Abstract: The effects of earthworm on soil enzyme activities, microbiomass carbon, microbiomass nitrogen and the growth of apple tree were studied by pot experiment, using the orchard cinnamon soil, brown soil and fluvo-aquic soil and two-year old ‘Red Fuji’app le (Malus domestica Borkh. ) trees smaterials. The results showed that the earthworm enhanced the activities of soil urease, acid phosphatase and alkalin phosphatase, and increased microbiomass nitrogen in the three kinds of soils, in which the urease activity in brown
soil, the alkalin phosphatase activity in fluvo-aquic soil and the microbiomass nitrogen in brown soil increased 78.9%, 170.0% and 180.4% respectively. The treatment of earthworm increased the microbiomass carbon in cinnamon soil and fluvo-aquic soil, and the increased degree of that in fluvo-aquic soil is the largest, which reached 299.2%. The root activity, root growth and new shoots growth of the app le trees in the soils treated by earthworm increased significantly; The root activity in brown soil, the growth of root in cinnamon soil and the growth of new shoots in fluvo-aquic soil were the highest respectively in the three kinds of soils treated by earthworm.

Key words: apple, soil, earthworm, enzyme, microbiomass carbon, microbiomass nitrogen