Distribution of Zn and Cu in rock,soil and navel orange tree system in Zigui County, Hubei Province

The distribution of Zn and Cu in rock, soil and navel orange tree system in Zigui County was analyzed. Results show differing characteristics of Zn and Cu in navel orange fruits, rocks and soils of the system. The distribution of Zn and Cu follows the universal electrochemical displacement series in the system. Zn/Cu ratio in the system is in the order of rock＜soil＜navel orange fruits＜navel orange stem. Biogeochemical circulations of Zn and Cu are different in the system, with Zn always displacing Cu. Biological enrichment coefficient of Cu and Zn can be represented by a linear regression equation:Zn=0.006+0.024×Cu(R=0.96).