银川平原草甸湿地土壤养分特征与植物响应

Soil Nutrient Characteristics and Plant Response in Meadow Wetland in the Yinchuan Plain

为探究草甸湿地土壤养分特征,阐明草甸湿地土壤养分对植物养分的影响,在银川平原选取3种生境的草甸湿地(沼泽草甸、典型草甸和盐生草甸)作为研究对象,通过野外调查、实验室分析,结合经典统计学方法对土壤养分及植物养分进行分析。结果表明:①水平梯度上,除全磷(TP)外,3种草甸湿地之间土壤养分含量在土层020cm变化显著(P<0.05)。②在垂直梯度上,全氮(TN)、碱解氮(AN)在盐生草甸中垂直变化不显著(P>0.05),但在典型草甸与沼泽草甸垂直方向上波动幅度较大;TP在草甸湿地土壤中垂直变化不显著(P>0.05);速效磷(AP)与速效钾(AK)在草甸湿地表层具有一定程度的富集效应,并且在不同草甸湿地土层垂直方向上变化显著(P<0.05)。③土壤中C、N和P含量的变化趋势一致;AK与土壤P具有显著的相关性(P<0.05)。④草甸湿地植物养分均表现为N限制,其中C∶N、C∶P与土壤养分呈负相关,植物N∶P受土壤有机碳(SOC)、AN影响较为显著。

In this study,three types of meadow wetlands (marsh meadows,typical meadows and salty meadows)in the Yinchuan Plain were selected as the research subjects. An analysis of soil nutrients and plant nutrients was conducted with classical statistical methods through field investigation and laboratory analysis. The main conclusions are as follows:① At the horizontal gradient,except for soil total phosphorus (TP),the difference of soil nutrient level in soil layer of 0-20 cm in depth among the three meadow wetlands was obvious (P < 0. 05).② The vertical variation of soil total nitrogen (TN) and soil alkali-hydrolyzed nitrogen (AN) in the salty meadow was not obvious (P > 0. 05),but the vertical fluctuation in the typical meadow and swamp meadow was larger. The vertical change of TP in meadow wetland soil was not obvious (P > 0. 05). An enrichment of soil available phosphorus (AP) and available potassium (AK) occurred in topsoil in the meadow wetland to a certain extent,and the vertical change was very obvious (P < 0. 05).③ The change trends of C,N and P contents in soil were consistent. There was a significant correlation between soil AK content and soil P content (P < 0. 05).④ Plant nutrients in the meadow wetland was affected by N,in which the C∶ N and C∶ P were negatively correlated with soil nutrients,and plant N∶ P was significantly affected by soil organic carbon (SOC) and AN.