Abstract

wastes as biofertilizers. Fresh fish waste (FFW) and cooked fish waste (CFW) mixed with sawdust from Tryplochyton scleroxylon wood species (Wawa) were made into compost heaps. Control compost from rice bran (CRB) was also prepared. Higher temperatures were recorded from compost heaps prepared from both FFW (38 -52°C) and CFW (37 - 52°C) than from CRB (33 - 45°C); with reduction in composting time and generation of large numbers of microorganisms in the fish-based compost heaps. Mycelial colonization of compost bags and subsequent growth of oyster mushrooms (Pleurotus species) were faster in fish-based substrates (FFW and CFW) as compared to CRB. P. eous and P. oestreatus exhibited uniform spread of mycelia in the compost bags than P. eoushybrid. However, P. eous hybrid produced the fastest rate of mycelial growth, completely colonizing the substrate within 26 days. Growth of each species of mushroom investigated was independent of the substrate in which it was grown. Irrespective of the substrate used to grow the mushroom, the pattern of utilization and growth remained the same. Oyster mushrooms grown on fish-based substrates produced bigger and firmer fruiting bodies. This alternative could be very attractive to small farmers throughout the world, who are known to operate under adverse conditions and limited resources.

Key words: Fish waste, organic fertilizer, slow release nitrogen, oyster mushroom,  Pleurotus species.