Compost from pearl culture waste: Method of composting and effective use

Abstract

Waste from activities associated with pearl culturing has become a cause of environmental deterioration on pearl farms. As part of our researches on reducing the environmental burden of Akoya pearl culturing, we investigated methods of composting pearl culture waste and effectively using this compost. We conducted composting tests using the soft body of Pinctada fucata after pearl harvesting as the main material, supplemented with debris resulting from sessile organisms removed during shell cleaning, and plant materials. We found that it was possible to convert Akoya oyster meat to mature compost in approximately 45 days without desalinization, and it was observed that including the debris of removed sessile organisms improved the aeration of the composting materials and increased the fertilizer components of the mature compost. Moreover, a seedling test showed that the mature oyster meat compost, when used at a rate of 10 g compost/1000 cm3 soil, improved the fresh weight of komatsuna. These results indicated that compost made from discarded oyster meat and the debris of removed sessile organisms can be effectively utilized in agriculture. The compost is also expected to reduce the environmental burden on pearl farms.