No abstract

Changes in Some Soil Properties under Installed Sheet Pipe using such drainage technologies (Tiwari & Goel 2017, Schwab et al. 1985. Most studies have focused on topsoil with a heavy texture and the spacing of deep drains and mainly compared adjacent soils with nonmole or tile drainage. Thus, limited literature has explained the long-term effects of such drainage on crop yield and soil physical properties (Wesström et al. 2008).In a deep drainage study, Francis & Morton (1991) not only claimed that subsurface gravel mole drainage did not affect drainage through less surface infiltration and soil water content but also observed more root extension from upper layers to near the drainage. Subsurface shallow drainage is expected to offer more benefits in accelerating drainage compared with deep drainage (Oosterbaan 2017). Therefore, more research must be conducted on subsurface shallow drainage such as sheet pipe.Sheet pipe was developed approximately 40 years ago and is mainly installed in the western part of Japan. Sheet pipe was typically installed at soil depths of 40 cm-50 cm with close spacing (4 m-8 m). These settings have been settled in empirical ways. Compared with JARQ 56 (1), 59-66 (2022) https://www.jircas.go.jp