New trends in the study of drip irrigation

out of the border, or a ridge which prevents all outflow. Borders may be classified into three types(35)(a) Long border strip along the direction ofthe prev.~ing slope, with protable laterals, fig. Cl -3 ),the long uninterrupted border strip run irrigatedby portable laterals. The land is irrigated by disc-harging the entire pipe flow directly from the end ofthe portable pipe. The pipe is made up here of rela-tively short sections, each having the length of oneor two border strip widths. where the pipe flow hasto be divided between two or more strips at a time,T-pipes with sleeves are inserted at every pipe joint,which are at every second borders. First the lastborder is flooded, then one pipe section after anotheris removed and rolled out again across the borders,wherever required further up or furtherdown the slopeof the next successive setting to continue the irriga-tion. To avoid erosion, the flow from the pipe end ismade to discharge against bucket-like hood.(b) Level borders, fig.(1-4),: This method have becomethe most widely adapted method in many new developmentprojects over the world. The reasons for this trendin development are to prevent erosion which wouldexpose the unfertile subsoil, and to save water. Both