(1) During the Edo period, a rice plant of the Indica-type known as Tomomi rice was being directly seeded into some of the submerged fields in the Shimousa district. (2)The process of direct seeding in submerged paddies was known at the time as "Tumita." (3) Although referred to as Taito-tuchi, the soil of the paddy fields in which Tomomi rice was cultivated was peat soil. (4) The submerged fields composed of peat soil were subject to considerably deoxidized conditions. (5) The cultivation of Japonica-type paddies in Taito-tuchi paddy fields was considerably inhibited. However, Toumomi rice was characterized by the ability to grow even under deoxidized conditions. (6) Generally speaking, while the roots of paddy rice plants grow in all directions when cultivation is conducted by the setting of seedlings, they spread out at the surface when cultivation is conducted by direct seeding. The method of direct seeding in submerged paddies was a type of cultivation that took advantage of the special cultivation property marked by the spreading of roots over an oxidized surface. (7) Based thereon, it can be said that the type of cultivation involving direct seeding in submerged paddies was suitable for generating the large quantities of Tomomi rice by tillers. (8) The cultivation of Tomomi rice by direct seeding was a rational cultivation method conforming to the conditions to be found in unfavorable locations. (9) Consistent with what the above findings indicate, the approaches to the cultivation of paddy rice in the Shimousa district during the Edo period differed in accordance with the conditions of location as can be seen by noting that Tomomi rice was cultivated by direct seeding in Taito-tuchi paddy fields, whereas rice plants of the Japonica-type were cultivated by the setting of seedlings in paddy fields possessing slightly more favorable conditions
