县域尺度橡胶园土壤全氮空间分异特征及其影响因素

Spatial Variability of Soil Total Nitrogen in Rubber Plantations and Related Influencing Factors at a County Scale

根据儋州市2 511个橡胶园表层土壤样点数据,采用地统计和多元逐步线性回归方法,对该区土壤全氮空间变异特征进行分析,并探讨了不同环境变量对其空间分布的影响。结果表明,研究区橡胶园土壤全氮含量为0.22-2.62 g/kg,平均值为0.71 g/kg,处于缺乏水平。土壤全氮半方差模型为指数模型,块金比为0.159,具有强烈的空间自相关性,主要受结构性因素的影响。逐步线性回归分析进一步表明结构性因素中的成土母质和平均降雨量为影响橡胶园土壤全氮空间分异的主要因素。

A total of 2511 soil samples were collected from a horizon of rubber plantations in Danzhou County. Soil total nitrogen（TN） contents were analyzed. The geostatistical method was employed to analyze spatial variability of TN. Then multiple stepwise linear regression（MSLR） was applied to identify the main factors influencing variation of TN. Results showed that TN contents ranged from 0.22 to 2.62g/kg with a mean value of 0.71 g/kg, which indicated that the TN level was low. Semi-variogram of TN was the exponential model. Value of nugget to sill ratio was 0.159, which implied that TN had a strong spatial dependence and this spatial dependence was mainly controlled by structural factors. The MSLR analysis further found that parent materials and the mean precipitation were the main factors influencing TN variability of rubber plantation in this study area.