Direct-seeding of rice (Oryza sativa L.) on Y-shaped furrow without tillage and covering soil in poorly drained paddy soil

Direct - seeding culture without tillage and covering soil using the Y-shap ed seeding furrow was examined in 1997 and 1998 at a poorly drained paddy f ield in Hachirogata (Akita Pref., Japan). The percentage of seedling establ ishment in the plots of polyolefin coated urea (CU) and sigmoid type of CU (SCU) were 50.3% and 44.7%, respectively, in 1997, and 35. 7% and 35.3%, re spectively, in 1998. The cumulative effective temperature from seeding to t he establishment time was 147. 6 degreesC and 124.0 degreesC in 1997 and 19 98, respectively. The number of established seedling per m(2) in the CU and SCU plots was 167 and 149, respectively, in 1997, and 119 and 118, respect ively, in 1998. The brown grain yield per m2 in CU and SCU plots was 645 g and 621 g in 1997, and were 501 g and 472 g, respectively, in 1998. These r esults suggested that the direct seeding of rice on Y-shaped furrow without tillage and covering soil is highly feasible to keep the same level of the yield in the transplanted cultivation of rice in cool and clayey paddy fie lds in the Tohoku District.