晋中市土壤养分空间分布与影响因子的相关性

土壤养分是土壤肥力的基础,掌握其含量及分布特征对科学施肥具有重要意义。为此,运用ArcGIS技术与相关分析,研究了山西省晋中市主要土壤养分的空间分布规律,及其与海拔、用地类型间的关系。结果表明:(1)晋中市pH值平均为7.97,土壤整体呈碱性;土壤养分含量在不同的区县中差异较大。(2)研究区表层土壤SOM、TN、TP和TK平均含量分别是1.42%、0.08%、0.07%、1.97%,依据国家土壤第二次普查的养分分级标准,晋中市的表层土壤SOM、TN、TP含量偏低,平均水平分别为四级、四级、五级,而TK含量较高,平均水平为三级。(3)随着海拔的增高,土壤SOM平均含量呈先增加后减少的趋势,TN平均含量明显增加,而土壤TP和TK的平均含量变化趋势不明显。(4)用地类型与土壤养分的相关性分析表明,海拔733—1500m范围内,耕地的SOM、TN、TP平均含量均明显高于林地、未利用地和自然保护区,而TK平均含量明显低于其他用地类型;在海拔高于1500 m的耕地中SOM、TN、TP平均含量均低于其他用地类型。在样点全部覆盖的海拔范围内,海拔与TN含量呈极显著正相关,与SOM、TP和TK的相关性未达显著水平。

Study on soil nutrient spatial patterns and their driving factors in Jinzhong

Soil nutrients are the foundation of soil fertility, and it is of great significance in the science of fertilization to master soil nutrient content and distribution characteristics. Therefore, we used ArcGIS technology and correlation analysis to evaluate the spatial distribution rule of the primary soil nutrients in Jinzhong city, Shanxi Province, and its relationship with the type of land. The results showed the following:(1)The mean pH of Jinzhong city soil was 7.97,and all of the soil was alkaline; the nutrient contents of soil varied greatly across counties.(2) The average contents of SOM,TN,TP, and TK in the study area were1.42%,0.08%,0.07%, and 1.97%, respectively. According to the second national soil survey of nutrient classification standards, the surface soil SOM, TN, and TP contents in Jinzhong were low, and the average levels were level four, level four, and level five respectively; however, the TK content was high with an average of level three.(3) With an increase in altitude, the average content of soil SOM increased first and then decreased, the average content of TN significantly increased, and there were no obvious trends in the changes of soil TP or TK.(4) Land-use type and soil nutrient correlation analysis showed that at altitudes of 733-1500 m, SOM,TN, and TP contents were significantly higher than their averages in unused cultivated land and nature reserves, and average TK content was significantly lower than that in other land-use types; the average contents of SOM,TN, and TP in the cultivated land above 1500 m were lower than those of other land types. Within the elevation range covered by the sample points, elevation was significantly correlated with TN content, but the correlations between elevation and SOM,TP, and TK were not significant.