橡胶园土壤肥力指标的小尺度空间变异Ⅰ:0～20cm土层

Micro-scale Spatial Variance of Soil Fertility Indices in the Rubber PlantationⅠ: 0～20 cm Soil Layer

在84 m2区域内对橡胶园土壤按0.5 m×1 m网格进行取样(n=168),对5种土壤肥力指标进行地统计学分析。结果表明:全氮、有效磷、速效钾、有机质和pH值的半方差函数均可用指数模型描述,其各自变程分别为1.44、1.65、3.36、1.20和1.74 m,均表现出强空间自相关关系。从土壤肥力指标的空间分布特征来看,全氮、有效磷、有机质呈现出明显的"肥岛"效应,其中全氮"肥岛"面积最大,影响距离最远;有效磷的"肥岛"面积最小,与周围浓度成倍数递减,成同心圆结构;有机质的空间分布特征介于二者之间;速效钾斑块面积分布比较均匀,与土壤母质类型有关。

The objective of this study was to explore the micro-scale spatial variance of soil fertility indices in the rubber plantation. 168 soils were sampled by 0.5 m×1 m grid within a 84 m2 region. Soil fertility indices selected included total N, available P, available K, soil organic matter and pH. Geostatistics method was used to analyze the data. Results showed that the semi-variance of the total N, available P, available K, soil organic matter and pH could be simulated by the exponential model. The ranges for total N, available P, available K, soil organic matter and pH were 1.44 m, 1.65 m, 3.36 m, 1.20 m and 1.74 m. The geostatic analysis showed these soil indices were strongly heterogeneity. The distributions of soil fertility indices were obviously different. Contour maps of total N, available P, soil organic matter showed as a island of fertility. Area of the island of total N was the biggest, soil organic matter was in the following, available P was the smallest. The contour maps of available K showed relatively uniformity, which may be related to the parent material of the soil.