APPLICATION OF SEWAGE SLUDGE FERTILIZER AND SPENT MUSHROOM (AGARICUS BISPORUS) SUBSTRATE ON TEA (CAMELLIA SINENSIS) CULTIVATION

Abstract

 In this study, to evaluate the possibility of sewage sludge fertilizer and spent mushroom (Agaricus bisporus) substrate application on tea (Camellia sinensis) cultivation, we performed tea cultivation experiments using those materials for 3 years. The yields of tea in the test areas of sewage sludge fertilizer fertilization with spent mushroom substrate were higher than conventional fertilization area (100% of rapeseed wastes with spent mushroom substrate or humus). In particular, test area of sewage sludge fertilizer (50%) and rapeseed waste (50%) fertilization showed the highest yield in this study. Besides, the heavy metals in the sewage sludge fertilizer did not significantly accumulate into the tea leaves. Furthermore, we found that the spent mushroom substrate can be used as soil conditioner for tea cultivation because there was no negative effect of the material compared with conventional soil conditioner (humus). Overall, we found that application of sewage sludge fertilizer at 12 kgN/10a/year could reduce 15% of fertilizer cost compared with conventional fertilizer design, and 88.5% of sewage sludge cake produced in the Kirishima city, Kagoshima, Japan can be utilized in the regional tea cultivation areas.