Micro-spray is a cross between surface spray irrigation and drip irrigation. It has some of the advantages and some of the disadvantages of each type of irrigation. Like drip irrigation, micro-spray is considered a type of low-pressure irrigation typically operating with pressures between 15 and 30 psi. It is generally considered low volume with application rates of 5 to 70 gallons per hour (gph) (18.9 Lph to 264 Lph). Micro-spray typically creates a larger wetted area then drip irrigation making it well suited for irrigating ground covers, large flowerbeds and sandy soil.
Micro-spray is delivered through micro tubing to a series of nozzles attached to risers. These risers may be fixed or designed to pop-up. In either case, it is easy to see that they are functioning, eliminating the most commonly voiced complaint about drip irrigation. It provides many of the same benefits as micro-spray irrigation with a few exceptions:
- It is less likely to be exempt from watering restrictions because it puts out a higher volume of water than drip irrigation
- It is subject to evaporative losses and spray pattern disruption in windy conditions
- Higher flow rates make it more susceptible to overwatering and runoff
- Larger wetted areas may result in more weeds
Micro-spray maintenance is similar to that of drip irrigation although it uses nozzles instead of emitters to deliver water. Nozzles are subject to clogging and disruption of flow pattern. Nozzles can be blown off due to high pressure; tampering with flow adjustments can result in flows that are too high or too low for the landscaped area being irrigated.