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Dripline technology is a science on its own as Zambian farmers could find out from the representatives of the Israeli born company, Rivulis, displaying their excellent products at the Agritech expo.
Eleven factories in nine countries worldwide manufacture driplines using technology from Rivulis, incorporating their specialised integrated drip tape, moulded drip lines, micro sprayers, and online drippers. T-Tape was the star attraction at the Rivulis stand. The T-Tape pipe is based on the same principal as the other Rivulis “moulded” drippers, with much more technology on the inside than meets the eye.
The design equalises the speed of the water and causes a turbulent flow. The T-Tape has a continuous flow path moulded or integrated as part of the pipe in the manufacturing process, where a sheet of flat polyethylene is imprinted with the integrated emitter, through heat welding. Because Rivulis T-Tape has emitters “manufactured” into the tape itself, as opposed to inserted moulded emitters, there is no cost difference per metre between 10 emitters per metre (10 cm spacing) and two emitters per metre (50 cm spacing). T-Tape helps make your choice of emitter interval spacing an agronomic decision, not one based on your bank account.
The inlet distributes the water to the flow path or labyrinth, which influences the flow of the water and ensures that the same amount of water is distributed to each dripper over the length of the pipeline.
“The pressure at the beginning has little to no influence because of friction and if you keep to the limits set for pressure and length of the pipes, you will receive 90% uniformity,” says Elias Kampher of Rivulis South Africa.
The emitter out of which the water flows into the soil requires very little pressure to operate, 0,55 bar to be specific. This means that it is very affordable, because farmers do not need to invest in pressure pumps. The slit outlet automatically seals when the system shuts off, which is very beneficial because it prevents particles like sand from being sucked into the drippers when they are used underground. Air valves are also placed on the pipeline to ensure that air bubbles can escape, because the longer air is trapped in the pipe the bigger the chances are that your pipes will block or even burst. T-Tape Drip Tape can be installed on the ground, under plastic, or even used for subsurface drip irrigation (SDI).
“It is the perfect SDI application for lucerne, cotton, sugarcane,maize and other permanent crops. You just have to choose the correct wall thickness to use it underground. It is a non-pressure compensated product and will perform well if the set-up is designed well,” says Arjan Janknegt from Rivulis Netherlands.
The main advantage of SDI is that water is applied directly to the plant root zone, saving a lot of water. The low application rate promotes uniform and deep watering. It reduces soil compaction and can be used for fertigation. Irrigation can be applied at any time and is not affected by wind. Rivulis has developed software programmes for designers to use when they customise the drip line systems. The design has to compensate for a pressure loss of 5%, but it can also be tailor-made by determining the exact pressure loss. The design will depend on the conditions in which it will be used.
“In Africa the use of driplines is slowly expanding. Labour availability and land use are going to be key to the next step in the development of drip irrigation systems,” Arjan states.
Some of the other Rivulis products catching the eye include the very popular Rondo Mist. This is a double purpose sprayer, it is static and does not swivel as it is mainly used for overhead, inverted application in greenhouses as irrigation for seedlings. Other products include non-regulated micro sprayers, also used for overhead and upright application, and the Rondo RFR, a flow regulated version of the Rondo micro sprayer that is based on the same principal as the drip sprayer, especially for uneven terrain.
The main reason for these products being so popular, are the anti-leak valves they come equipped with, that can be opened up and cleaned, whereas the competitions’ products are not equipped with that function.
For any other information regarding T-Tape or Rondo products from Rivulis, please contact the local distributor, Bram de Vries, at +260(0)978-513-396, or email@example.com. Also visit www.hollandgreentech.com or find them on Facebook: www.facebook.com/hollandgreentechzambia