Abstract
The effects of compost fertilization and pesticide application on the grain yield of an early maturing rice variety were examined for 15 years in the paddy field of Shizuoka University. Husk manure was applied without a pesticide (weeds were removed with a weeder and by hand) in the HMP-F plot from 1996 to 2010. Cattle manure was applied without a pesticide in the CMP-F plot from 1996 to 2010. Both chemical fertilizer and pesticide were applied in the CFP plot from 1996 to 2010. Neither fertilizer nor pesticide was applied in the NFP plot from 1998 to 2010. The rice grain yield during the first five years was 437, 430, 523 and 329 g m-2 respectively in the HMP-F, CMP-F, CFP and NFP plots. The effect of long-term manuring became apparent in CMP-F after the fifth year, and in HMP-F after the seventh year. It was confirmed that the eating quality value measured with a rice analyzer for eating quality tended to be high in the organic cultivation with husk manure or cattle manure compared with the conventional cultivation with a chemical fertilizer. It was clear that the total amount of nitrogen in paddy soil in the organic cultivation is larger than in conventional cultivation with a chemical fertilizer.
