Improvement of Rice Seedling Establishment on Sulfate-Applied Submerged Soil by Seed Coating with Poorly Soluble Molybdenum Compounds

摘要

Although direct seeding is expected to be a labor-saving method in rice cultivation, poor seedling establishment is a major obstacle to widespread use of this practice. I previously reported that the seedling establishment of rice sown on sulfate-applied submerged soil was improved by the application of potassium molybdate to the soil. In this study, I investigated the effects of seed coating with poorly soluble molybdenum compounds on the seedling establishment to reduce the necessary amount of molybdenum (Mo). Seed coating with poorly soluble Mo compounds improved the seedling establishment in sulfate-applied submerged soil. Especially, ammonium phosphomolybdate and potassium phosphomolybdate were more effective and difficult to impair the seedling establishment even by seed coating of excessive amounts. Mo trioxide, which is a cheapest Mo compound, was also effective. Accordingly, seed coating with these Mo compounds would have the potential to improve rice seedling establishment in sulfur-rich submerged soil.