Sustainable compost prepared from oyster mushroom substrate microparticles with domestic wastes as local starters

Oyster mushroom (Pleurotus ostreatus) is one of the high-demand edible mushrooms due to its high nutrition and pharmaceutical compound. However, the mushroom produce spent mushroom substrate (SMS) as a byproduct of mushroom industries, creating various environmental problems. The experiment was done by converting SMS into micrometer-sized particles. Then, the SMS particles were mixed with various domestic wastes as local starters, including Effective Microorganism-4 (EM4) , rice waste, vegetable waste, banana weevil, banana peel, chicken dung, goat dung, and cow dung. The results show that SMS mixed with domestic waste has excellent performance. Specifically, when SMS was mixed with chicken dung, it created compost with the highest performance N-Total (1.01%), P-Total (1.06%), K-Total (1.51%), Ca (1.48%), Mg (0.4%), and C/N ratio (16.97%), indicating that compost already matured. Following the Indonesian National Standard, the prepared compost from SMS mixed with chicken dung is more suitable for the standard requirement. The use of SMS microparticles brings a great impact on the enhancement of the product. The micrometer-sized particles permit a large contact area between the raw components to be contacted and interacted with easily, making them mature quickly in the bioreacto