副資材に竹チップを利用した堆肥製造の試み

Abstract

Abandoned bamboo forest is expanding and causes the social and environmental problems in Shimane Prefecture. We tried to find the way to utilize the expanding bamboo forest as resources, not as a troublemaker. Producing cow dung compost using bamboo culm chips is one of potential usage of bamboo in collaboration with husbandry in that area. We investigated the compost quality produced with various mixing ratio of fresh bamboo chips as an auxiliary material to cow dung. As results, highest temperature of the mixture of dung and bamboo chip was about 70℃ during the first stage of fermentation. However, aerating operation following the first fermentation resulted lowering temperature during secondary fermentation or later. Lower temperature following the first fermentation suggested that composting processes seemed to end incompletely. Produced compost was served for cultivation experiments with Japanese mustard spinach. These cultivation experiments showed that compost produced with higher proportion of bamboo chip leaded greater biomass of plants, implying the compost with bamboo chip might enhance the growth rate. Our results revealed the bamboo chip has certain potential to replace the rice straws or husks when the chips were used as an auxiliary material to produce the cow dung compost.