Effect of banana intercropping pattern and straw compost-return on soil enzyme activity

Field experiments were conducted to investigate the effects of three intercropping patterns (banana-soybean, banana-peanut, and banana-ginger) of banana and two straw compost-returns (2.5 or 1.5 kg per plant) on the activity of urease,?catalase,?alkaline phosphatase, and invertase in orchard soils. Intercropping increases urease,?alkaline phosphatase and invertase activity. The highest activity increase occurs in invertase, followed by alkaline phosphatase and urease. On the contrary, intercropping decreases catalase activity. The order of effect of the intercropping patterns on enzyme activity is ranked as banana-soybean>banana-peanut>banana-ginger>banana monoculture. Significant increases are achieved in invertase and urease activity under the straw compost-return treatment, with the highest increment occurring in invertase (34.6%~39.2%), followed by urease (9.7%~28.7%). While catalase activity is slightly influenced, alkaline phosphatase activity is significantly inhibited by straw compost-return. Under straw compost-return, urease activity increases with increasing dose of straw compost while invertase activity slightly increases. Furthermore, catalase activity decreases when straw compost is lower than 2.5 kg per plant.