Overhead irrigation provides a clear view of how well the irrigation system is performing. The user can see how much water is being applied to the landscape, and maintenance is easier. Any clogging or issues with spray nozzle performance can be seen and addressed quickly, but overhead irrigation typically produces runoff and misting that create a lack of uniformity.
Most irrigation manufacturers offer overhead watering options for these narrow areas, such as side strip spray nozzles and short radius spray nozzles that can water distances as short as 0.6 m. However, these nozzles emit water at a much faster rate than soils can absorb, and the water distribution can be very uneven, resulting in overwatering of some areas and under watering of other areas.
With many traditional spray nozzles, the shorter the nozzle distance, the higher the precipitation rate and the higher the likelihood of runoff. If fertiliser is being used in a landscape where the irrigation system emits water faster than the soil intake rate, that fertiliser will runoff into the storm drains along with the excess water, causing the landscape to suffer and potentially contaminating the environment
A good option to reduce runoff when using traditional short radius spray nozzles is to use the cycle and soak program on your controller to break up the run time and allow the soil to absorb the water, but there is an even better alternative — rotary nozzles.
Rotary nozzles are the best way to efficiently water using overhead irrigation. Instead of a fixed spray pattern, these nozzles use rotating streams of water that cut through wind, reduce misting, and allow for a more uniform distribution of water at a slow, even rate that soils can absorb, significantly reducing runoff.
The latest innovation is rotary nozzles specially designed for narrow spaces. For example, the Hunter® MP800SR can reach distances as low as 1.8 m with a low precipitation rate that matches soil intake rates better than traditional spray nozzles. The side strip rotary nozzles can even reach distances as low as 1.2 m, and the corner rotary nozzles are great for irregular-shaped spaces. Combining these rotary nozzles with pressure-regulating spray bodies increases the efficiency of the system by ensuring that each nozzle receives the exact same pressure preset to an optimal amount for the nozzle. These short radius and side strip rotary nozzles provide an overhead irrigation solution to reducing runoff along sidewalks and eliminating wet and dry spots in narrow side yards between homes.
Subsurface irrigation is a great tool for new landscapes with tricky narrow areas. However, for existing landscapes, the rotary nozzle is the best solution to efficient overhead watering. It is simple to retrofit onto existing spray systems, and allows for easier maintenance and visibility in the amount of water being applied while maintaining a healthy green space.
For more information visit: www.hunterindustries.com