An Implement for Direct-Sown Onion Cultivation that Ridges, Forms Furrows on Ridges, Sows at the Bottom of Furrows and Localizes Application of Fertilizers below Seeds

<p>We developed an implement that ridges, forms small furrows on ridges, localizes application of fertilizers at the bottom of furrows and sows above fertilizers. Effects of the mounting position of the soil-covering plates on soil thickness　covering fertilizers and seeds was investigated. The working speed upper limit was investigated. We investigated the effect of seedling emergence rate, growth rate and yield of autumn-direct-sown onion with or without furrow and phosphate fertilizer. Characteristics of the implement were that the furrow-forming unit was mounted below the top board of the ridging unit, the side walls of the furrow-forming unit were extended toward the sowing unit. Fertilizers and seeds were dropped at the furrow-forming unit and were covered with soil that made by shaving the side walls of furrows using the soil-covering plates. In the soil-covering plates settings tests, the soil-covering plate for seeds had room for improvement, but it was possible to control soil thickness covering fertilizers and seeds that the mounting position of the soil-covering plate for fertilizers was adjusted. In working speed tests, seeds were pushed to the side of the furrow for higher working speed, it was hard to ridge at working speed of over 1.2 km/h. As the result of growing test, seedling emergence of sowing at furrows on the ridges tended to be earlier than the case of sowing on the ridges. Growth rate and yield of sowing at furrows on the ridges in addition to localizing application of fertilizer below seeds were increased compared to the case of sowing at furrows on the ridges and the case of sowing at the ridges.</p>