Effects of Seeding Method and Water Management after Seeding on Yield of Iron-Coated and Direct-Seeded Rice in a Submerged Paddy Field in the Hokuriku Region

Abstract

Yield characteristics of iron-coated and direct-seeded rice in a submerged paddy field were evaluated using different seeding methods and water management after seeding in comparison with those with calcium peroxide-coated seeds in the Hokuriku region. Seeding methods were stripe seeding (57 and 30 seedlings/m²) and hill seeding (17 cm and 24 cm between hills). Water managements were flooding and drainage in the early growth stage. Yield in iron-coated direct-seeding was slightly lower than that in calcium peroxide-coated direct-seeding. Yield in iron-coated direct-seeding with hill seeding (17 cm between hills) was the highest among the iron-coated direct-seeding plots, and there were no significant differences in yield between calcium peroxide-coated and iron-coated direct-seeding. This is probably because the light intercepting structure was better, and dry matter production after heading was larger in the hill seeding than in the stripe seeding. The effect of water management on yield was larger in the drainage plot than in the flooded plot. Probably because resistance to logging was higher in the drainage plot resulting in less lodging and high yielding. These results indicate that hill seeding (17 cm between hills) and drainage after seeding are important for reducing lodging and increasing yield in iron-coated direct-seeding.