Rice direct seeding method with recycled-paper mulching

Abstract

We developed a new direct hill seeding method, paper-mulched direct seeding (PMDS). In this method, recycled-paper sheets with rice ( Oryza Saliva L.) seeds affixed are spread over a flooded paddy field just after puddling and leveling. Three or five rice seeds were sandwiched between biodegradable gauze or non-woven mesh, fixed to a hole (25 mm diameter) arranged on the sheet at a distance corresponding to the planting density. The sheet gave a very high percentage (98.3%) of germination in water culture of cultivar, Koshihikari. Koshihikari sown by the PMDS method showed a relatively high percentage of seedling establishment, ranging from 70 to 80%. Moreover, a high stability of seedling establishment was obtained by the PMDS method as compared with lowland hill seeding of non-germinated seeds without use of the oxygen supplying chemical, calcium peroxide. Frequencies of vacant hills in the PMDS plot of 5 cultivars, Akitakomachi, Dontokoi, Hinohikari, Hitomebore and Koshihikari, were very low, ranging from 0.40 to 2.33%. Although no herbicide was applied in the PMDS plot, only a few weeds, i.e., Scripus juncoides Roxb. var. ohwians T. koyama and Eleocharis kuroguwai Ohwi were observed, indicating that herbicides are not required in the PMDS. Little lodging was seen in the PMDS plot. The brown rice yield by the PMDS was 615 g m~z. These results clearly demonstrate that the PMDS is useful for hill seeding in flooded paddy fields.