Abstract
To examine the use of raw materials to make bark compost that is suitable as a medium for potted plants, we tried composting materials with several C/N ratios and nitrogen contents. On the 14th day from the start of composting, C/N29 had the lowest ammonium content. Ammonium content increased in the order from C/N22 to C/N18. In C/N29, the ammonium content decreased after the 14th day from the start of composting, reaching a hardly detectable level by the 70th day. The ammonium contents in C/N22 and C/N18 remained high at 70 and 28 days after the start of composting, respectively, but were barely detectable on days 112 and 98. According to the relationship between ammonium content and temperature during composting, the end temperature of the fermenting process was estimated to be 36°C, regardless of the C/N ratio. The integrated amount of ammonium contents in C/N18 was almost the same as that in C/N22 ; nevertheless, the nitrogen content of C/N18 was higher than that of C/N22. Therefore, we estimated that the degradation of organic nitrogen compounds in C/N18 was retarded by some factors.