Study on Spatial Variability of Soil Moisture for Walnut under Drip Irrigation

A total of 435 soil moisture monitoring points in 30 m× 60 m(a branch controls) were layout in Walnut Forestry Centre of Aksu district of Xinjiang.The spatial variability of soil moisture under drip irrigation of walnut fields was analyzed by using geology-statistics method to provide guideline for the soil moisture monitoring program and soil moisture prediction.The results indicated that augmenting the sampling spacing made no difference with variance coefficient of soil moisture while sampling extent was invariable under drip irrigation.The field soil moisture was moderate spatial autocorrelation under different sampling spacing.As the sampling spacing was augmenting,spatial autocorrelation had few diversification.It indicated that the sampling spacing has inapparent influence to spatial variability on micro-scale of drip irrigation.The spatial autocorrelation under the direction of the capillary was obviously bigger than that of branch pipe.Namely the variety under the direction of the capillary caused by structural factor was more evidence and the variability had a strong spatial zonal structure.