Variation of Soil Properties of Chinese Fir plantation

The variations of physical,chemical properties and biological characteristics of soil in Chinese fir Cunninghamia lanceolata plantation with different cultural rotations (from one to three) and development stages are studied and analyzed.It is showed that with the increase of rotation,the soik physical properties deteriorate,the pH value decreases and the nutrient content becomes poorer,especially the contents of available P and hydrolytic N.The microorganism quantity and soil enzyme activity change to toward the declination of biological activity.In different development stages,the soil fertility differs.In the stage from young plantation to middle aged plantation,the soil fertiliity decrease while it will increase in the mature stage.But the soil fertility can not be recovered thoroughly.Under present culture system,the successive culture of C.lanceolata plantation will result in the declination of soil complex function,which is an important reason why C.lanceolata plantation can not keep high productivity for a long term.