GIS支持下的典型油菜地土壤养分特性空间变异研究

Spatial variability analysis of soil nutrients characteristics in the rape field based on GIS

采用地理信息系统及地统计学方法,分析了典型油菜地土壤pH值、有机质、全氮、速效磷、速效钾和有效硼等养分的空间变异规律,并绘制养分空间分布图,为油菜地精细管理与有效施肥提供理论依据.结果表明：5种养分的变异系数均在16.88％～65.42％之间,属于中等程度的变异.全氮和速效钾的块金系数小于0.25,具有强烈的空间相关性;pH值和其他3种养分则具有中等程度的空间相关性.经过半方差函数分析,采用高斯模型、指数模型、球状模型和线性模型对养分参数进行拟合,并利用GS＋与ArcGIS绘制养分分布图,结果表明,研究区土壤理化性状存在明显的空间差异,总体表现在西南区域的有机质、全氮、有效磷、速效钾和有效硼等各个养分的含量都较高,具备很好的油菜种植生产条件,东北部区域养分含量普遍较低,其主要影响因素为结构性和人为随机性因素.

In this paper, geo-statistics combined with GIS was applied to analyze the spatial variability of soil nutrients characteristics including pH value, organic matter, total nitrogen, available phosphorus, available potassium and available boron in the rape field, and scatter diagrams of the distribution of soil nutrients were constructed, to provid a theoretical basis for effective fertilization. The results showed that all of soil nutrients in the coefficient of variation ranged from 16.88% to 65.42%, which belonged to moderate degree of variation. Nitrogen and potassium＇s nugget coefficient was less than 0.25, with a strong spatial correlation; pH value and three other nutrients had moderate spatial correlation. After a semi-variance function analysis, the Gaussian model, exponential model, spherical and linear model were used to fitt model parameters. The results indicateal that there was significant spatial difference in soil physical and chemical characteristics of the study area. In the southwest region, nutrient content was high, in northeast regional nutrient content was generally low, and its main influencing factors were the structural and human randomness factors.