Abstract: To investigate the relationship between plant and soil nutrients with inter-month variation under nitrogen addition. Five levels of 0 (N0),15 g·Nm^-2 (N1),30 g·Nm^-2 (N2),45 g·Nm^-2 (N3) and 60 g·Nm^-2 (N4) were used to determine ammonium nitrogen,nitrate nitrogen,available nitrogen,organic carbon,total nitrogen,total potassium,and total phosphorus in soil and plants. The results showed that the above-ground total potassium content,root total phosphorus,and soil organic carbon content of the plants tended to increase with inter-month variation under nitrogen addition;the nitrate and available nitrogen content of the roots and the available nitrogen content of the soil tended to increase and then decrease;the total nitrogen content of the roots and the ammonium and total nitrogen content of the soil tended to decrease and then increase;the available nitrogen,total nitrogen content of the above-ground parts of the plants,the ammonium nitrogen and organic carbon content of the roots and organic carbon content in the root system tended to decrease. There was a significant positive and negative correlation between plant and soil nutrients (P<0.05),but the pattern of inter-month variation was not consistent. These results suggest that plant nutrient use strategies and soil nutrient availability under nitrogen addition are influenced by inter-month variation and that the correlation between plant and soil nutrients varies between months.

Key words: Nitrogen addition, Inter-monthly variation, Nutrients, Correlation

摘要： 为了探究氮素添加下植物及土壤养分随月际变化的关系。本研究以玉树州称多县高寒草甸为研究对象，设置0(N0)，15 g·Nm^-2(N1)，30 g·Nm^-2(N2)，45 g·N m^-2(N3)，60 g·Nm^-2(N4)5个氮素添加水平，测定土壤及植物中铵态氮、硝态氮、速效氮、有机碳、全氮、全钾、全磷等指标。结果表明：在氮素添加下随月际变化植物地上部分全钾含量、根系全磷、土壤有机碳含量呈增加的趋势；根系硝态氮、速效氮含量，土壤速效氮含量呈先增加后降低的趋势；根系全氮含量，土壤铵态氮、全氮含量呈先降低后增加的趋势；植物地上部分速效氮和全氮含量、根系铵态氮和有机碳含量呈降低的趋势。植物与土壤养分间存在显著正相关及负相关性(P<0.05)，但随月际变化规律并不一致。以上结果说明氮素添加下植物养分利用策略及土壤养分供给能力会受到月际变化的影响，且在不同月份变化下植物及土壤养分间的关联性是不同的。

关键词: 氮素添加, 月际变化, 养分, 相关性