Abstract
Vegetable cover (rice plant) itself plays an important role of mulch by intercepting the solar energy to the soil surface to dampen soil temperature fluctuations and preventing evaporation from the free water surface of irrigation in paddy field. Mulch in itself is artificial, but the self-mulching action of rice plant arises inevitably in proportion to plant growth. So that the self-mulching action can not be removed even if it is unnecessary to the normal growth. Therefore the plant is compelled to grow under the environmental conditions that were characterized by the self-mulching action whether plant will need it or not.
The author examined the effects of the self-mulch on plant growth and its yield to clear up the facts that the plant height and the number of available tillers were characterized partially by the self-mulch and the development of root system was also characterized by this in part. After all, the yield of rice plant depends partially on the self-mulching action. So these results suggest that the utilization of the unavoidable self-mulching action must be taken into account positively in improving rice cultivation.
