农业现代化研究2025，Vol.46Issue(4)：789-797,9.DOI:10.13872/j.1000-0275.2025.0191
桂西北喀斯特与非喀斯特森林土壤微生物氮利用效率及残体氮特征
Soil microbial nitrogen use efficiency and residue nitrogen in karst and non-karst forests of Northwest Guangxi,Southwest China
摘要
Abstract
Microbial residue nitrogen(N)is an important component of soil N pool,with its formation and stabilization playing a crucial role in soil N accumulation.Soil microbial N use efficiency(NUE),i.e.,the proportion of total utilized organic N allocated to microbial biomass synthesis,significantly influences microbial residue N accumulation.However,the linkage of soil microbial NUE with microbial N residue remains poorly understood.In this study,soil microbial NUE,microbial N residue,and other soil properties were determined for three mineral soil horizons,i.e.,0～10 cm,10～20 cm,and 20～40 cm in karst and non-karst forests of Northwest Guangxi.Microbial NUE in the karst forest was 0.41±0.05,2.93 times higher than that in the non-karst forest(0.14±0.04).Total microbial residue N in the karst forest was 1.32±0.26 g/kg,2.17 times greater than in non-karst forest(0.61±0.11 g/kg).There was no significant difference in microbial NUE across soil horizons,but total microbial residue N decreased with soil horizon.Microbial NUE was controlled by microbial growth and positively related to the stoichiometric imbalance between soil C:N and microbial biomass C:N.Total microbial residue N was positively related to exchangeable calcium and N-acquisition enzyme activity,but exhibited no significant correlation with microbial NUE.This indicates that exchangeable calcium contributes more dominantly than microbial NUE in promoting microbial residue N accumulation,primarily by protecting it from microbial decomposition through mineral-associated mechanisms.These findings contribute to the understanding of soil microbial N metabolism and N accumulation mechanisms in karst forests.关键词
微生物氮素利用效率/微生物残体氮/微生物生长/矿物保护/氮累积Key words
microbial nitrogen use efficiency/microbial residue nitrogen/microbial growth/mineral protection/nitrogen accumulation分类
农业科技引用本文复制引用
谢心怡,颜晓凤,朱梓弘,贺姣,李德军..桂西北喀斯特与非喀斯特森林土壤微生物氮利用效率及残体氮特征[J].农业现代化研究,2025,46(4):789-797,9.基金项目
国家自然科学基金(U22A20560) （U22A20560）
广西"八桂学者"项目.Supported by National Natural Science foundation of China(U22A20560) （U22A20560）
Guangxi Bagui Scholarship Program. （）
