Growth, Yield and Quality of Soybeans Cultivated with Minimum Tillage and Concurrent Seeding in an Andosol Upland Field Converted from a Paddy Field

Abstract

We examined the practical applicability of the method of minimum tillage and concurrent seeding using a chisel plow (CPS) in a crop rotation system by comparing the seeding work hours, growth, yield, and quality obtained using CPS with that obtained using broadcast cultivation (broadcasting) on an Andosol upland field converted from a paddy field. Seeding work hours was about 10% less than that in broadcasting. The soil pulverization rate was lower in CPS than in broadcasting, but there was no significant difference in the rate of seedling establishment between them. There was no difference in the aboveground dry weight, leaf-area-index (LAI), and leaf color during the period from the flowering stage to the grain-filling stage. The relative solar radiation on the ground surface until the flowering stage was higher in CPS than in broadcasting. There was no significant difference in the number of weeds between broadcasting and CPS, but the individual dry weight of the weed tended to be heavier in CPS. No significant difference was found between broadcasting and CPS in the growth, yield, and quality. These results suggest that CPS in crop rotation systems in paddy fields is a labor-saving cultivation technique suitable for soybeans, as is broadcasting.