Abstract: 【Objective】 The aim of this experiment was to research the best application pattern of beer sludge compost on apple trees and yield-increasing mechanism. 【Method】 The effects of beer sludge compost treated with three application methods including blending(H), mulching (F), blending and mulching (HF) on the growth of apple trees, leaf physiological characteristics and the root morphology. 【Result】The test results were as follows: The beer sludge compost with different application methods could significantly promote apple seedlings growth. H, HF treatments could significantly enhance dry stem diameter, branch diameter, leaf area per leaf, and leaf area per plant. Chlorophyll a, Chlorophyll b, carotenoid content and Pn were significantly enhanced, chlorophyll a/b and transpiration rate were significantly reduced compared with CK. Beer sludge compost could enhance leaf antioxidant enzyme activities and reduce harm, H and HF treatments were better than F. Root length, root surface area, root volume, root fresh weight, and root number were significantly higher than CK with H, F, HF treatments. Apple seedlings roots growth could be induced and promoted with beer sludge compost, and H and HF treatments were better. The root vigor of H, F, and HF were, respectively, increased by 53.68%, 40.50%, and 77.72% compared with CK. 【Conclusion】The beer sludge compost was applied with three different methods could promote the growth of apple trees, and improve the physiological indexes of leaf and root. In the whole, HF treatment integrated the advantages of H and F treatments, and it was the most effective application method.

Key words: beer sludge compost , apple , growth , physiological characteristics , root morphology