2026 Volume 88 Issue 3 Pages 178-185
We investigated the working time and estimated the cost of constructing a new underdrain parallel to the long side at 10 m intervals. The field had a length of 100 m on the long side and 30 m on the short side. We used a tractor and a drainpipe retractable implement (underdrain specification) with an operator and an assistant. The results showed that the working time and construction cost (material cost＋labor cost＋depreciation cost) per 10 a were 18.0 min and 39,956 yen when the underdrain pipe was retracted at 0.20 m/s, 14.4 min and 39,516 yen when the pipe was retracted at 0.40 m/s, and 13.0 min and 39,352 yen when the pipe was retracted at 0.60 m/s.
