Study of C/N ratio of organic materials and its application in the production of natural fertilizer (bokashi)

Abstract

Bokashi is an organic fertilizer made from organic materials through fermentation process. A high quality bokashi should have C/N ratio between 10-20, which normally produced from a mix raw organic material with has C/N ratio of 30. However, many studies have shown a composition of raw organic material without a calculation of C/N ratio. Therefore, the objectives of this study were to gather the initial C/N ratio of various raw material from previous published studies, calculate the C/N ratio, and examine the descriptive characteristic (colour, aroma, and texture) of bokashi made from three selected C/N ratios of raw material (30, 70, and 110) and various length of fermentation (10, 17, and 24 days). This research combined literature reviews and laboratory experimental. For laboratory experimental, Complete Randomise Design (CRD) was applied. The result showed that all bokashi produced from raw material mixture with the C/N ratio up to 110 was still acceptable to be directly applied as a fertilizer. Bokashi produced with longer fermentation time had better texture but lower aroma and colour quality.