Evaluation of Technology for Avoiding Submergence Damage for Seedling Emergence of Soybean in No-Till Culture

Abstract

The seeding time of soybean inevitably tends to fall in the rainy season especially in Aichi prefecture, Japan. Soybean plants grown with no-till culture often suffer from submergence damage due to rain water stagnated in the rugged field created by farming operation for the previous cropping. The reduction or avoidance of the submergence during the first 5 days after seeding has been found to be the key to stabilize the no-till soybean culture in this region. Therefore we evaluated the impact of a simple drainage system we developed on the seedling emergence and growth, which consists of open ditches parallel with seeding furrows, mole drains crossed with ditches at right angles and cracks under seeding furrow made by the disk colter attached to the Aichi-type no-till seeder. The results showed that this system effectively drained the stagnant water in the vicinity of seeds, and thus the submergence damage was minimized even when there was a heavy rain right after seeding except in the fields where the water permeability was extremely low or the groundwater level was consistently high. The no-till seeding with the Aichi seeder could be a practically useful technology that enables efficient seeding during the rainy season for stabilized seedling emergence when combined with this simple drainage system in the field not extremely low in water permeability.