Study of Soil Fertility and Water Retention Properties of Six Kinds of Forest Types in Different Time of Natural Forest Protection District of Guizhou Province

[Objective] The aim was to study the soil fertility and water retention properties of six kinds of forest types in natural forest protection district of Guizhou Province.[Method] Plots of six kinds of forest types were set up at the same time,the forest soil was investigated and analyzed two times in 2006 and 2009.[Result] pH value was slightly lower;A layer of soil fertility increased significantly higher than the B horizon.Some indicators such as organic matter,cation exchange capacity,total nitrogen,total phosphorus,hydrolysis of nitrogen,potassium were increased,and phosphorus,total potassium two elements was reduced.Soil fertility of six forest types all showed an increasing trend,but the soil fertility of natural fertility was significantly higher than the plantation's.Soil bulk density was decreased,but porosity was increased.Soil water storage capacity of various forest types were all increased.[Conclusion] it provided a reliable scientific reference for the natural forest protection project in Guizhou Province.