科尔沁沙地二龄紫花苜蓿草地土壤养分及化学计量特征研究

Study on soil nutrients and stoichiometry of 2nd yearalfalfa pasture in Horqin sandy land

摘要:

为明确科尔沁沙地二龄紫花苜蓿(Medicago sativa)草地土壤养分含量及化学计量特征,以原生草地为对照,分层采集0~100 cm土壤样品,分析不同土层土壤碱解氮、有效磷、速效钾、有机碳、全氮、全磷质量分数并计算碳氮磷化学计量比。结果表明:二龄紫花苜蓿草地0~100 cm土壤碱解氮、有效磷、速效钾、有机碳、全氮、全磷质量分数分别为38.58~78.1 mg/kg、23.01~46.08 mg/kg、60.66~119.74 mg/kg、3.136~8.878 g/kg、0.253~0.953 g/kg、0.476~0.783 g/kg,均值较原生草地分别增加62.55%、-6.57%、19.68%、48.30%、100.81%、40.50%;二龄紫花苜蓿草地表层(0~10 cm)土壤碱解氮、有效磷、速效钾、有机碳、全氮、全磷质量分数分别降低53.91%、16.12%、50.09%、66.76%、70.81%、37.65%;在10~100 cm土层,二龄紫花苜蓿草地土壤养分质量分数(除有效磷外)均有所提高;二龄紫花苜蓿草地土壤C/N、C/P、N/P较低,均值分别为9.602、0.992、9.189,C、N、P元素的缺乏程度为C＞N＞P;土壤全氮质量分数对土壤C/N、N/P的影响最大,土壤有机碳质量分数对C/P的影响最大。

Abstract:

The soil nutrient content and stoichiometry characteristics of 2nd year alfalfa(Medicago sativa) pasture in Horqin sandy land were studied by using the natural grassland as the control.Soil samples in 0~100 cm soil layer were collected to measure the soil AN,AP,AK,SOC,TN and TP contents and calculate the C,N and P stoichiometry.The result showed that the ranges of soil AN,AP,AK,SOC,TN,and TP contents were 38.58~78.1 mg/kg,23.01~46.08 mg/kg,60.66~119.74 mg/kg,3.136~8.878 g/kg,0.253~0.953 g/kg and 0.476~0.783 g/kg respectively.And their average values increased by 62.55%,-6.57%,19.68%,48.3%,100.805% and 40.503% compared to the natural grassland respectively.The contents of soil AN,AP,AK,SOC,TN and TP in 0~10 cm layer reduced by 53.91%,16.12%,50.09%,66.76%,70.806% and 37.653%;In 10~100 cm layer,the soil nutrient contents (except AP) increased;The soil C/N,C/P and N/P were lower,with average values of 9.602,0.992,and 9.189,respectively,and the deficiency ranking of C,N and P was C＞N＞P;Soil C/N and N/P were mainly controlled by soil total nitrogen content and C/P was mainly controlled by soil organic carbon content.