近年,美国发明的“双层灌溉排水系统”是在作物地表下埋置两层深度不同的瓦管管道,一层埋在地表下0.5～0.6m 深处作灌溉用,另一层埋在地表下0.9～1.2m 深处作排水用。两层管系各有自己的阀门控制水流,打开排水闸,水从农田土壤中排入集水坑,从集水坑抽入水库。关闭排水闸,打开灌溉闸门,将水库中水抽入灌溉管系向土壤灌溉,通过排水与灌溉循环, In recent years, the United States invented “double irrigated drainage system ” is buried in the crop under the surface of two different depths of tile pipe, one buried in the ground surface of 0.5 ~ 0.6m for irrigation, and the other buried Under the surface of the depth of 0.9 ~ 1.2m for drainage. Each of the two pipelines has its own valve that controls the flow of water, opens the drain, drains water from the farmland into the sump, and sucks into the reservoir from the sump. Close the drainage gate, open the irrigation gate, the reservoir water pumping into the irrigation pipe to the soil irrigation, drainage and irrigation through the cycle,