【Paper】

Method of Compost Quality Evaluation Using a Bbioassay Test with Hypha（Pleurotus ostreatus）

Mami Okamoto*, Akira Ikeda** and Akikuni Ushikubo*
* Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture
** Graduate School of Agriculture, Tokyo University of Agriculture
† Correspondence should be addressed to Mami Okamoto:
Faculty of International Agriculture and Food Studies, Tokyo University of Agriculture
（1-1-1 Sakuraoka, Setagaya-ku, Tokyo, 156-8502 Japan）


Abstract
Composting is low cost and environmentally friendly, making this practice an important component of integrated and sustainable waste management systems. Properly aged compost that is sanitized and stabilized can benefit plant growth and the environment, but immature composts can impair plant growth and degrade the quality of the soil. Because of the wide variety of organic wastes, a standard reliable quantitative method has not been developed to evaluate compost quality. This is one reason that recycling of organic wastes has not become more widespread. Therefore, a test is needed to monitor the degree of decomposition of heterogeneous organic materials, including food products, animal manures, and plant residues.
A bioassay test with hypha（Pleurotus ostreatus）was developed as a method of compost quality evaluation to solve this problem. This method measures the growth speed of hypha on culture mediums containing compost after different numbers of days of fermentation, and the quality of compost is evaluated by the difference of the growth speed of hypha. The results were compared with other tests such as the germination index and the analyzed growth inhibitor. This research suggests that the compost quality evaluation bioassay test using hypha growth response is more sensitive than the other tests are.


Key words: Pleurotus ostreatus, compost, organic wastes, quality evaluation, growth inhibitor