| The Advantages of Overhead Micro-Irrigation for Vegetables |
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| Cobi Shilo, Agronomist, NaanDanJain |
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The success of micro-irrigation has enabled the development of a new approach to overhead sprinkler irrigation. After a long period of stagnation in the overhead irrigation market, dramatic economic and agrotechnical progress has been made, and new products can now be offered. The use of plastic pipes, sprinklers and other accessories contribute to cost-savings and a longer product life.
The micro sprinkler stand system was developed for application in vegetable, strawberry and potato fields, and nursery and greenhouse crops. The versatile irrigation system is installed during the growing season and wound up for storage and the end of the season, in a way similar to the drip system. |
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The main features of the new irrigation concept are:
- Low precipitation rate
- Low operating pressure
- Short irrigation intervals
- High water and fertilizer distribution uniformity throughout the field.
Cost reduction and the very low precipitation rate are convincing more and more farmers to switch to permanent and semi-permanent irrigation systems. In addition to the clear labor-saving advantages and convenience, solid set irrigation has two more advantages:
- Flexibility in irrigation design and management
- Improved fertigation and water distribution uniformity.
The overhead micro-irrigation system achieves three main principles, which contribute to optimum production conditions, and consequently, maximum profits:
- High water distribution uniformity of up to 93% CU with a low precipitation rate
- (3-4 mm/h)
- Accurate fertilizer delivery through the sprinklers (fertigation) to any required location.
- Light pipes and sprinklers, which are easy to handle, quick to lay and retrieve, and cost effective.
Agrotechnical, Economic and Environmental Advantages:
- Eliminates runoff: Runoff and soil erosion is eliminated due to the low precipitation rate and fine droplets.
- Minimizes pollution: Accurate control of the soil wetting depth minimizes water leakage and mineral wash off, eliminating pollution of aquifers.
- Perfect germination: Fine droplets prevent crust formation on the soil surface. The optimal moisture for germination in the soil’s upper layer can be maintained by several daily irrigation cycles.
- Incremental sowing and planting: Accurate control of each lateral enables incremental sowing and planting in the same plot.
- Accelerated crop growth and development: Balanced air-water ratio results in healthy, fast growing plants.
- Wind resistance: Strong water jet irrigates complete blocks, instead of single rows, considerably reducing wind factor.
- Economic advantages: Flow rate is 60-70% lower than that of conventional sprinklers. The initial investment cost of the pump, pipes, valves and other equipment is lower. The new sprinkler system operates reliably with no leaks or pipe bursts. The equipment is durable.
- Ecological advantages: The system uses water efficiently, prevents pollution of underground water resources, saves energy and allows long term use of plastic components.
- Water saving: Field tests and calculation analyses show a potential 25 - 30% saving in water compared to conventional portable sprinkler systems.
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Modle |
6x6 m' |
7x7 m' |
8x8 m' |
9x9 m' |
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501-U |
93.1% |
89.8% |
85.3% |
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CU% |
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4.4 |
3.3 |
2.5 |
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MM/H |
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502-H |
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91.8% |
85.1% |
88.0% |
CU% |
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5.37 |
4.1 |
5.37 |
MM/H |
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5022-U |
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93.0% |
CU% |
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4.4 |
MM/H |
Conclusion
The objectives for incorporating micro-sprinklers in overhead irrigation have been met with great success. The new system is very practical and enables growers to easily adopt the new irrigation concept. First applied in irrigation of lettuce and cabbages use of the system has expanded to other crops such as potatoes, peanuts, carrots, and flowers.
Over 10,000 ha. in Israel are irrigated by the micro-sprinkler system. Small as well as large growers benefit from the concept, which is an optimal solution for a variety of markets. | |
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