草业学报2025，Vol.34Issue(2)：221-232,12.DOI:10.11686/cyxb2024146
氮添加对黄土丘陵区草地土壤微生物养分限制特征的影响
Effects of nitrogen addition on soil microbial nutrient limitation characteristics in grassland in the Loess Hilly Region
摘要
Abstract
Increasing atmospheric nitrogen deposition is affecting the soil nutrient balance.This may result in decreased nutrient availability to soil microbes.However,the effect of nitrogen deposition on the characteristics of nutrient limitation for soil microbes in grassland in the Loess Hilly Region is still unclear.The objective of this study was to investigate the effects of nitrogen deposition on soil microbial nutrient limitation in this region.A field-based controlled experiment simulating nitrogen deposition was conducted,and the soil microbial biomass,nutrient-transforming enzyme activities,and soil physicochemical properties were determined.This allowed us to elucidate the characteristics of nutrient limitation for grassland soil microorganisms,and its influencing factors,under different nitrogen addition levels.The results showed that nitrogen addition led to a decrease in soil pH,and altered the soil nutrient balance.More specifically,nitrogen addition increased the soil organic carbon and total nitrogen contents,but did not significantly affect the total phosphorus content.In addition,nitrogen addition enhanced the contents of soil available nutrients,with a greater increase in the available phosphorus content than in the soluble carbon and mineral nitrogen contents.This resulted in a relative shortage of carbon and nitrogen as available nutrients.Notably,the soil microbial biomass and extracellular enzyme activities decreased under low nitrogen addition but increased under high nitrogen addition.Further analyses using an enzyme stoichiometric model indicated that with increasing amounts of nitrogen addition,nitrogen limitation for soil microorganisms was intensified,while carbon limitation was alleviated.Microbial carbon limitation also affected the microbial carbon utilization efficiency.The imbalance of soil total and available nutrients caused by nitrogen addition jointly affected the characteristics of nutrient limitation for soil microorganisms by regulating microbial biomass and enzyme activity.In conclusion,these findings provide new information about the characteristics of soil nutrient cycling in grassland as affected by increasing nitrogen deposition.关键词
氮沉降/草地/养分限制/胞外酶活性/养分利用效率Key words
nitrogen deposition/grassland/nutrient limitation/extracellular enzyme activity/nutrient use efficiency引用本文复制引用
贾蕴欢,胡雯颖,邓健,赵雪,陈子玥,王亚楠,李江文,张晓曦..氮添加对黄土丘陵区草地土壤微生物养分限制特征的影响[J].草业学报,2025,34(2):221-232,12.基金项目
陕西省自然科学基础研究计划项目(2024JC-YBMS-224),延安市科技计划项目(2023-CYL-120),榆林市科技计划项目(2023-CXY-212)和国家级大学生创新创业训练计划项目(202310719001)资助. （2024JC-YBMS-224）
