Abstract: Soil fauna is one of the significant biological indicators of soil environment. Understanding the differences of community structure of soil fauna under tea plantations of different cultivars can provide scientific basis for the selection of advantageous tea cultivars in the process of returning croplands to tea gardens. Soil samples from tea plantations with four major tea tree cultivars (Fuding Dabaicha, Chuancha No. 3, Chuanmu No. 217 and Chuannong Huangyazao) were collected from Zhongfeng Ecological Tea Garden in Mingshan Township, Yaan City, Sichuan Province. Soil fauna from 0-15 cm soil layer was extracted by three different methods: handsorting approach, modified Tullgren method, and Baermann’s method. Results showed that the soil fauna belonging to five groups, 10 classes, and 23 phyla were observed in the tea garden. The plantation of Fuding Dabaicha had significantly higher abundance of soil fauna, compared with other three tea cultivars. Nematoda were the dominant group in the plantations of all the four tea cultivars. There was higher richness of soil fauna groups in the plantations of Chuanmu No. 217 and Chuannong Huangyazao than those of Fuding Dabaicha and Chuancha No. 3. The Shannon index and Simpson evenness index of soil fauna in the plantations of Chuancha No. 3 were significantly higher than those of the other three tea cultivars. Soil fauna richness index was positively correlated with soil organic C and available P content, while Simpson evenness index was negatively correlated with available K. Therefore, enhancing soil organic C and available P contents would increase the richness of soil fauna community.

Key words: irrigation method, soil water, nitrate nitrogen, winter wheat, irrigation and N application, growth and development