Effect of raw materials C/N ratio on the quality of Bokashi

Authors

• Irfan * ¹
• Dewi Yunita ¹
• Muhammad Fadhil ¹
• Fauzan ²

1. Department of Agricultural Product Technology, Agriculture Faculty, Universitas Syiah Kuala, Banda Aceh, Indonesia
2. Magister Programme of Agricultural Industry Technology, Faculty of Agriculture, Universitas Syiah Kuala, Banda Aceh, Indonesia

Abstract

Purpose: To assess the effect of C/N ratio in organic raw materials on the quality of bokashi and to obtain the proper C/N formulation of raw materials and fermentation time for bokashi production.

Method: The bokashi was made using a Completely Randomized Design (CRD) with two factors: the C/N ratio in raw materials (R: 30, 70, 110) and the fermentation time (L; 10, 17, 24 days). Then, the bokashi was evaluated for microbial and chemical properties. In the second stage, the bokashi was made using raw materials with C/N of 30 and 150 and fermentation time (0, 10 days) with 5 replications for analyzing the C/N. The pH and temperature were also observed every day during 10 days.

Results: The highest TCC (1.44×10¹¹ CFU/g) was in the bokashi which produced from raw materials with C/N of 70. In general, C/N of bokashi was lower than that of initial raw materials; however, 10 days fermentation was not sufficient to decompose organic matter in raw materials with a C/N of 150 perfectly. Daily observations of the pH and temperature during 10 days fermentation showed a continuously increasing of pH, while temperature first increased and began to experience a constant decrease starting on the 8^th day.

Conclusion: A good quality bokashi which match the soil C/N ratio range of 10-20 can be produced from organic raw materials with C/N of 30 to 70 within 10 days fermentation as well as from raw materials with C/N of 110 after being fermented for 24 days.

Research Highlights

• Organic waste in Indonesia generally presents a C/N ratio above 30.
• A good quality bokashi which match the soil C/N ratio range of 10-20 could be produced from organic raw materials with C/N of 30 to 70 within 10 days fermentation.
• Raw materials with a C/N of 110 can be decomposed after being fermented for 24 days.

Graphical Abstract

Keywords

• Compost
• Organic waste
• Biodecomposer
• MOL (Local Microorganisms)