氮素和水分添加对荒漠草原短花针茅氮磷特征的影响  

Effects of nitrogen and water addition on herbage N and P concentrations of Stipa breviflorain a desert steppe grassland

作　　者：白春利[1,2] 刘永志 王明玖[1] 单玉梅 哈斯呼 

机构地区：[1]内蒙古农业大学生态环境学院,内蒙古呼和浩特010019 [2]内蒙古自治区农牧业科学院,内蒙古呼和浩特010031

出　　处：《草业学报》2016年第3期251-256,共6页Acta Prataculturae Sinica

基　　金：内蒙古科技创新引导奖励资金计划(20140701);国家牧草产业体系(CARS-35-27)项目资助

摘　　要：植物氮(N)、磷(P)含量特征为研究植物的养分利用状况提供了重要的手段。为判断草地生态系统植被限制性元素及对环境的适应策略,在短花针茅荒漠草原的自由放牧区进行了N和水分添加试验,研究在N和水分添加条件下优势植物短花针茅叶的N、P含量及其化学计量特征。通过对N添加、水添加和N水同时添加3个处理的测定表明,短花针茅通过提高叶N含量来增强对贫瘠生境的适应能力。N和水分是影响短花针茅N吸收的限制因子。短花针茅叶N、P含量及N∶P对N添加和水添加的响应在成熟期较枯萎期敏感;N对成熟期叶的N、P含量、N∶P以及枯萎期的N∶P有显著影响,而水分仅对成熟期叶的N、P含量有影响。Knowledge of herbage nitrogen (N)and phosphorus (P)in plants is fundamental to the study of ab-sorption and utilization of nutrients by the plants.In order to better understand limiting factors and plant adap-tion strategies to environmental factors in the grassland ecosystem,water and N enhancement experiments were carried out in a Stipa breviflora steppe.Four treatments were set up:nitrogen addition (ND),water ad-dition (WD),nitrogen and water addition (NWD)and control (CK)with five replicates in a free grazed pad-dock in a S .breviflora desert steppe,Inner Mongolia.The S .breviflora leaf N and P concentrations and their stoichiometry under different treatments were analyzed.It was found that S .breviflora enhanced adaptability to barren habitats by increasing leaf N content.Uptake of N by S .breviflora was limited by low soil N and wa-ter contents.The absolute leaf N and P contents and the N∶P ratio were more sensitive to the environmental addition of N and water in mid season than in late season.The availability of environmental N greatly influ-enced the leaf N and P contents and N∶P ratio in mid season and the N∶P ratio in late season when plants were withering.However,the availability of water only affected the leaf N and P content in mid season and not in late season.

关 键 词：氮素添加 水分添加 短花针茅 氮含量 磷含量 氮磷比 

分 类 号：S543.9[农业科学—作物学]