Spatial Variability and Sampling Strategy of Soil Nutrient in Southeast ChinaI.Soil Property and Macro-nutrient

Based on the data from 6 natural villages of 6 provinces in southeast China,the spatial variability and rational sampling strategy of soil pH,organic matter,available N,P and K was studied using ASI method and Geo-statistics.Results showed that:(1) Soil pH value and organic matter content were relatively stable soil properties.In the studied area their spatial variability was rather small and showed almost normal distribution.As the fertilization soil elements,their spatial variability was quite great and showed obviously negative distribution.(2)The general variability of some soil property or macro-nutrient was basically similar,while the structure of semi-variance was quite different among the villages.(3)Stratified and Rational Distributed Sampling method was recommended to determine the rational sampling quantity of soil nutrients which showed obviously negative frequency distribution.The sampling quantity obtained by Simple Random Distributed Sampling method was still a good reference.