Abstract
The study area was abandoned about 20 years ago in Nose. Three varieties of rice 'Kinuhikari', 'Asamurasaki' and 'Akamochi' were cultivated in this abandoned terraced paddy fields without chemical fertilizer. For comparison the same variety of rice were cultivated in ordinal paddy field of Sakai with chemical fertilizer. Panicle length, culm length and 1000-grain weight of all variety in Nose were lower than Sakai. Panicle number and ripened filling of 'Kinuhikari' and 'Akamochi' in Nose, however, were higher than Sakai. The yield of 'Kinuhikari' in Nose was slightly lower, but was not significantly different each other, and Akamochi's yield in Nose increased more than 10% of Sakai. Solar radiation and temperature in Nose were lower than Sakai. These atmospheric conditions caused delay heading and higher ripened filling. These results suggest that abandoned paddy fields are capable to cultivate rice without chemical fertilizer.
