Irrigation is the process of applying additional water, above what is supplied by precipitation, to crops of landscape plants in order to promote growth and production. Farmers and gardeners have practiced irrigation since biblical times although the methods and equipment have changed over years. There are three principal types of irrigation systems.
Surface or Flood Irrigation
The simplest form of irrigation requiring the least amount of equipment is surface irrigation in this type of irrigation the field or garden is flooded with water. The water may be contained in furrows within the field or allowed to flow across the entire field and be contained by low dikes or levees around the perimeter. The fields are flooded and then the flow of water is stopped and the water is allowed to soak into the ground. The water commonly flows into the field by gravity from reservoirs at higher elevation levels. Surface irrigation requires higher water volumes than other forms of irrigation.
Drip irrigation uses small plastic hoses and low-flow valves called emitters to provide water directly to the root area of the plant. Drip irrigation commonly provides water for one or two plants from each emitter. The system requires more equipment with a hose for each row of plants and emitters for every plant or two. This usually makes drip irrigation the most expensive for equipment costs. The process requires the highest level of labor to place all of the tubing and emitters. However, the water usage is the lowest of the irrigation methods.
Sprinkler systems use pump-created water pressure to spray drops of water through the air where they fall to the ground. This process most closely mimics natural rain. Sprinkler systems can be large center-pivot irrigation systems that can spray water over more than 100 acres to lawn sprinklers that water a few square feet. Sprinklers fall in the middle as far as water usage between flood and drip irrigation. Cost of equipment varies widely depending on the equipment size and complexity.
The simplest form of irrigation is a gardener with a water can. Other small-scale watering systems include soaker hoses, hoses made of porous materials that leak water where they’re placed, or hand-held sprayers attached to garden hoses.