2013 年 6 巻 4 号 p. 184-190
To improve planosol soil conditions, a new Three-stage Subsoil Interval Mixing Plough (hereafter, TSIM-plough) was developed in 2010. The TSIM-plough resolved three problems encountered by the original Three-stage Subsoil Mixing Plough (hereafter, TSM-plough) developed in 1996. That is addition of an extra first plough body to the previous design TSM-plough. Firstly, its working width was increased from 460 mm to 920 mm with an extra first plough body installed. Secondly, its calculated draught moment caused on the tractor was reduced, thus allowing the tractor to running straight more easily. Thirdly, the ground trafficability increased with the improved layering of soft and hard subsoil solum, and tractors for harvesting no longer sank under wet field conditions even in the first year of operation.