海伦黑土有机碳和速效养分空间异质性分析

Analysis for Spatial Heterogeneity of Organic Carbon and Available Nutrients in Black Soil Region of 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,并对其全碳、碱解氮、速效磷和速效钾含量的空间分异特征进行了研究和探讨.结果表明,海伦黑土全碳、碱解氮和速效钾半变量函数曲线的理论模型符合高斯模型,速效磷的理论最佳模型为球状模型.全碳、碱解氮和速效磷表现为中度空间相关,其空间变异受结构性因子和随机因子的影响各占一半.速效钾属于高度空间相关,其变化主要受结构性因子的影响.土壤全碳与碱解氮具有显著的正相关,二者在空间分布上吻合度较高. 全碳和碱解氮都与速效钾呈显著负相关.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黑土农田土壤肥力调查的结果具有相同的异质性.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 GIS was applied to analyze the spatial variability of soil nutrients in topsoil (0-20cm) in Hailun county of Heilongjiang province. Sixty five soil samples were collected from the central farmland of Hailun. The results indicated that the semivariogram of total C ,available N and available K were best described by the Gaussian model, while available P was best fitted by the Spherical model. The analysis also showed that the spatial correlation of total C, available N and available P at this large scale was moderately dependent, whose Nugget/Sill were between 25-75%, therefore the changes of them were affected by both structural and random factors. Available K was highly dependent, whose Nugget/ Sill were less than 25%, thus the change of it was greatly affected by structural factors. There was significant correlation between total C and available N ; and low correlation with available P; significant negative correlation between total C ,available N and available K. The results of spatial heterogeneity by using method of geostatistic was closely approached with that the survey of soil fertity of farmland in Hailun in 1978. The analysis would be very useful for strategic distribution of farming production, guideline of fertility application and control of soil erosion and degradation in Blacksoil, Northeast of China.