Content of available copper and its distribution in tobacco-growing soil from Xiangxi

In order to understand the distribution of available copper contents in tobacco growing soils in Xiangxi,distribution frequency of available copper contents among different counties,soil types,altitudes were analyzed by both classic statistics and geostatistics with 488 soil samples.The results were as follows:(1) Available copper contents in the tobacco soils were little higher with a mean of 2.125 mg/kg,range of 0.024～7.840 mg/kg and variation coefficient of 69.98%.About 13.81% of the soil samples from available copper contents were suitable for tobacco cultivation.(2) There were extremely significant differences of the available copper contents among the different counties and the order was FenghuangHuayuanLuxiBaojingGuzhangYongshunLongshan.(3) There were extremely significant differences of the available copper contents among soil types and the order was paddy fieldred ash soilyellow brown soilyellow soilred soillime soil.(4) There was extremely significant differences of the available copper contents among the altitudes,and the richest ones were the groups of(600m,800m).(5) The kriging interpolation map indicated that the spatial distributions of available copper were plaques shape and the available copper reduced from south to northern.