Sprinklers 101 - By Dave
We all spend so much money and more importantly time, on our sprinkler systems for our lawns and planting beds, so wouldn't it be nice to get the most out of every drop? I'm going to talk about some things that you can do to get things watered more efficiently. First off, let's see how we're balanced. I have some little measuring cups with spikes on them to push into spots where water is sprinkled to measure different areas of different zones and see how much water gets in the cups after the controller and runs through its zones. This is a great way to check if the dry spots are caused by lack of water or something else. In a perfect world all the cups would have the same amount in them after a watering cycle.
Some brands of rotor style heads come with nozzles already installed in them. The nozzles determine the amount of gallons per minute that flow through that head, and also determine the arc (distance thrown).
For instance, if a rotor in a corner (90 degree) has a 3.0 gpm nozzle in it, then there were a few half circle (180 degree) rotors with 3.0 gpm nozzles in them and lastly, we had 1 full circle nozzle with a 3.0 nozzle in it, what do you think the turf would generally look like in this zone? The corners would have a lot of water sprayed there (twice as much needed).The half circles would be just right and the full circles would be drying out. Why? In the time it takes for the full circle head to water one cycle (rotation) the half has gone two rotations and the quarter has gone four! So to get "matched precipitation " we would have to change the quarter circles to 1.5 gpm and the full circles to 6.0 gpm. Now all the turf is getting the same rate and things green up.
Now for the controller. I've seen some very clay soil types around these mountain valleys . Clay has a limited time of watering before it saturates and runs off or puddles. In my lawn, after about 22 minutes of spray it's saturated and trickles down the hill. So I use the electronic controller and split my run times into two, or sometimes three sessions. This allows the water to put on a partial amount that I need then let it soak for a bit, then the controller does the same thing two more times. By cycle soaking I keep my water on the turf instead of running it down the hill. This also allows you to water less days and helping the roots to get deeper. The last one I will talk about this time are types of heads. The two types are stream rotors and fixed spray heads. The rotors spray farther to cover more distance but only have one stream to apply water, so they need to have more time to irrigate. Fixed sprayhead nozzles cover shorter distance but water the whole pattern at once which cuts way back on the time needed to irrigate. When these two are mixed on the same zone, problems occur. To get enough time for the rotors to irrigate properly, the sprays would flood their area. To get just the right amount for sprays, the rotors wouldn't have enough time to put down enough water to help.
There are lots of new products out there to make things easier, contact me to ask how.
Next time we will talk about microspray and drip irrigation.