施磷水平对盐碱地柳枝稷碳氮磷生态化学计量特征的影响

Effects of Phosphorus Application Levels on the Ecological Stoichiometric Characteristics of Carbon,Nitrogen and Phosphorus of Switchgrass(Panicum virgatum)in Saline-Alkali Land

为探究不同施磷水平对盐碱地柳枝稷叶片与土壤碳(C)、氮(N)、磷(P)含量及其生态化学计量比的影响,本研究以宁夏大学西大滩盐碱地综合改良利用核心试验站的两种生态型柳枝稷为研究对象,设不施磷(0)、施低磷P2O530 kg·hm^(-2)(30)和施高磷P2O590 kg·hm^(-2)(90)3个水平,分析比较了2019-2020年低地型品种Alamo和高地型品种Pathfinder柳枝稷叶片与土壤C,N,P含量及其生态化学计量变化规律。结果表明:连续2年施磷处理条件下,Alamo和Pathfinder品种柳枝稷叶片C,N,P生态化学计量特征差异显著。Pathfinder品种的C、N、P含量显著高于Alamo品种。就施磷水平而言,施高磷影响更为显著。连续2年施磷处理可以有效提高土壤有效磷含量和磷酸酶活性,降低土壤pH值和盐分含量。柳枝稷叶片与土壤化学计量特征之间存在较强的相关关系。因此,施磷处理有效改变了柳枝稷叶片和土壤C、N、P含量及化学计量比,为揭示盐碱地农业生态系统元素平衡提供一定的参考价值。

In order to recognize the effects of different phosphorus application levels on the leaf and soil carbon(C),nitrogen(N),phosphorus(P)contents,and their ecological stoichiometry in switchgrass(Panicum virgatum)of saline-alkali areas,this study focused on two ecotypes of switchgrass grown in the XiDatan Saline-Alkali Soil Comprehensive Improvement and Utilization Core Experimental Station of Ningxia University.Three phosphorus application levels were set up:no phosphorus application(0),low phosphorus application of P 2O 530 kg·hm^(-2)(30),and high phosphorus application of P 2O 590 kg·hm^(-2)(90).The study analyzed and compared variations of C,N,P contents in leaf and soil,and ecological stoichiometry in the lowland variety Alamo and the upland variety Pathfinder during the years 2019-2020.The results indicated that under consecutive phosphorus application for two years,there were significant differences in the ecological stoichiometric characteristics of leaf C,N,P between Alamo and Pathfinder varieties,with the higher levels of C,N,and P in the Pathfinder variety.The impact was more pronounced under high phosphorus application.Consecutive phosphorus application for two years effectively increased the soil available phosphorus content and phosphatase activity while decreased soil pH and salt content.There was a strong correlation between leaf and soil chemical stoichiometric characteristics of switchgrass.In summary,phosphorus application effectively altered leaf and soil C,N,P contents,and stoichiometric ratios,providing valuable insights for understanding the elemental balance in agricultural ecosystems of salt-affected areas.