biomass/Soil extracellular enzyme activity/Resource constraints分类
农业科技引用本文复制引用
陈玉琪,徐灵颖,王志旺,王相平,姚荣江,赵旭..不同盐渍化土壤养分-微生物生物量-胞外酶活的化学计量特征[J].土壤学报,2025,62(3):811-824,14.基金项目
中国科学院战略性先导科技专项(XDA0440000)资助 Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0440000) （XDA0440000）
