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. Drip irrigation is a very efficient way to irrigation crops and has the advantage of lower evaporation than other irrigation methods, it is the most common type of "microirrigation.
In drip irrigation, water is run through pipes with holes in them either buried or lying slightly above the ground next to the crops. Unlike spray irrigation, very little is lost to evaporation and the water can be directed only to the plants that need it, cutting back on water waste.
Microirrigation has gained attention during recent years because of its potential to increase yields and decrease water, fertilizer, and labor requirements if managed properly. Microirrigation systems can apply water and fertilizer directly to individual plants or trees, reducing the wetted area by wetting only a fraction of the soil surface; thus, water is applied directly to the root zone. Irrigation is one of the major uses of water throughout the world.
About 63, thousand acres were irrigated in 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.
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.
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, including. 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. The estimates put total withdrawals at the lowest level since before , following the same overall trend of decreasing total withdrawals observed from to Freshwater withdrawals were The estimates put total withdrawals at the lowest level since before Vast acreages of corn and soybeans are watered by center pivot irrigation in the Corn Belt states of the Midwest.
Activities associated with agricultural land use can have a profound effect on stream water quality. In spite of some very wet weather, this center pivot in southern Wisconsin is running.
Irrigation has been growing in the Midwest in recent years and it could be effecting the transport of agricultural chemicals to streams. Skip to main content. Search Search. Water Science School. Irrigation: Drip or Microirrigation. Drip or Microirrigation. Get water-use data. Water Use Information by Topic Learn more. Science Center Objects Overview Related Science Publications Multimedia 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.
Have your water analyzed by a laboratory that is qualified to evaluate emitter plugging hazards. Water quality might create limitations and increase system costs.
Filters must be able to handle worst-case scenarios. Finally, be sure to include both injectors for chemigation and flow meters to confirm system performance. Every trickle counts when you are battling a water shortage.
An ineffective or improperly managed filter station can waste a lot of water and threaten a drip system's fitness and accuracy.
In the western U. Screen filters and disk filters are common as alternatives or for use in combination with sand media filters. Sand media filters provide filtration to mesh, which is necessary to clean surface water and water from open canals for drip irrigation.
These water sources pick up a lot of fine grit and organic material, which must be removed before the water passes through the drip tape emitters. Sand media filters are designed to be self-cleaning through a "backflush" mechanism. This mechanism detects the drop in pressure due to the accumulation of filtered particles. It then flushes water back through the sand to dispose of clay, silt, and organic particles.
Sand used for filters should be between size 16 and 20 to prevent excess back flushing. To assure enough clean water for back flushing, several smaller sand media filters are more appropriate than a single large sand media filter Gleski, In addition to a sand media filter, a screen filter can be used as a prefilter to remove larger organic debris before it reaches the sand media filter, or as a secondary filter before the irrigation water enters the drip tube Figure 1.
For best results, filters should remove particles four times smaller than the emitter opening, as particles may clump together and clog emitters. Screen filters can act as a safe guard if the main filters fail, or may act as the main filter if a sufficiently clear underground water source is used. Figure 1. Drip irrigation systems with a prefilter, pump station with backflow prevention, and chemical injection site.
The chemical injection site can be before or after the main filter station. A pressure control valve is recommended to adjust the water pressure as desired before it enters the drip lines. A water meter can be placed after the pressure control or between a solenoid valve and each zone. An air vent provides vacuum relief.
Vacuum relief is necessary between the solenoid valve and the drip tapes to avoid suction of soil into the emitters when the system is shut off. If a drip hose system is used on the soil surface for perennial crops over a number of years, the drip hose should be lifted periodically so that leaves, soil, and debris do not cover the hose.
If the drip hose is not lifted, roots can grow over the hose, anchor it to the ground, and eventually pinch off the flow of water. Place a water flow meter between the solenoid valve and each zone and record it's gauge daily. This provides a clear indication of how much water is applied to each zone. Records of water flow can be used to detect deviations from the standard flow of the system, which may be caused by leaks or by clogged lines.
The actual amount of water applied recorded on the meter can be compared with the estimated crop water use crop evapotranspiration to help assure efficient water management. Leaks can occur unexpectedly as a result of damage by insects, animals, or farming tools. Systematically monitor the lines for physical damage. It is important to fix holes as soon as possible to prevent uneven irrigation. If the rate of water flow progressively declines during the season, the tubes or tape may be slowly plugging, resulting in severe damage to the crop.
In addition to maintaining the filtering stations, regular flushing of the drip tube and application of chlorine through the drip tube will help minimize clogs. Once a month, flush the drip lines by opening the far ends of a portion of the tubes at a time and allowing the higher velocity water to rush out the sediment. Because algae growth and biological activity in the tube or tape are especially high during warmer months, chlorine usually is applied at 2-week intervals during these months.
If drip lines become plugged in spite of maintenance, many cleaning products are available through irrigation systems suppliers. Choose a product appropriate for the specific source of contamination.
Manage irrigation and fertilization together to optimize efficiency. Chemigation through drip systems efficiently delivers chemicals in the root zone of the receiving plants. Because pf the precision of application, chemigation can be safer and use less material.
Several commercial fertilizers and pesticides are labeled for delivery by drip irrigation. Injection pumps with backflow prevention devices are necessary to deliver the product through the drip lines. These pumps allow for suitable delivery rate control, while backflow prevention protects both equipment and the water supply from contamination. Other safety equipment may be required; contact a drip-irrigation system supplier for details.
Soil microorganisms convert nitrogen N fertilizers to nitrate. Nitrate is water soluble, available to plants, and subject to leaching loss. Since nitrate loss management was one of the initial reasons for our exploring drip irrigation, it is appropriate that we revisit this topic.
Typically, when irrigation is monitored closely, less nitrogen fertilizer is needed with drip irrigation systems than with furrow irrigation systems because the fertilizer is spoon-fed to the root system and little is lost due to leaching.
For example, if a field is converted from furrow irrigation to drip irrigation and the amount of nitrogen fertilizer is not reduced, the crop may become excessively leafy which can inhibit curing and increase harvest costs as well as losses. Leaf tissue analysis performed by a qualified agricultural lab can help determine crop nutrition needs during the season, and tailor the N fertilizer applications to actual crop needs.
Fertilizer can be injected through the drip system. Fertilizer usually is introduced into the irrigation system in front of the filter station so the filters can remove any precipitates that occur in the solution. Fertilizers containing sulfate, phosphate, calcium, or anhydrous or aqua ammonium can lead to solid chemical precipitation inside the drip lines, which can block emitters.
Obtain chemical analysis of your irrigation water and seek competent technical advice before injecting chemical fertilizers into drip systems. Plan for seed emergence. The drip tape must be close enough to the surface to germinate the seed if necessary, or a portable sprinkler system should be available.
For example, a tape tube 4 to 5 inches deep has successfully germinated onion seeds in silt loam soil. Tape at 12 inches failed to uniformly germinate onions. The total irrigation water requirements for crops grown with a drip system is greatly reduced compared to a surface flood system because water can be applied much more efficiently with drip irrigation.
Applying more water than plants need will negate most of drip irrigation's benefits. The soil will be excessively wet, promoting disease, weed growth, and nitrate leaching. To determine application rates, use measurements of soil water and estimates of crop water use crop evapotranspiration, or "ETc".
For shallow rooted crops, irrigate only to replace the soil moisture deficit in the top 12 inches of soil. It usually is not necessary to exceed ETc. Daily crop evapotranspiration estimates are available locally on our Website. For information on measuring soil water levels directly, see Irrigation Monitoring using Soil Water Tension.
Add chlorine or other chemicals to the drip line periodically to kill bacteria and algae. Acid might also be needed to dissolve calcium carbonates. Filters must be managed and changed as needed.
Even with filtration, however, drip tape must be flushed regularly. The frequency of flushing depends on the amount and kinds of sedimentation in the tape.
Root intrusion needs to be controlled for some crops. Rodents must be controlled, especially where drip tape is buried. Drip Irrigation for Row Crops. Trickle Irrigation Manual. Van der Gulik, B. Micro irrigation Management and Maintenance. Hassan, Farouk A.. The book is available from Farouk A.
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