It's a good thing farmers don't need to haul buckets of water to keep crops watered. Nearly as old as the bucket method though, is furrow or flood surface irrigation where farmers flow water down small trenches running through their crops. For more information about irrigation read on.
• Water Science School HOME • Water Use topics •
Probably one of the oldest methods of irrigating fields is surface irrigation (also known as flood or furrow irrigation), where farmers flow water down small trenches running through their crops. Humans' first invention after learning how to grow plants from seeds was probably a bucket. Ancient people must have been strong from having to haul buckets full of water to pour on their first plants. For most of human history, people did not have mechanized spray irrigation systems to apply water to crop fields. It was more like, "Hey, Big Guy, take this reed bucket and go down to the river and fill 'er up."
Surface irrigation is still used today throughout the world,especially in less-developed areas where mechanical techniques are not available. In fact, in the United States in 2000, about 29.4 million acres were irrigated by flood irrigation as compared to about 28.3 million acres irrigated by spray irrigation. Flood irrigation is not the most efficient irrigation method, but it is cheap and low-tech. On the one hand, less water is lost to evaporation than in spray irrigation, but on the other hand, more water can be lost from runoff at the edges of the fields.
Here are some more-efficient surface-irrigation techniques that farmers use:
- Leveling of fields: Flood irrigation uses gravity to transport water, and, since water flows downhill, it will miss a part of the field that is on a hill, even a small hill. Farmers are using leveling equipment, some of which is guided by a laser beam, to scrape a field flat before planting. That allows water to flow evenly throughout the fields. (Actually, this method of levelling a field is also used to build flat tennis courts).
- Surge flooding: Traditional flooding involved just releasing water onto a field. In using surge flooding, water is released at prearranged intervals, which reduces unwanted runoff.
- Capture and reuse of runoff: A large amount of flood-irrigation water is wasted because it runs off the edges and back of the fields. Farmers can capture the runoff in ponds and pump it back up to the front of the field where it is reused for the next cycle of irrigation.
Flood/furrow irrigation water use in the United States, 2015
Irrigation is one of the major uses of water throughout the world. In the United States in year 2015, irrigation withdrawals were an estimated 118,000 million gallons per day (Mgal/d), or 132,000 thousand acre-feet per year. About 63,500 thousand acres were irrigated in 2015. Of this total acreage, about 23,300 thousand acres with flood/furrow systems.
Irrigation methods
Below are science topics related to irrigation water use.
Water Use Information by Topic
Evaporation and the Water Cycle
Irrigation: Drip or Microirrigation
Irrigation Methods: A Quick Look
Irrigation Water Use
Below are multimedia resources related to irrigation water use.
Below are publications related to irrigation water use.
Estimated use of water in the United States in 2015
Estimated use of water in the United States in 2010
- Overview
It's a good thing farmers don't need to haul buckets of water to keep crops watered. Nearly as old as the bucket method though, is furrow or flood surface irrigation where farmers flow water down small trenches running through their crops. For more information about irrigation read on.
• Water Science School HOME • Water Use topics •
Flood irrigation of corn crops in Mississippi. Probably one of the oldest methods of irrigating fields is surface irrigation (also known as flood or furrow irrigation), where farmers flow water down small trenches running through their crops. Humans' first invention after learning how to grow plants from seeds was probably a bucket. Ancient people must have been strong from having to haul buckets full of water to pour on their first plants. For most of human history, people did not have mechanized spray irrigation systems to apply water to crop fields. It was more like, "Hey, Big Guy, take this reed bucket and go down to the river and fill 'er up."
Surface irrigation is still used today throughout the world,especially in less-developed areas where mechanical techniques are not available. In fact, in the United States in 2000, about 29.4 million acres were irrigated by flood irrigation as compared to about 28.3 million acres irrigated by spray irrigation. Flood irrigation is not the most efficient irrigation method, but it is cheap and low-tech. On the one hand, less water is lost to evaporation than in spray irrigation, but on the other hand, more water can be lost from runoff at the edges of the fields.
Here are some more-efficient surface-irrigation techniques that farmers use:
- Leveling of fields: Flood irrigation uses gravity to transport water, and, since water flows downhill, it will miss a part of the field that is on a hill, even a small hill. Farmers are using leveling equipment, some of which is guided by a laser beam, to scrape a field flat before planting. That allows water to flow evenly throughout the fields. (Actually, this method of levelling a field is also used to build flat tennis courts).
- Surge flooding: Traditional flooding involved just releasing water onto a field. In using surge flooding, water is released at prearranged intervals, which reduces unwanted runoff.
- Capture and reuse of runoff: A large amount of flood-irrigation water is wasted because it runs off the edges and back of the fields. Farmers can capture the runoff in ponds and pump it back up to the front of the field where it is reused for the next cycle of irrigation.
Flood/furrow irrigation water use in the United States, 2015
Irrigation is one of the major uses of water throughout the world. In the United States in year 2015, irrigation withdrawals were an estimated 118,000 million gallons per day (Mgal/d), or 132,000 thousand acre-feet per year. About 63,500 thousand acres were irrigated in 2015. Of this total acreage, about 23,300 thousand acres with flood/furrow systems.
Irrigation methods
- Science
Below are science topics related to irrigation water use.
Water Use Information by Topic
Water is everywhere, which is fortunate for all of humanity, as water is essential for life. Even though water is not always available in the needed quantity and quality for all people everywhere, people have learned to get and use water for all of their water needs, from drinking, cleaning, irrigating crops, producing electricity, and for just having fun.Evaporation and the Water Cycle
Evaporation is the process that changes liquid water to gaseous water (water vapor). Water moves from the Earth’s surface to the atmosphere via evaporation.Irrigation: Drip or Microirrigation
In drip irrigation (microirrigation), water is run through pipes (with holes in them) either buried or lying slightly above the ground next to the crops. Water slowly drips onto the crop roots and stems.Irrigation Methods: A Quick Look
Irrigation is the controlled application of water for agricultural purposes through manmade systems to supply water requirements not satisfied by rainfall. Crop irrigation is vital throughout the world in order to provide the world's ever-growing populations with enough food. Many different irrigation methods are used worldwide, includingIrrigation Water Use
Throughout the world, irrigation (water for agriculture, or growing crops) is probably the most important use of water (except for drinking and washing a smelly dog, perhaps). Irrigation water is essential for keeping fruits, vegetables, and grains growing to feed the world's population, and this has been a constant for thousands of years. - Multimedia
Below are multimedia resources related to irrigation water use.
- Publications
Below are publications related to irrigation water use.
Estimated use of water in the United States in 2015
Water use in the United States in 2015 was estimated to be about 322 billion gallons per day (Bgal/d), which was 9 percent less than in 2010. The 2015 estimates put total withdrawals at the lowest level since before 1970, following the same overall trend of decreasing total withdrawals observed from 2005 to 2010. Freshwater withdrawals were 281 Bgal/d, or 87 percent of total withdrawals, and salinAuthorsCheryl A. Dieter, Molly A. Maupin, Rodney R. Caldwell, Melissa A. Harris, Tamara I. Ivahnenko, John K. Lovelace, Nancy L. Barber, Kristin S. LinseyEstimated use of water in the United States in 2010
Water use in the United States in 2010 was estimated to be about 355 billion gallons per day (Bgal/d), which was 13 percent less than in 2005. The 2010 estimates put total withdrawals at the lowest level since before 1970. Freshwater withdrawals were 306 Bgal/d, or 86 percent of total withdrawals, and saline-water withdrawals were 48.3 Bgal/d, or 14 percent of total withdrawals. Fresh surface-wateAuthorsMolly A. Maupin, Joan F. Kenny, Susan S. Hutson, John K. Lovelace, Nancy L. Barber, Kristin S. Linsey