Is it possible to use micro-sprinklers to irrigate the lawn?

Question

While trying to solve the same problem I’ve inquired before — using shrub sprinkler heads in drip-irrigation system to water narrow side lawn — I am coming to realisation that even if pressure is enough to use them, 13 mm mainline drip tubing could simply not be able to provide enough flow to supply three or four of those at once. So I am looking at alternatives.

One such alternative I am considering is to use drip-system micro-sprinkler heads. They seem to be able to provide enough coverage (some of them can do up to 6 m (20 ft) radius), and with flow rates of 50 to a 120 litres per hour (14‒32 U.S. gph) should be able to deliver water at a rate of quarter to a half that of a shrub sprayer.

In theory it seems like a viable solution, if I simply set them to run, say, three-four times longer than conventional sprinklers to provide enough water. But I had been reading books, brochures and articles on micro-irrigation for a few days now, and hadn’t seen any specific recommendations for that application. I’ve seen some questions like that been asked on gardening forums, but either links were broken, or no useful information were present.

So, is it possible to use above-ground micro-sprinklers to irrigate small sections of turf lawn? Is there limitations on soil penetration by this method of water delivery? Are those sprinklers sturdy enough to withstand relatively heavy use over at least few seasons? Would more drought/resistant grass species be required? How does grass hight affect this type of irrigation?

Answer 1

They make special sprinkler nozzles for dealing with narrow strips. They're called end strip and side strip. They have a more or less rectangular spray pattern. All major manufacturer's I've seen have them and they're designed to provide the same precipitation rate as other sprinkler nozzles in the same line so you can keep them on the same zone provided they design and spacing is correct. Irrigation Tutorials indicates the side strips have a better pattern than the end strips.

Update:

Ok, now I understand. There's reasons that irrigation designers separate shrub and lawn areas. They have different irrigation needs.

Most drip line and drip emitters (which you said you'd like to combine) need to run at a lower pressure than sprays. The micro sprays you're talking about will function at lower PSI but the radius is going to be less.

To get even head to head coverage in your 19'x10' area you're going to need 6 spray heads. One 90deg on each corner and 1 180deg in the middle of each 19' side. That's provided you can get 10' radius out of them at the pressure you're running the system at. You said specs indicated you can only get 4 on a line to run at a time. If you don't have 6 you're going to have a dry spot in the center of the lawn area.

Go through the irrigation tutorial link I sent if you're serious about trying this. It shows you how to do all the calculations. There are a lot of factors that go into this. You have the specs for the devices you'd like to use. Do the math and see if it works out.

If you planned out the drip area you should know what pressure it's going to run at. You'll need a pressure reducing fitting in most cases. From what I remember most of his examples use 3/4" or 1" main lines but if you can find the appropriate specs for the 1/2" line you can use the same formulas.

Regarding grass height, as long as the streams of water are high enough so that they don't get blocked by the grass you should be fine. I'd be more worried about mowing around the sprinklers without damaging them.

Answer 2

I've established native grass meadows in full sun in hot dry New Mexico with drip micro sprayers. They're cheaper, easier to install, easier to maintenance and don't seem to require an astronomical flow rate. The only concern would be if you have a rogue yard maintenance man who mows over them, or kids playing soccer etc.