Developmental studies on weed control method by mulching recycled paper.

Research Project

Project/Area Number	05556004
Research Category	Grant-in-Aid for Developmental Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	作物学
Research Institution	Tottori University
Principal Investigator	TSUNO Yukindo Fac.of agri., Tottori Univ. Professor., 農学部, 教授 (00036287)
Co-Investigator(Kenkyū-buntansha)	HANAHARA Hisashi Sanyo Paper Co.Technical Division. Head., 技術部開発課, 主任 YAMAGUCHI Takeshi Fac.of agri., Tottori Univ. Research Assistant., 農学部, 助手 (30182447) NAKANO Junichi Fac.of agri., Tottori Univ. Associate Professor., 農学部, 助教授 (20032641)
Project Period (FY)	1993 – 1994
Project Status	Completed (Fiscal Year 1994)
Budget Amount *help	¥12,900,000 (Direct Cost: ¥12,900,000) Fiscal Year 1994: ¥5,500,000 (Direct Cost: ¥5,500,000) Fiscal Year 1993: ¥7,400,000 (Direct Cost: ¥7,400,000)
Keywords	Recycle paper / Mulching / Rice / Germination / Seedling emergence / Calcium peroxide / Boric acid / Direct sowing / 湛水直播 / 雑草の光合成 / 硝酸マグネシュウム
Research Abstract	The objectives of this study were (1) to promote seedling emergence and establishment on the direct sowing in flooded paddy field, (2) to make clear the characteristics of photosynthesis on main weeds and (3) to pursue the possibility of realization on the direct sowing with mulching recycled paper. (1) We investigated germination and seedling emergence on seeds coated with calcium peroxide (CaO2) adding several chemicals under the conditions of 2 cm sowing depth and 3 cm flooding.When boric acid (H3BO3) and/or magnesium nitrate hexahydrate (Mg (NO3 ) 2) were added 1% to CaO2, percentage of seedling emergence was higher than only CaO2. This efficacy of both chemicals was seemed that H3BO3 sterilized soil around a seeds and Mg (NO3) 2 supplied oxygen and nutriment for seeds. (2) We prepared the light and photosynthesis curves in water of main weeds and examined the illuminance at the respiration rate and amount of photosynthesis became the same (illuminance at the compensation point) . The results was considered that no weed would be able to grow if about 90% of the light was shaded. (3) The most important point in using the paper mulch direct sowing was make sure that the paper and soil stick firmly to each other.For this purpose, it should do soil puddling and leveling work carefully to make soil surface as flat as possible. And the irrigation water should be 1 cm deep or less. This is because pieces of paper will rise to the surface after sowing and shade seedling if the water is too deep. Thus, this will affect their growth adversely.