With semivariogram analysis,this paper studied vertical
variability of soil water of different texture and different fertility
in the suburb of Beijing.The results of semivariogram analysis showed:when cultivating wheat in winter and corn in summer,the range of vertical
variability of soil water was 50-60 cm,the degree of heterogeneity changing with the depth.The nugget variance to sill ratio was 1.41%-9.26%,less than 25%,which meant that soil water had higher
autocorrelation in the range of vertical variability.For different texture,the lower autocorrelation and smaller range of vertical variability,the heavier of the texture of soil.As for different fertility,the degree of autocorrelation and range of vertical variability increased with the fertility.These results have an important effect on the management and utilization of soil water in fields.Moreover,to a definite accuracy the field work in soil water in practice will be reduced on the basis of the rules of vertical variability of soil water.