Because agriculture is responsible for most of the water use in the United States, and because irrigation dams are the most widely used water supply dam, it is important to examine how this industry uses water and what methods can be used to increase efficiency and thereby reduce demand for dams. Aside from alternative diversion techniques to provide water for irrigation, the US Environmental Protection Agency has divided irrigation techniques into three categories:
- field practice
- management strategies
- system changes
When these practices are combined with the alternative diversion technique, the demand for diversion dams for irrigation could be eliminated in some cases.
Field practice
Field practices are techniques aimed at retaining water in the field, distributing it, being more capable, or providing better soil moisture retention. These techniques are usually not too expensive as management strategies or system modifications. If traditonal field practices fall short of expectations and the management straegies and system modifications discussed below are out of reach, the field practice of dry-land farming and land retirement is another avenue to explore. Examples of field practices include:
- The chisels extremely compacted soils
- Furrow dikes to prevent runoff
- Land leveling for a water supply
- Trochene country and economy
- country retirement
The miners can develop land management so that the demand for water decreases. More than half of the irrigation area used for agriculture is still eroded by a gravity system. This system uses ground boundaries, furrows, or ditches to allow gravity to deposit water everywhere. Gravity flow irrigation methods can lose up to 50 percent water through, exhaust steam, no water releasing to the crop-stem zone and the runoff to the end of the field. The traditional gravity system can be augmented with the use of laser trimming or micro irrigation, because exhaust steam is still losing water. Laser leveling involves grading and accurately leveling the ground to eliminate the slope and hand of the field. It controls the flow of water, allowing more unity. Another method to prevent the run-off election from happening is furrow diking. Furche dyke is the practice of building small temporary deices over furrows to obtain water for crop production, which also aids in avoiding erosion.
If the above-mentioned land management is not enough water use, and the system changes described below, even if the cost is not prohibitive, or a suitable technique for a particular crop, farmers can also consider switching to soil farming, switching to less water intensive crops, or dry land retirement. Farmers practicing dry-land farming in arid regions use a variety of techniques and land management to minimize water loss and erosion. These techniques include coordinating seeding to the ideal soil moisture level, choosing crops suited to dry conditions, and set-aside. Decommissioning refers to a set of practices, in use for well over a century, like plowing a field in late fall or early spring to clear weeds and increase soil moisture. First plowing breaks up the land and allows the soil to absorb more water. It will also wick moisture away from weeds and create ridges in the land that limit surface runoff and more accurately capture moisture from snow. Set-aside can also include choosing not to plant a specific area for one or more growing seasons.
Land retirement refers to a common policy of permanently or temporarily suspending farming on a certain area of land in return for financial incentives. One of the most well-known land annuities is the US Department of Conservation Agriculture's Reserve Program (CRP). Through CRP, farmers are paid rent per hectare and an additional fee for providing land cover. While CRP is typically employed to control the agricultural market and to keep prices and volumes stable, the added value of conserving land and water resources has been more of a consideration in determining compensation for land retirement since the late 1990s.[7] This type of financial incentive is common among land retirement programs .
Benefits
Practices such as chiseling, furrow levees and land leveling allow the land to use water more efficiently and the results in less waste to be absorbed. It is also one of the cheapest methods of agricultural water conservation discussed in this report. Depending on the elevation of the land needing irrigation and the alternative chosen, it might be possible to remove an irrigation diversion dam, particularly when used in combination with one of the alternative diversion methods described above. Dryland farming and land retirement, also mentioned above, have the most to offer in terms of water saving simply because they require the use of little to no water, and the potential for dam removal.
Disadvantages
While chiseling, furrow levees and land leveling help drain and allow the land to retain more water, they still don't address the over-irrigation issues that results from gravity-fed irrigation systems. Also, dry-land farming and land-retirement practices seem related, suggesting that farmers are going the economy. Discussions centering on these alternatives should take current and compensation into account. Also, rarely, if ever, dry-land farming and land-retirement practices are employed by the large agribusinesses that now dominate the industry.
costs
As previously mentioned, furrowing and other land leveling practices are the least expensive irrigation alternatives discussed in this report. The actual project costs will vary depending on the height of the area, topography of the country and the region or country in which the farm is located. According to the 1998 Farm and Ranch Irrigation Survey, investments in the United States for agricultural improvements were $643 million for irrigation equipment and machinery, $138 million for the construction and deepening of wells, and $190 million for permanent storage and distributions, and $83 million for land clearing and course. [8] In order for chemical land farming and land retirement to be possible for farmers, it must often be accompanied by financial incentives such as conservation easements,
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