Submitted to: ARS Instituto Nacional de Investigacones Forestales Agricolas y Pecuarias
Publication Type: Proceedings
Publication Acceptance Date: November 6, 2001
Publication Date: November 6, 2001
Interpretive Summary: The world's population is exponentially expanding while developed water resources are practically constant. In the future, improved efficiency in the use of water for food production will become even more important. This will be true even for the United States as well as Mexico. Irrigated lands have not expanded much, while a much greater proportion of the U.S. crop value is produced from irrigated lands. Limited techniques are available for increasing the efficiency of water use in irrigated agriculture. Reducing water application and conveyance losses are typically minimized to achieve improved crop water use. Often switching to more water efficient crops (sorghum for example) can improve field water use of less productive crops (like wheat). The paper describes advanced irrigation techniques (application techniques, automation, cropping systems, irrigation scheduling, and soil water measurement technologies) that can improve water ruse efficiency along with remote sensing technologies that can better estimate crop water needs over larger landscape segments.
Technical Abstract: The world's population now exceeds six billion people and is increasing at about 80 to 85 million people each year. Irrigated lands previously expanded to keep pace with this population, but future irrigation expansion is not expected to keep pace with future population growth. North American irrigated lands are barely 10% of the world's irrigated lands. In the United States, the 15% of the land that is irrigated produces over 50% of the crop value. Although only 7% of the world's population now lives in water scarce areas, by 2050 nearly 67% of the world's population is expected to live in water scarce areas. Improved water use efficiency is possible by reducing application losses and enhancing use of precipitation. Advanced irrigation technologies (sprinkler or microirrigation) can reduce application losses together with irrigation automation, irrigation scheduling, cropping system sequences, improved evapotranspiration methods and soil water measurement methods and remote sensing to estimate crop water use across larger landscape elements.