Increase in Breeding Numbers in Dairy Farming and Utilization of Residual Liquid for Fertilizer, in a Biogas System Plant in the Hokkaido Tokachi Upland Areas

Abstract

Dairy farms must dispose of animal waste from their livestock. Generally, it is eventually disposed of on farmland by spraying in the form of compost or slurry. In Japan, dairy farms have increased the number of cows, and free-stall barn has become common. Using a free-stall barn, animal waste is discharged as slurry. A biogas system that uses slurry to generate electricity by methane fermentation is an effective method for disposing the slurry. When using a biogas system, digested slurry remains. The Hokkaido Tokachi region is said to have large scale upland farms; furthermore, some dairy farms also exist in the area. We examine the actual conditions regarding the increase in breeding numbers in dairy farming and the use of digested slurry as a fertilizer, especially for cultivating upland crops, through a use of a biogas system plant in the area.