Abstract
The following findings were obtained from the experiments conducted to accelerate composting fermentation of pig excreta and to improve the quality of the compost thus produced.
1) Maintaining a high temperature (60°C) for the fermentation proved to be of benefit for decomposition of hemicellulose. Decomposition of cellulose was more favorable with a moderate temperature (30°C). However, these results were of relative nature, and did not mean that decomposition of a component was completely stopped at a high or a moderate temperature. It can be therefore assumed as justifiable that there is no need for special control of the temperature for the fermentation. On the other hand, a high temperature has another benefit besides the fermentation, i. e. destruction of contaminating weed seeds and noxious microbes can be attained with a high temperature. It is therefore to be duly considered to allow the composting material pass through a range of high temperature.
2) Three different methods were adopted for fermentation, i. e. intact keeping, keeping with turning-up and forcible aeration, and quality of compost produced by the three methods was compared with each other, but no essential difference was found out in it.
On the basis of analysis of the quality, decomposition of hemicellulose was slightly less in the group with aeration than in the other two groups, while the results of the group with forcible aeration tended to be more favorable in conjunction with germing test of seeds. The causes for these findings will have to be further investigated in connection with the completion of composting.
3) As rice hulls as the moisture-adjusting material have more favorable shapes for bringing air into compost and for facilitating aeration after piling-up, it is rather more desirable to use the whole shape of the rice hull than using in crushed form. There was no effect found out by crushing in improving the decomposition. Even with the whole shape, complete decomposition could be attained for example with hemicellulose.
