Automatic Equipment for Surface Irrigation

Automatic and semi-automatic surface irrigation structures and systems are being developed to improve irrigation water management and conservation on the farm. Most mechanized structures may be classified as fully automatic or semiautomatic depending upon their method of operation. A fully automatic system operates without attention from the operator other than periodic inspections from one irrigation to the next. The need for irrigation and often the irrigation time periods, however, are still largely determined by the irrigator who usually has to turn water into the system. The semi-automatic system uses gates and checks which are normally tripped at a preset time by a mechanical timer or electrically. In addition to determining the need for irrigation, the irrigator also manually resets the structures or moves them from one location to another, or both, prior to each irrigation. With competition for available national water supplies increasing, some irrigation water users may be forced to use their water more efficiently. Automatic equipment provides a means of accomplishing this while at the same time saving labor. At a time when reliable farm help is difficult to obtain, and wage rates are increasing, an investment in automatic structures could be an economical alternative and may be more easily justified than in the past. Surface flooding systems using basins, borders or contour ditches are easiest to automate since the field topography allows the entire stream of water to be distributed over the soil surface. When furrows are used, however, the irrigation stream must be uniformly divided into many small streams directed into individual furrows. This requires furrow flow regulating devices or controls in addition to check and turnout structures