Abstract:

Producing organic fertilizer by the fermentation of macadamia peel was studied to provide method and a basis for the utilization of macadamia peel waste. By laboratory test, the suitable auxiliary material was selected as wheat bran with 3% of bacterial agent inoculation and 60% water content. The dried macadamia peel was used as raw material for composting, wheat bran was added, and the decomposition was conducted with aerobic bacteria. The changes of nutrients and organic matter contents in different fermentation stages were measured and evaluated. The results showed that: when wheat bran was used as auxiliary material and bacteria agent was inoculated at 3% amount, under the condition of water content maintained at 50%-60% in the early stage (the first 40 days) and no water addition in the late stage (after the first 40 days), after 55 days of composting, the carbon to nitrogen ratio was lower than 20%, the organic matter content was 89.1%, the total nitrogen, phosphorus and potassium was 5.19%, pH was 6.92, and the water content was 25.79%. The products had brown color, no odor and soft texture, and were completely decomposed, which could meet the national standards of organic fertilizer. In conclusion, the fermentation of macadamia peel waste to produce organic fertilizer is an effective way of waste utilization.

Key words: macadamia, peel, fermentation, utilization, organic fertilizer