Abstract
1. Effects of the straw or compost mulching of rice field being managed as following ways on the growth of weeds and rice yield were investigated. 1). Rice being directry seeded on the ridge ef wheat. (Bakkan Unetate Jikimaki) 2). Rice being directry seeded on flat wheat field. (Bakkan Hiraune Jikimaki) 3). Rice being transplanted on the ridge. (Unetate Ishoku) 4). Riee beihg transplanted in row on the ordinary field. (Namikiue) 2. When 37.5k.g. of wheat straw per are were applied only on the ridges of rice field (1&3), the quantity of weeds reduced to 1/4∼1/5 as compared with unweeded plot, and the rice yield were increaced 5∼9% more than that of commonly weeded. Appliation of compost at the rate of 75∼82.5k.g. also decreased the weeds to 1/2∼1/4, but 3∼7% of the rice yield decreased. 3. 37.5k.g. of wheat straw or 75k.g. of compost per are were applied all over the paddy field (2&anp;4), but they had little effects, which may be due to the soil surface being incompletely coverd in these cases.
