Abstract
The high volume of organic waste generated in urban areas calls for effective and sustainable management solutions. Kampoeng Pintar Oase Surabaya still relies on the commercial bioactivator EM4, which is relatively unaffordable; therefore, an environmentally friendly local bioactivator alternative is required. This study aimed to evaluate the effect of local microorganisms (MOL) derived from rotten tempeh and stale rice on composting duration and compost quality. MOL was produced by fermenting rotten tempeh, stale rice, and sugarcane molasses for 14 days. Composting was then conducted using EM4 and MOL treatments, each with three replicates. Composting duration and physicochemical characteristics were analysed descriptively based on laboratory results from BSPJI Surabaya. The results of the study showed that rotten tempeh and stale rice MOL accelerated the composting process to an average of 23 days, compared to 27 days for EM4. The compost produced was dark brown in colour, had an earthy aroma, and contained 1.13% N, 0.48% P, and 6.95% K. The total N+P+K content of 8.56% indicates that the compost meets the minimum requirements for solid organic fertiliser as stipulated in Ministry of Agriculture Regulation No. 01 of 2019.