The composting pile (about 400 kg) was prepared constituting of pig manure and rice straw in a ratio of 3:1 (w/w, fresh weight). The initial moisture content of the compost was adjusted to about 65% and maintained at the same level by adding necessary amount of water weekly. Composting was conducted in a vessel with a volume of 640 L (length×width×height=0.8 m×0.8 m×1.0 m). In the button of the vessel, there were eight PVC tubes with ventilation
holes in sidewalls. Forced aeration was used during the composting and the air-blowing was controlled by a timer
which was set at 30 min ventilation per hour. The aeration flow was controlled at 6 m3 h-1 by rotameters. Temperature
was measured daily at the center of the pile by temperature sensors and the ambient temperature was achieved
simultaneously.