Drip irrigation, also known as trickle irrigation, consists of a system of small diameter plastic pipes with emitters or drippers that drip water onto the soil at very low rates (2-20 liters/hour). Unlike surface and sprinkler irrigation, which wets the entire soil profile, water is applied close to plants, wetting only the part of the soil where the roots grow. Drip irrigation water is applied more frequently (usually every 1-3 days) than other methods, resulting in a very favorable high moisture level in the soil that allows plants to thrive.