Effects of an Ice Plate Formed by Inundation before the Continuous Snow Cover on Surface Soil Water after Disappearance of the Snow Cover at a Rotational Paddy in a Snowy Cold Region in the Period from Autumn of 2007 to Spring of 2008

Abstract

When melt water remains on the soil surface for a long time in rotational paddies in Hokkaido, a snowy cold region of Japan, machine work in the early spring is delayed, resulting in growth delay of crops and decrease in income. Ice plates can be made in paddies in Hokkaido by filling the paddies with water before the continuous snow cover, and melt water flows from the edges of the ice plate. It is expected that the surface soil water after disappearance of the snow cover can be reduced if melt water can flow to an underdrain through open channels along the levees in the paddy. In this study, the effects of an ice plate formed by inundation before the continuous snow cover on surface soil water after disappearance of the snow cover at a rotational paddy in the period from autumn of 2007 to spring of 2008 were examined. It was found that the volumetric water content in the ice plate area was lower than that in the conventional area after disappearance of the snow cover.