Submitted to: American Society of Agronomy Monograph Series
Publication Type: Book / Chapter
Publication Acceptance Date: 11/21/2005
Publication Date: 5/15/2007
Citation: Trout, T.J., Kincaid, D.C. 2007. On farm system design and operation and land management. In: Lascano, R.J. and R.E. Sojka (eds), Irrigation of Agricultural Crops, Am. Soc. of Agronomy Monograph #30, 2nd Ed. American Society of Agronomy, Madison, WI, pp 133-180.
Interpretive Summary: Agricultural crops are irrigated by several methods. Surface irrigation is the most widely used method worldwide. Surface irrigation uses gravity flow over the soil surface to spread the water. Because of soil variability and uneven surfaces, surface irrigation is difficult to manage and may be inefficient. Sprinkler irrigation is now the predominant method in the U.S. Sprinkler irrigation uses pumps to pressurize water, distribute it through pipeline systems, and spray it across the field surface. Micro-irrigation use is small worldwide, but is growing rapidly in areas of the U.S. where horticultural crops are grown. Micro-irrigation systems use plastic pipe and hoses to distribute water near individual plants where it is slowly dripped or sprayed on or into the soil. Sprinkler and micro-irrigation are more expensive to purchase than surface irrigation, but allow more precise water application.
Technical Abstract: Irrigation water is applied to agricultural crops by many different methods. Irrigation methods can be divided into three broad categories - surface, sprinkler, and micro-irrigation. Surface irrigation systems depend on gravity to spread the water across the surface of the land. Surface systems are also referred to as gravity or flood irrigation systems. The shape of the soil surface and how the water is directed across the surface determine the types of surface systems (i.e. furrow, border, or basin). Sprinkler systems mimic rainfall by spraying the water across the soil surface. The water is pressurized with a pump, distributed to areas of the fields through pipes or hoses, and sprayed across the soil surface with nozzles or sprayers. Types of sprinkler systems depend on the layout of the distribution pipelines and the way they are moved (i.e. solid set, hand move, center pivot, or rain gun). Micro-irrigation systems, also called drip or trickle systems, use small tubing to deliver water to individual plants or groups of plants. These systems use regularly spaced emitters on or in the tubing to drip or spray water onto or into the soil. Micro-irrigation systems are categorized by the placement and type of emitters (i.e. drip or microspray). Surface irrigation remains the most common type of system world wide and is used on nearly 90% of the irrigated land (FAO, 2005). It is the predominant method in Asia which has over 70% of the world’s irrigated land. Sprinkler irrigation is widely used in the U.S. and Eastern Europe. Micro-irrigation systems, although used on only 1% of the world’s irrigated land and less than 6% of the irrigated land in any region, irrigate many high value horticultural crops. In the U.S., where about 20 million hectares of land is irrigated, 44% uses surface irrigation, 51%, sprinkler irrigation, and 5%, micro-irrigation (NASS, 2003). Sprinkler and micro-irrigation use are increasing in the U.S. In this chapter, we describe the many types of irrigation systems within these three basic categories. We briefly discuss system selection and describe design procedures and management requirements. Finally, we describe the adaptability of each system to various crop, soil topographic and socio-economic conditions.