Vertical Profile of Organic Carbon and Nitrogen Distribution in Different Tea Garden Soil

Five soil types (yellow soil, red earth, moisture sandy soil, alpine meadow soil and purple soil) from tea garden in Wuyishan City were investigated for the content of soil organic carbon (SOC) and nitrogen (N) , storage and distribution.The results showed that SOC and N content and storage differed significantly among five soil types and along soil vertical depths.The SOC and N contents were significantly higher in 0-20 cm soil layer than in 20-40, 40-60 and 60-80 cm soil layers for all five soil types, but the concentration decreased along with the soil vertical depths.The concentration profile of SOC and N indicated the up layer accumulation effect of SOC and N in the soils.Comparing in the same soil layer, the contents of SOC and total N were following in order as alpine meadow soil>yellow soil>purple soil>moisture sandy soil>red earth.The SOC storage in the same soil layer of 0-80 cm was in order as alpine meadow soil (253.29t·hm-2) >purple soil (134.17t·hm-2) >yellow soil (132.44t·hm-2) >moisture sandy soil (102.95t·hm-2) >red earth (46.28t·hm-2) .The soil TN storage demonstrated in the same trend as the SOC storage.The observation in this study showed significant positive correlation of soil organic carbon with total nitrogen, C/N and porosity, but SOC and N concentration on the other hand showed a significant negative correlation with soil bulk density.The SOC and N concentration had no significant correlation with soil moisture and pH value.