Seedling Emergence Performance under Various Tillage Treatments Using Vertical Position Control System Installed on Seeder

摘要

Initial tests on the application of zero tillage crop cultivation in Hokkaido, Japan using a conventional tillage seeder resulted in lesser seedling emergence and crop yields due to higher soil strengths that affected proper seed placement. Thus, the objective of this study was the development and evaluation of a seed depth position control system for the conventional tillage seeder to improve seed placement and increase seedling emergence during zero tillage cultivation. A four-row vacuum seed seeder commonly used in Japan was modified, tested and evaluated. One of the four seeder units was modified and fitted with precision sensors and a hydraulic-based position control system to automatically place the seeds in the soil at the proper seeding depth based on the soil surface profile. Four tillage treatments were tested: conventional tillage (CT), artificial reduced tillage (ART), reduced tillage (RT), and zero tillage (ZT). Both soybean and sugar beet crops were cultivated with similar crop management conditions. Seedling emergence count between the controlled seeder unit row and the uncontrolled seeder unit rows were compared. Highly significant differences (p＜0.01) in seedling emergence were observed between the controlled and uncontrolled seeder unit rows in the treatments with soil strengths ranging from 0.6 MPa to 1 MPa. In this study, the converted seeder successfully increased seedling emergence count. The new system may help encourage local farmers to apply alternative tillage methods for cultivation in the region without sacrificing crop yields.