Economic Evaluation of New Equipment for Cattle Manure Treatment : A Case of Development of the Mechanical Separator for Semi-solid Manure

Slurry and semi-solid manure exhausted by daily farmers have been spread to the meadows by substitution for fertilizer. However, it is pointed out that the bad smell from the manure and being excessively spread causes environmental pollution. Because it is difficult to compost manure for high moisture, upland farmers cannot increase the amount of use of the manure. The technology that can improve this problem is the mechanical separator. Though the mechanical separator for slurry manure had already been developed, a mechanical separator for semi-solid manure has not yet been finished. Moreover it is expected that semi solid manure will have been exhausted from 19% of the daily farmers in the Tokachi region, and from 72% of the daily farmers who have introduced the free stall daily barn. Therefore, the development and economic evaluation of the mechanical separator for semi-solid manure is in high demand. To develop the mechanical separator for semi-solid manure, we investigated the use of mechanical separators for slurry manure. The obtained solid fraction can be used as compost. Moreover, the obtained liquid fraction can be used as fertilizer, and the expense for fertilizer was greatly decreased. According to a trial calculation for the expenses of the developed mechanical separator for semi solid manure, it turned out to be 5.21 million yen for a dairy farmer with 80 dairy cows. It revealed that the annual expense for use also reaches about 10 percent of overall expenses. The investment in the manure treatment technology won’t increase income immediately. Therefore, it is necessary to judge the possibility of an introduction based on economic evaluation