Available Microelement Contents in Tobacco Growth Soils of Chongqing

In order to find out the distribution rule of available microelements in soils of Chongqing tobacco growing areas,the contents of available microelements in 155 soil samples of different soil types from different counties in Chongqing were determined and the distribution rule and affecting factors of available microelements were discussed.The results showed that the contents of available Zn,Mo,Fe,Mn and water-soluble Cl were richer or extremely rich in 80%-90% of the samples,B was in serious deficiency and available B was short at different extents in 75.38% of the samples.The differences of available microelement content between areas and soil types were extremely significant.The soil types in the order of comprehensive index of available microelement were purple soil(9.92) mountain yellow brown soil(7.54) black soil(5.47) yellow soil(4.86) calcareous soil(3.60).Therefore,B and Mo fertilizer should be applied to soil types short of available B and Mo.For relieving the damage to tobacco leaf caused by higher contents of Fe and Mn,alkaline soil with lower organic material content could be chosen for tobacco growing.