抄録
Farmers must manage paddy fields for maximum reduction in the water volume that remains after surface drainage. Using computer simulation, we compared two methods for accomplishing this purpose: moving the soil to reduce the altitude on the outlet side and creating an open-ditch drainage. We found that 1) lowering the outlet side reduced the remaining water volume, 2) creating an open-ditch drainage further reduced the water volume, and 3) the effects of these methods depended on the direction of surface roughness of the paddy field.
