Abstract
Although seedling emergence and establishment is inhibited by soil reduction in the direct sowing of paddy rice into puddled and leveled soil, the reasons for this are not clearly understood. This experiment was carried out to clarify whether substances produced in reductive flooded paddy soil could be inimical to seedling emergence and establishment of paddy rice seed sown into flooded soil. As typical substances produced in reductive soil, sulfide, acetic acid, and ferrous iron were added to flooded soil before sowing. Seedling emergence and establishment was poor when the amount of addition was large in all substances. Thus, it seemed that substances produced in reductive soil could be one of the direct causes of seedling emergence and establishment inhibition. Ferrous iron seemed to be the most harmful among the substances tested. But inhibition of seedling emergence and establishment by the substances was attenuated when the seeds were coated with calcium peroxide.
