Treatment and utilisation of oil palm empty fruit bunch (EFB) by Pleurotus sajor-caju cultivation and vermicomposting

• Main Author: Yahaya, Ahmad Naim Ahmad
• Published: University of Sheffield 2012
• Subjects: 633.851
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.575449

The oil palm industry in Malaysia is striving to show that it uses a sustainable approach in order to be accepted internationally and ensure palm oil remains a major commodity in Malaysia. The Malaysian government has already prohibited the burning of oil palm wastes leaving a problem of waste disposal. In this work the cultivation of edible mushroom (Pleura/us sajor-caju) on unsterile oil palm waste empty fruit bunch (EFB) followed by vermicomposting by Eisenia fetida and Dendrobaena veneta is investigated as a sustainable approach to dealing with a major component of the waste. Two stages of treatment are required due to the lignin content, the C:N ratio (54: 1), the high level of total phenolic compounds (31.10 g GAE/1OOg extract, of which 1.35 mg/kg is phenol) and low phosphorous, and potassium in EFB which makes this material resistant to natural degradation (and hence unsuitable for standard composting) and hazardous to earthworms. Biological efficiency (BE) for the production of the edible fungal fruiting body (oyster mushroom) was more than 20% and an indication that the commercial bioconversion of EFB to mushroom is feasible. Thermogravimetric analysis (TGA) showed degradation of hemicellulose, cellulose and lignin and reduction of total phenolic compounds. No trace of phenol was found in extracts of EFB after fungal growth (GC-MS analysis). Treated EFB (i.e. after fungal growth) was found to be suitable for vermicornposting. The nutrient contents (TKN, P, N, Ca, Mg, Na and K) of the vermicornpost compared favourably with commercial high and low organic content compost. The final C:N ratio of the vermicompost was approximately 17: 1. This is an indication of stabilisation of the vermicompost and its suitability as a growth medium and soil enhancer. ICP-MS analysis showed that potentially toxic elements (Cr, Cu, Ni, Pb and Zn) of vermicomposted EFB were below the BSI:PAS:lOO:2011 limits. Seedling germination tests shows fast germination of tomatos, peppers and broad beans in a mixture (50%:50%) of vermicomposted EFB and low organic content compost. However seedling germination in vermicomposted EFB without additional compost was slow. It was concluded that oil palm waste (EFB) can be treated by a combination of Pisajor-caju cultivation and vermicomposting. Edible mushrooms can add to the economic balance of the treatment process and the ability to use unsterilised EFB will reduce costs. The final vermicomposted EFB also gives extra economic value and a beneficial return to the environment as a natural soil treatment material