Material cycle of agriculture on Miyakojima Island: Material flow analysis for sugar cane, pasturage and beef cattle

Abstract

Agriculture on Miyakojima Island is highly dependent on imported fertilizer and feed. To reduce this dependence, the present research examines the biomass resources on the island by conducting a material flow analysis of stockbreeding and other related systems. To accurately quantify the amount of available biomass resources, loss ratios of the storage and composting processes are established. Then, a material flow analysis of a composting facility is made. Finally, current material flows between beef cattle, sugar cane and pasturage are shown. Based on this research, two proposals are made: the first is to use urine as liquid fertilizer, which is currently being done in Saga prefecture. The precedent of using urine as fertilizer is now widely accepted in the Saga area; is considered to be readily adoptable in other areas and could be substituted for the imported fertilizers on Miyakojima Island. The second is to use more residues of sugar cane for the beef cattle feed when the pasturage growth is slow in the winter. The present research suggests that the silage feeds for beef cattle.