Changes in Certain Paddy Soil Properties under Perforated Sheet Pipe as Subsurface Shallow Drainage

抄録

Certain soil properties are expected to change under subsurface shallow drainage. This study focuses on the use of sheet pipes originally developed for use in Japan approximately 40 years ago. However, limited research on the said sheet pipes necessitates further study. To investigate the changes in soil properties in a field where a sheet pipe has been installed, soil samples were collected from drainage stream sites in the field—upstream, midstream, and downstream—at specific distances from the sheet pipe (0 m, 1 m, and 2 m) and soil depths (10 cm, 25 cm, and 45 cm), both before and after rice cultivation. In only one rice cropping, we found no significant impact caused by the sheet pipe on some soil properties, except for larger pores. We observed larger mesopores portions (MePs) at distances of 0 m and 1 m from the sheet pipe in deeper soil layers (at depths of 25 cm and 45 cm). Although this study found no significant differences in macropores (MaPs), MePs could lead to the development of MaPs and cracks and could improve drainage characteristics in the future.