2008 Volume 2008 Issue 255 Pages 277-282,a2
The agglomeration of farm fields and the establishment of large-scale rotation crop systems, involving e. g. paddy rice, soybean, and wheat, is a current requirement for Japanese agriculture. The low-cost, labor-saving cropping technology, a prerequisite for this development, may be hampered by moisture damage or drought. As a promising method to avoid such problems, a sloping subsoil and field surface was made using a laser-controlled plough and leveler for studying the effects of the slope on paddy water drainage and flooding rates, determining an optimum slope, and examining soil loss. The sloping field proved to be effective for accelerating drainage by increasing the drain flow rate. The technology contributes to preventing moisture damage and to reducing irrigation time, which suppresses moisture damage around the water intake. The slope caused no surface erosion. A slope of 1‰ was proper in terms of drain and irrigation facilitator, soil loss, and construction times.