Simultaneous Application of Controlled Availability Fertilizers to Seeding Furrows with Seeding Increases Grain Yield and Quality of No-Till Cultivated Common Wheat in Japan

摘要

In Japan, common wheat is cultivated in upland fields converted from paddy fields, where poor drainage and high precipitation cause delay of sowing, lodging at the jointing stage, difficulty in topdressing at the ripening stage, and low yield. No-till cultivation has been promoted to overcome these problems but the yield is still low due to the lack of proper fertilizer application protocols. In this study, we determined whether an additional application of two kinds of Sigmoid coated urea as controlled availability fertilizers (CAFs) to the standard fertilization protocol for tillage cultivation can increase the yield and lodging resistance in no-till cultivated common wheat. Also, additional fertilization was applied to the seeding furrow simultaneously with seeding using a V-furrow no-till direct sowing (VFDS) machine. No-till cultivated plants had more tillers than tillage cultivated ones and consequently higher number of panicles and yield, caused by increased fertilizer application. The point-injected CAFs to the seeding furrow, which eluted at the jointing and ripening stages greatly increased the grain yield and protein content, respectively, compared to broadcast topdressing of ammonium sulfate at each stage. The simultaneous sowing and fertilization of additional CAFs using VFDS method in multi-year tests in farmers’ fields significantly increased the yield of no-till cultivated common wheat, and can be adopted by Japanese local farmers.