草地学报 ›› 2026, Vol. 34 ›› Issue (6): 2099-2108.DOI: 10.11733/j.issn.1007-0435.2026.06.013

• 研究论文 • 上一篇    

氮磷添加缓解了紫花苜蓿土壤微生物养分限制

祝文知1, 罗珠珠1,2, 李亮亮3, 何仁元4, 刘家鹤1   

  1. 1. 甘肃农业大学资源与环境学院, 甘肃 兰州 730070;
    2. 省部共建干旱生境作物学国家重点实验室, 甘肃 兰州 730070;
    3. 甘肃农业大学草业学院, 甘肃 兰州 730070;
    4. 甘肃农业大学林学院, 甘肃 兰州 730070
  • 收稿日期:2025-11-20 修回日期:2026-01-19 发布日期:2026-06-02
  • 通讯作者: 罗珠珠,E-mail:luozz@gsau.edu.cn
  • 作者简介:祝文知(2000-),女,汉族,甘肃金昌人,硕士研究生,主要从事土壤生态方面的研究,E-mail:2403924052@qq.com
  • 基金资助:
    国家自然科学基金项目(32560778,31860364);甘肃省优秀研究生“创新之星”项目(2025CXZX-814)资助

Nitrogen and Phosphorus Addition Alleviated Soil Microbial Nutrient Limitation in Alfalfa Fields

ZHU Wen-zhi1, LUO Zhu-zhu1,2, LI Liang-liang3, HE Ren-yuan4, LIU Jia-he1   

  1. 1. College of Resources and Environment, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China;
    2. State Key Laboratory of Arid Habitat Crop Science, Lanzhou, Gansu Province 730070, China;
    3. College of Pratacultural Science, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China;
    4. College of Forestry, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China
  • Received:2025-11-20 Revised:2026-01-19 Published:2026-06-02

摘要: 本研究以黄土丘陵区紫花苜蓿地为研究对象,设置不施肥(CK)、单施氮肥(T1)、单施磷肥(T2)和氮磷肥配施(T3)4个处理,通过分析氮磷添加下紫花苜蓿土壤-微生物-胞外酶生态化学计量特征,探讨土壤养分限制特征及微生物对代谢限制的反馈机制。结果表明,施肥降低了土壤碳磷比、微生物量碳磷比(MBC∶MBP)、微生物量氮磷比(MBN∶MBP)和酶化学计量碳氮比(EEAC∶N),但增加了土壤养分含量、微生物量、胞外酶活性和酶化学计量氮磷比(EEAN∶P)。酶向量模型和矢量分析结果表明,长期种植苜蓿土壤微生物受到不同程度的碳限制和磷限制,氮磷添加缓解了土壤微生物磷限制,提高了微生物碳利用效率(CUE)。综上,黄土丘陵区长期种植苜蓿土壤应适当补施氮磷肥,以缓解土壤微生物的养分限制。

关键词: 黄土丘陵, 胞外酶, 微生物养分限制, 碳利用效率

Abstract: This study focued on alfalfa fields in the Loess hilly region as research objects, with four experimental treatments were established: no fertilization (CK), nitrogen fertilizer alone (T1), phosphorus fertilizer alone (T2), and combined nitrogen-phosphorus fertilization (T3). By examining the ecological stoichiometry of soil-microbe-extracellular enzyme systems under nitrogen and phosphorus addition, this research explored the characteristics of soil nutrient limitations and the feedback mechanisms of microbial communities to metabolic constraints. The results showed that fertilization significantly decreased soil carbon to phosphorus ratio, microbial biomass carbon to phosphorus ratio (MBC∶MBP), microbial biomass nitrogen to phosphorus ratio (MBN∶MBP), and enzymatic stoichiometric carbon to nitrogen ratio (EEAC∶N). In contrast, soil nutrient content, microbial biomass, extracellular enzyme activities, and enzymatic stoichiometric nitrogen to phosphorus ratio (EEAN∶P) were significantly increased. Enzyme vector modeling and vector analysis indicated that long-term alfalfa cultivation led to varying degrees of carbon and phosphorus limitation in soil microorganisms. Nitrogen and phosphorus addition alleviated the microbial phosphorus limitation and increased microbial carbon use efficiency (CUE). In conclusion, appropriate supplementation of nitrogen and phosphorus fertilizers is recommended for soils under long-term alfalfa cultivation in the Loess hill region, to mitigate nutrient limitations on soil microorganisms.

Key words: Loess hills, Extracellular enzymes, Microbial nutrient limitation, Carbon utilization efficiency

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