2018 年 62 巻 4 号 p. 196-207
Food waste and sewage sludge are good sources for making organic compost which contain many kinds of plant nutrients and release slowly. To recover the early growth inhibition of rice plants which affected by the application of sewage sludge compost (SSC) and food waste compost (FWC) and to improve rice yield, the pot experiments were conducted with seasonal repetitions for three years. Experimental design was made by combination of the following factors: types of compost (FWC and SSC), different amount (5.5, 11, 16.5 and 22 g Nitrogen per 24 L pot), compost application methods (uniform application and side dressing), and transplanting dates as seasonal repetition (three repetitions in 2015, two in 2016 and one in 2017) and compared with chemical fertilizer treatment and no fertilizer treatment. The depression effects of FWC application on rice growth was more than SSC in all repetitions. The tiller number were most affected than the other growth parameters and root development than other biomass productions. These phenomena were found to be improved and recovered by late transplanting and side dressing of compost under the condition of the same type and amount of compost. Uniform application of compost which is common in rice production, caused inhibition effects at the early growth stage of rice plants. In order to use compost as basal dressing, side dressing was considered to be useful to decrease the inhibition effects of both composts at the early growth stage, especially for FWC. The side dressing of compost also produced more yield than that of uniform application.
