Over this same time period, irrigated cropland acreage in Arkansas increased by more than 1 million acres while Texas saw a decline of nearly 1. In , Arkansas supplanted Texas as the State with the third most irrigated acres behind Nebraska and California. These observed regional trends reflect how changing water availability related to competing water demands, drought effects on surface water supplies and groundwater depletion has influenced the regional distribution of irrigated production.
Irrigation water allocations by crop reflect climate and crop-water consumptive requirements as well as shifting market conditions. Irrigated acres planted in corn and soybeans have expanded in the past 50 years. In , cotton and hay, alfalfa were the leading irrigated crops, with corn and soybeans together accounting for less than 2. In , corn grown for grain accounted for the most irrigated acreage in the U.
Soybeans accounted for the second most irrigated acreage in with more than 9 million irrigated acres harvested. The shift reflects expanding market demand for corn and soybeans as livestock feed and source for biofuel, as well as the broader eastern shift of irrigated agriculture where variable growing season rainfall promotes irrigating corn and soybean crops.
Irrigated agriculture relies on both surface water and groundwater to support crop production. According to the Irrigation and Water Management Survey, more than half of all water applied as irrigation came from surface water with the remaining water obtained from groundwater sources. Surface water-fed irrigation is most common in the western U. In many of the most prominent irrigated agricultural regions of the U. S, on-farm water withdrawals are generally supplied or managed by a local irrigation organization.
Facebook Twitter LinkedIn Syndicate. Irrigation vs. Rain-Fed Agriculture There are two main ways that farmers and ranchers use agricultural water to cultivate crops: Rain-fed farming Irrigation Rain-fed farming is the natural application of water to the soil through direct rainfall. Top of Page Types of Irrigation Systems There are many different types of irrigation systems, depending on how the water is distributed throughout the field.
Some common types of irrigation systems include: Surface irrigation Water is distributed over and across land by gravity, no mechanical pump involved. Healthy Water Sites.
Get Email Updates. To receive updates highlighting our recent work to prevent infectious disease, enter your email address: Email Address. What's this? Links with this icon indicate that you are leaving the CDC website. Estimates vary, but about 70 percent of all the world's freshwater withdrawals go towards irrigation uses 1.
Large-scale farming could not provide food for the world's large populations without the irrigation of crop fields by water gotten from rivers, lakes, reservoirs , and wells. Without irrigation, crops could never be grown in the deserts of California, Israel, or my tomato patch..
Irrigation has been around for as long as humans have been cultivating plants. Man's first invention after he learned how to grow plants from seeds was probably a bucket.
Ancient people must have had strong backs from having to haul buckets full of water to pour on their first plants. Pouring water on fields is still a common irrigation method today—but other, more efficient and mechanized methods are also used.
One of the more popular mechanized methods is the center-pivot irrigation system, which uses moving spray guns or dripping faucet heads on wheeled tubes that pivot around a central source of water. The fields irrigated by these systems are easily seen from the air as green circles.
There are many more irrigation techniques farmers use today, since there is always a need to find more efficient ways to use water for irrigation. When we use water in our home, or when an industry uses water, about 90 percent of the water used is eventually returned to the environment where it replenishes water sources water goes back into a stream or down into the ground and can be used for other purposes. But of the water used for irrigation, only about one-half is reusable.
The rest is lost by evaporation into the air, evapotranspiration from plants, or is lost in transit, by a leaking pipe, for example. Every five years, water withdrawal and use data at the county level are compiled into a national water-use data system, and state-level data are published in a national circular. Access the most recent National, state, and county irrigation data, maps, and diagrams.
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. For the water cycle to work, water has to get from the Earth's surface back up into the skies so it can rain back down and ruin your parade or water your crops or yard.
It is the invisible process of evaporation that changes liquid and frozen water into water-vapor gas, which then floats up into the skies to become clouds. The Nation's surface-water resources—the water in the nation's rivers, streams, creeks, lakes, and reservoirs—are vitally important to our everyday life.
Row crops are typically grown on the ridge or bed between the furrows, spaced from 1 metre apart. These systems divide the paddock into bays, separated by parallel ridges or border checks.
Water flows down the paddock's slope as a sheet guided by ridges. On steeply sloping lands, ridges are more closely spaced and may be curved to follow the contour of the land. These systems differ from traditional border check or flood systems in that slope of the land is level and area's ends are closed.
Water is applied at high volumes to achieve an even, rapid ponding of the desired application depth within basins. A center-pivot sprinkler is a self-propelled system in which a single pipeline supported by a row of mobile towers is suspended 2 to 4 metres above ground. Water is pumped into the central pipe. As the towers rotate slowly around the pivot point, a large circular area is irrigated. Sprinkler nozzles mounted on — or suspended from — the pipeline distribute water under pressure as the pipeline rotates.
The nozzles are graduated small to large so that the faster moving outer circle receives the same amount of water as the slower moving inside. Hand move sprinkler systems are a series of lightweight pipeline sections that are moved manually for successive irrigations.
Hand move systems are not suited to tall-growing field crops due to difficulty in repositioning laterals. Water-supply pipelines are generally fixed usually below the soil surface and sprinkler nozzles are elevated above the surface. Solid-set systems are commonly used in orchards and vineyards for frost protection and crop cooling.
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