| The distributing and changing characteristics and content of soil heavy metals was studied using methods of field survey and sampling, indoor analysis, and pollution index were used to investigate the soil environmental quality in the tea plantations of Changsha Baili Tea Zone. The results showed that the content of soil total Pb, Hg, Cd, Cr, As, Ni basically was in the soil background value, their averages were 42.7, 0.068, 0.074, 92.2, 12.4 and 19.5 mg/kg respectively. The content of heavy metals was lower than the standard of Environmental Qualification of Nuisance Free Tea Producing Area (NY 5020-2001). Simultaneity, soil environmental quality in tea plantations of Baili Tea Zone, it answered for the second grade of State Environmental Quality Standard for Soils (GB 15618-1995), achieved safe class, and the content of soil Hg, Cd, Ni accorded to the first grade of GB 15618-1995, these results showed the Changsha Baili Tea Zone were propitious to develop nuisance free tea production. Besides the single pollution index of Cr was 0.837 and in warning class at the tea plantation of Xiangfeng, the others were all less than 0.7, and in the safe class. The integrated index of 6 tea bases was all less than 0.7, in the safe class, the soil environmental quality was cleanness on the whole at Changsha Baili Tea Zone, and the soils were suitable for non-polluted agricultural production. |
