关键词: 地统计学, 全氮, 碱解氮, 三次样条插值, 茶园

Abstract: Studies on the spatial variability of nitrogen and its correlation with particle components in hilly tea plantation soil are important to the improvement of nitrogen utilization ratio and soil management. The methods of classical statistics and geostatistics were applied to analyze the spatial variability of nitrogen and its correlation with particle components in soil of Mengding tea plantation. The results showed: ①The total nitrogen and alkali-hydrolyzable nitrogen content were moderately spatial dependent. The rates of nugget to sill were 35.5% and 28.5%. The spatial autocorrelation ranges of soil total and alkali nitrogen were 843 m and 1149 m. Structural factors were the major factors affecting the spatial variability of the total nitrogen and alkali-hydrolyzable nitrogen content. The anisotropic structures of the total nitrogen and alkali-hydrolyzable nitrogen content were not the same as each other, but both of them had an obvious anisotropic structure in the southeast part and weaker in the northeast part. ②Analysis by the method of Kriging showed that the equivalence of the total nitrogen and alkali-hydrolyzable nitrogen content distributed from northeast to southwest in the aclinic direction of the slope, and increased along with the elevation of altitude in the vertical direction of the slope. ③The total nitrogen and alkali-hydrolyzable nitrogen contents were negatively correlated to the colloid clay (<0.0001 mm), but had not obvious relation to fine clay (0.0001~0.0005 mm), and were positively correlated to skeleton clay, fine silt and medium silt (0.0005~0.01 mm).

Key words: geostatistics, total nitrogen, alkalized-hydrolyzable nitrogen, cubic spline interpolation, tea plantation soil