Abstract:In this study, the effects of different locations away from the fan on the fermentation efficiency of vegetable wastes mixed with mushroom residue and vinegar residue in aerobic-membrane composting reactor were investigated. Vegetable wastes, vinegar residue and mushroom residue were mixed in a fresh weight ratio of 1:1:3, transferred into aerobic-membrane composting reactor, covered with gas flow membrane, and aerated via the bottom of pile body for 30 days. Samples were collected from 1.5, 4.5, 9.0, 13.5 and 16.5 m positions away from the fan to evaluate the variations of physicochemical properties such as temperature, water content, pH, C/N ratio, germination index and nutrient contents in these samples during the composting. The results showed that during composting, differences of the fermentation efficiency at different locations away from the fan were observed to some extent. Total nutrient contents of decaying materials at 1.5, 4.5 and 9.0 m away from the fan were higher than 5% with the values of 5.31%, 5.20% and 5.27%, respectively; however, the total nutrient contents of decaying materials at 13.5 m and 16.5 m away from the fan were less than 5%, only 4.94% and 4.83%, respectively. At the end of composting, the germination index of decaying materials at each site were all above 80%, with the values of 102.8%, 89.3%, 98.0%, 82.4% and 85.5%, respectively. The results of field experiment showed that compared with application of raw materials, amended with decaying materials increased cowpea yields, especially for treatments added with decaying materials collected from 1.5 m, 4.5 m and 9.0 m sites away from fan, the yields of which increased by 1.8%, 4.52% and 6.78%, respectively, compared with chemical fertilizer treatment. To sum up, this study observed that in the air flow membrane composting process, materials at different locations away from the fan can be fermented, and the decaying materials closer to the fan have higher nutrient contents and better plant growth promotion effect in the field condition.