91丝瓜视频

Land drainage has been shown to provide significant economic and environmental benefits in agricultural crop production. In Canada, 43 million ha of land is currently under arable agricultural production with about 19% of this land under intensive drainage.聽One type of drainage system commonly used is subsurface tile drainage. This drainage system consists primarily of a network of buried pipes, which allows shallow groundwater to enter through openings or perforations on the pipe wall.