盐碱地土壤养分和盐分含量的空间变异特征研究

Spatial Variability of Soil Nutrient and Salt Contents in Saline-alkali Land soil

为了研究盐碱地土壤养分、盐分含量之间的相互关系,采用空间自相关、半变异函数和克里金插值方法,对酒泉市盐碱地土壤有机质、碱解氮、速效磷、速效钾、盐分含量的空间变异特征及其影响因素进行分析.结果表明,研究区土壤碱解氮、速效磷、速效钾含量平均值分别为64.30、15.50、121.40 mg/kg,有机质和盐分含量平均值分别为12.80、7.49 g/kg,养分和盐分含量的空间变异系数均表现为中等变异;空间变异性分析发现,研究区5类土壤因子块金系数均小于0.25,表明其主要受地形、成土母质和植被覆盖度等结构性因素的影响;盐碱地土壤中有机质、碱解氮、速效钾含量南高北低,而速效磷、盐分含量从东到西高、低交替循环;相关性分析表明,盐碱化土壤有机质含量、碱解氮含量与盐分含量呈极显著负相关(P<0.01),但速效磷含量与盐分含量呈显著正相关(P<0.05).这说明土壤养分含量在一定程度上影响土壤盐分含量状况.

In order to study the correlation between soil nutrients and salinity contents in saline-alkali farmland,spatial autocorrelation,semi-variogram and Kriging interpolation methods were used to analyze the organic matter,alkaline nitrogen,available phosphorus,available potassium,and salinity contents of saline-alkali arable land of Jiuquan City,and the spatial variability of their contents and its influencing factors were analyzed.The results showed that,the average contents of soil alkaline nitrogen,available phosphorus,available potassium were 64.30,15.50,121.40 mg/kg respectively,and organic matter and salt contents were 12.80,7.49 g/kg,respectively.The spatial variation coefficients of nutrient and salinity contents were both moderate variation.Spatial variability analysis found that the nugget coefficients of the five soil factors in the study area were all less than 0.25,which indicated that they were mainly affected by structural factors such as terrain,parent material and vegetation coverage.The contents of organic matter,alkaline nitrogen,and available potassium in saline-alkali arable soil were higher in south of the study area than those in the north,while the available phosphorus and salinity contents alternated from east to west in high and low cycles.The correlation analysis showed that the contents of organic matter,alkaline-hydrolyzed nitrogen and salinity in saline soil were extremely significantly negatively correlated(P<0.01),but the content of available phosphorus was significantly positively correlated with salinity content(P<0.05).This indicates that soil nutrient content affects soil salinity content to a certain extent.