14.2: History and Impact

Whereas surface irrigation by gravity began about 8,000 years ago, microirrigation is a relatively new concept. In 1913, E.B. House, at Colorado State University, experimented with subsurface trickle irrigation without raising the water table in the process, but concluded that it was too expensive. With the development of plastics during and following World War II, the idea of using plastic for irrigation pipe became plausible. The discovery of low-density polyethylene pipe in 1948 provided a suitable, economical material for drip irrigation. In the mid-1950s, an irrigation manufacturing firm in New York began supplying polyethylene tubing to water plants in greenhouses.

Publications on modern day trickle irrigation systems began to appear in Israel and the United States in the 1960s. Sterling Davis, working in California, installed the first field experiment with a subsurface trickle irrigation system in a lemon orchard in 1963. From 1968 into the 1970s, numerous inventors and companies developed drip irrigation emitters. By the mid-1970s more than 250 different water application devices had been produced.

In 1977, the plastic industry introduced linear, low-density polyethylene. This new plastic was less expensive, had improved strength, was resistant to stress cracking, and was flexible. With the addition of appropriate additives, such as carbon black, antioxidants, and stabilizers, clear plastic could be converted into a black, durable and economical pipe, well suited for microirrigation.

The first survey of microirrigation in the U.S. in 1974 (Irrigation Journal, 1974) reported about 70,000 acres of microirrigation. California had more than half of the national total (41,000 acres). Besides California, only Arizona, Florida, Hawaii, and Texas, had more than 1,000 acres of microirrigation at that time. By 1990 microirrigation had increased to 1.5 million acres. In the 2000 irrigation survey (Irrigation Journal, 2001), California still accounted for more than half of the 3.1 million acres of micro-irrigation in the U.S., but 40 states had at least 1,000 acres.

In 2018, nearly 56 million acres were irrigated in the U.S. (USDA, 2019). Of this total, microirrigation was used on nearly 6 million acres. Nearly 3 million acres were irrigated with surface drip; subsurface drip systems were installed on just over 1 million acres; and 1.5 million acres were irrigated by low-flow micro-sprinklers. Microirrigation was used on over 4 million acres in California. Fourteen other states had microirrigation on over 20,000 acres.

Although microirrigation accounts for less than 11% of the irrigated land in the United States, it is used frequently on high-value crops and for landscaping. The list of microirrigated crops include tree crops of avocado, citrus, stone fruit, nut, olive, coffee, and mango; and row crops like cotton, grape, melon, pineapple, sugar cane, tomato, and strawberry.

A global survey (FAO, 2021) indicates that in 2017, 20 countries had at least 1 million acres of microirrigation. The total area under microirrigation in these countries is about 25 million acres. Countries where the area of microirrigation exceeds that of sprinkler irrigation include Brazil, Chile, Cyprus, Egypt, Iran, Israel, Morocco, Palestine, Peru, Philippines, Poland, Portugal, Tunisia, and Uruguay. Microirrigation in Israel, for example, expanded from 25,000 acres in 1975 to about 400,000 acres in recent years. Estimates in 1991 indicated that microirrigation was used on 70% of the irrigated land in Israel (Stanhill, 1992).