宁夏盐池沙化草地土壤质量分析与评价

Soil quality assessment of desertificated grassland in Yanchi,Ningxia

在对宁夏盐池沙化草地生态环境进行调查的基础上,以草地土壤的理化性质:有机质、全氮、碱解氮、速效磷、速效钾、全盐量、pH值、容积质量作为评价指标,应用灰色关联分析法对草地土壤质量进行综合评价.结果表明:整个研究区土壤有机质含量处于较缺乏状态;土壤全氮、碱解氮和速效磷极度贫乏,速效钾的含量丰富;从评价指标的空间变异系数看,pH值最小为2.45%,全盐量最大为65.39%,其余土壤各项指标均呈中等变异强度;土壤质量评价各指标之间相关性分析表明,土壤有机质含量与土壤全氮、碱解氮呈极显著正相关,与容积质量呈极显著负相关,与速效磷、速效钾、pH值、全盐无显著相关关系.容质量与有机质、全氮呈极显著负相关,与碱解氮、全盐量呈显著负相关.根据关联度大小表明研究区总体土壤质量水平属于中等,这与研究区的实际情况相吻合.

On the basis of investigation of grassland environments in Desertification Grassland of Yanchi,Ningxia,Taking organic matter,total N,available N,available P,available K,salt content,pH value and soil bulk density as evaluation indexes,the quality of grassland soil in this region is evaluated by using grey system theory.The results show that content of soil organic matter is still low level,total N and available N is a little low level.The contents of available K is much high level.The results of space variation coefficient of evaluation indexes show that the coefficient of pH value is the lowest among all evaluation indexes,which is 2.45%,and the coefficient of salt content is the highest,which is 65.39%.The results of correlation of evaluation indexes show that soil organic matter has a very significant positive correlation with total N and available N,and a significant negative correlation with available soil bulk density.There is no significant correlation between soil organic matter and available P,available K,salt content,pH value.soil bulk density has a very significant negative correlation with organic matter and total N,and a significant negative correlation with available N and salt content.All the study area soil quality high and low order situation： 12 22 25 4 2 23 6 29 28 11 13 5 11 16 30 20 19 27 10 6 24 21 3 1415 18 26 7 17 9 1.According to the grey correlation shows that the soil quality of whole study area is medium,this conclusion is reasonably in accordance with the study situation.