The last decade has seen innovative irrigation technological development. Initially developed and tested in a commercial environment this technology is now being applied to residential gardens. A recent Australian publication ‘Water Use Efficiency for Irrigated Turf and Landscape’ (Connellan 2013) is an important resource for practitioners that will benefit all gardeners.
Sprinkler irrigation is often compared to rainfall. Sprinklers (or rotators) provide a rotating stream of water that constantly moves. Sprays continuously apply water to the same area. The great challenge is to provide uniform distribution of water over the watering area. Historically sprinklers and sprays have not provided a uniform distribution, requiring some areas to be significantly over watered to ensure the whole area receives a minimum amount of water.
Advantages of sprays and sprinklers
- Large areas can be irrigated
- Precipitation rates can be varied
- They are suited to a wide range of topography and soil types
- They are potentially highly efficient
Limitations of sprays and sprinklers
- Evaporation losses can be significant
- They require medium to high pressure and can use significant energy
- Prone to wind spray, reducing efficiency
- They wet the foliage so the risk of disease is higher
There has been a breakthrough in recent years with multi-stream multi trajectory rotators, often known as the Nelson MP (matched precipitation) rotator, providing highly accurate, wind resistant distribution. These sprinklers also provide reliable coverage regardless of the area being irrigated, this is called matched precipitation – any arc, any radius, the precipitation rate stays the same. Additionally precipitation rates can be reduced to 1/3 that of spray heads, increasing infiltration and decreasing run off. Manufacturers claim this technology will use 30% less water than traditional sprinklers and sprays and it has been widely adopted by the irrigation industry.
Have you bought an irrigation system recently? What kind of system did you go with?