地统计学及GIS在黑土区域土壤养分空间异质性分析中的应用——以海伦市为例

Spatial Heterogeneity of Soil Nutrients in Blacksoil, China—A Case Study at Hailun County

应用地统计学的方法结合GIS空间分析技术,对海伦市黑土农田区域采集的65个耕层(0—20cm)土壤样本进行了数据处理,对其全量养分含量的空间异质性进行了分析和探讨。结果表明,全碳、全氮和全磷半变量函数曲线的理论模型符合高斯模型,全钾的理论模型表现为指数模型。全碳、全氮属于中度空间相关,其空间变异受结构性因子和随机因子的影响各占1/2。全钾和全磷属于高度空间相关,其变化主要受结构性因子的影响。土壤全碳与全氮和全磷具有极显著的正相关,在空间分布上也与全氮和全磷的空间分布吻合度较高。地统计学分析土壤养分的空间变异特征和1978年海伦县自然资源综合考察对农田土壤肥力调查的结果是吻合的。利用地统计学分析的方法,对区域农业生产合理布局、综合治理水土流失都具有重要的意义。

Geostatistics combined with geographical information system(GIS) techniques were applied to a treatment and analysis of the spatial heterogeneity of soil nutrients in topsoil(0—20cm) at Hailun County of Heilongjiang Province. Sixty-five soil samples were collected from the central farmland of Hailun County. The results indicate that the semivariogram of total C and total P are best described by the Gaussian model; total N and total K are best described by the exponential model. Analysis shows that the spatial correlation of total C and total N at this large scale is moderately dependent, with Nugget/Sill were between 25%～75%; therefore changes in total C and total N are affected by both structural and random factors. The spatial correlation of total K and total P is highly dependent, with Nugget/Sill were less than 25%; therefore, changes in total K and total P are mainly affected by structural factors. There is high spatial correlation between total C and P. Spatial variability results from the geostatistics method were compared to soil fertility survey in 1978 results from Hailun farmland. The analysis is useful to inform strategic planning of farm production, to guide fertilizer application and to control soil erosion and degradation of Blacksoil, in northeastern China.