Abstract
A puddling seeder with a paddy harrow, two fertilizer applicators as seeding units, and a roller was developed to realize direct seeding of pregerminated rice seeds in the cool region in Japan. To determine the appropreate number of puddling and seeding pattern, we investigated the effects of puddling frequency and seeding pattern that is puddling once or twice, and seeding in thick rows or broadcasting, respectively, on seedling establishment and yield from 2010 to 2013 in Daisen, Akita, Japan. Seedling length and number of leaves were higher in puddling twice than in puddling once, while maximum stem number, lodging, dry weight at heading and maturity, and yield were not affected by the number of puddling. Because higher leaf number in an early stage is an advantage in weed control, the twice puddling was adopted for the further studies. Early growth, maximum stem number, lodging, dry weight at heading and maturity, and yield were not affected by the seeding patterns. Broadcasting was adopted for the further studies because the mechanism of the seeder was simple and vegetation rate higher.
