村级尺度下丘陵区农田土壤氮磷空间变异研究

Research on Soil Nitrogen and Phosphorus Spatial Variability in Hilly Area under Village Scale

运用GIS与地统计学相结合的方法,在村级尺度下研究了渝东北丘陵区农田土壤碱解氮、速效磷的空间变异性。结果表明:在村级尺度下土壤碱解氮、速效磷含量都具有中等程度变异,变异系数分别为40.27%和64.21%。土壤碱解氮半方差函数最佳理论模型为高斯模型,且具有强烈的空间相关性,C0/(C0+C)值为14.5%,空间相关距离为61 m;速效磷以指数模型模拟最好,具有中等程度的空间相关性,C0/(C0+C)值为45.0%,空间相关距离为47 m。土壤碱解氮在东西方向上表现出各向异性,与地形表现出很好的一致性;土壤速效磷在东西、南北方向上都有明显的趋势特征,表现出各向异性。

Statistical methods and GIS technology were used for the analysis of the spatial variability,to reveal the spatial variability of soil alkali-hydrolysable nitrogen ,rapidly available phosphorus under the village scale. The results indicated：In the village scale, soil alkali-hydrolysable nitrogen ,rapidly available phosphorus content has moderate variability.The coefficients of variation were 40.27% and 64.21%. Soil alkali-hydrolysis nitrogen semi-variance function optimal theory model for Gauss models, and had a strong spatial correlation, CO/（C0＋C ）value was 14.5%, the spatial correlation distance was 61 m. Rapidly available phosphorus in exponential model to simulate the best, with a moderate degree of spatial correlation, Co/ （C0＋C）value was 45.0%, the spatial correlation distance was 47 m. The soil alkali-hydrolysable nitrogen in east-west direction on exhibit anisotropic, and terrain showed good consistency. Soil rapidly available phosphorus in the East, North and South direction had obvious characteristics, exhibiting anisotropy.