EFFECTS OF USED-PAPER MULCHING ON GROWTH OF EARLY-SEASON CULTURE RICE

The purpose of this study was to iind practical-use methods of untappe d resources, especially used-paper; which have been collected through recycling systems as organic materials in agriculture. The effects of used-paper mulching were studied on the growth and yield characteristi cs of early-season culture rice, cv. Koshihikari, in the southern part of Kyushu. The experiments were carried out at the University Experim ental Farm, Miyazaki University in 1995 and 1996. Used-paper mulching treatment lowered soil temperature during the daytime and raised it sl ightly at night in the early vegetative growth stage. Since the vegeta tive growth stage was prolonged by the mulching treatment, heading tim e and maturing time were delayed. Mulching treatment had much the same or higher grain yield than usual cultivation methods at the farm, and was effective in the control of competition with weeds. The higher gr ain yield was due to the increase of productive tillers and number of grains per head. Weeds were controlled effectively by the mulching tre atment. It seemed very effective to use paper mulching collectively wi th herbicide in the early stage to control all kinds of weeds in the p addy held. It was estimated that the loss of soil nitrogen from the su rface of paddy field was reduced by the mulching treatment. We conclud ed that mulching the surface of a Daddy field with used-paper is very effective to obtain a high yield and reduce the usage of chemicals in paddy field cropping.