Irrigation - Experimental. Nozzling, Repair

This post will cover all things used along with conventional irrigation systems to modify and enhance them to address specific problem areas. This post could get rather lengthy so it may be split into multiple posts later on.

Subsurface Drip Irrigation

Subsurface drip irrigation is an extension of standard above-surface irrigation used to address an area with a steep slope or an irrigation shadow space (in which the irrigation cannot land properly). At Lahontan Golf Club we implemented multiple sites of drip irrigation on bunker edges and faces. These areas needed attention for both of the previously listed reasons. They were also in sun-baked areas where expelled sand had taken over most of the profile causing higher than normal soil temps and accelerated drying times.

Below is a picture of a subsurface drip that has been cut and assembled in a cascading layout down the slope. Spacing was set at 12" (30cm) and looped together at the ends to create a free-flowing system with no dead ends. It was then buried 1-1.5 feet (30-45cm) below the surface and tied into the lateral line with an electronic valve. It was then given a station number via the computer and ran anywhere from 60-120 minutes a night. 

#12 Fwy Bunker Drip (South Facing)

A big secondary benefit to subsurface drip irrigation systems is that they may be run during the day when play standing on top of them. They are silent and let out a low amount of gallons per minute. They can be used to cool the rootzone during hot summer days and times of water starvation for tournaments. On days like this, they were run 120 mins a day in 20 min time slots in the heat of the day.

Nozzling

Nozzles in your irrigation heads can be changed to give you different patterns of water applied, amounts of water applied, and help you achieve better uniformity while irrigating. 

Above are some brass nozzles that were trialed in some of our irrigation heads at Lahontan Golf Club. They were a direct factory replacement to the Toro nozzles provided with the heads. The purpose of the test was to see if uniformity rates could be improved while also extending the life of the nozzle itself. Standard nozzles provided are made of plastic and have a life of around 5-7 years depending on how much silt and fine particles are making it through your filtration system. (More on pump filtration in Pump Systems) What we found is that the uniformity is similar, so that was a win. However, the increased cost of the brass nozzles was a concern. The brass was 10x more expensive than the plastic and without a sight testing them for years at a time we have no way of knowing how long they will last. I assume that In applications where there is no system filter the brass would outlast the plastic and cost less in the long run. One should also consider the mineral content of your water, as brass will accumulate lime (Calcium Carbonate where plastic does not. 

Irrigation Leveling Techniques

At many irrigated sites around the world, we see the problem of sinking irrigation features. Heads, Quick Couplers, and Valve boxes all settle over the years causing them to lose efficiency. To combat this one must dig up and re-level these sinking irrigation features. No matter how well packed the original construction was there will always be some amount of settling.   

Quick Coupler and Head showing signs of settling.

Step 1: Remove a generous amount of sod in four squares around the irrigation feature so that you may expose the lower workings. Tip: Make sure to cut straight lines on the edges and remove equal dept of soil across all of your cut squares. This will make it easy to repair the sod when you put it all back together.

A flat spade is the best for cutting and slicing your sod for removal.

Step 2: After all your sod has been neatly removed. (pictured below) You may then expose the swing joint and level up your feature. Tip: Use a long flat 2x4 or level to find how much the feature needs to be leveled. Too high and your mower will break it, too low and you have just wasted your time.

Square of sod removed and coupler leveled.

Step 3: Be sure that when you replace the soil you removed that you pack it properly. You should be able to fit more soil in than you removed. The better you pack the soil the less chance this feature has of being dug up again for re-leveling.

Sod replaced and features leveled.

Step 4: Replace the four pieces of sod that you removed earlier in the same positions they were originally in. Tamp lightly with a tamper and continue to hand water until sod takes hold.

Leveling up your irrigation features will provide multiple benefits and is always worth the labor time. A level irrigation head will provide better uniformity and that benefit will make that area require less hand watering. A level quick coupler/valve box will lead to fewer broken valve covers and be easier for your hand water to find causing him/her to spend less time in each area. Small amounts of time saved while hand watering can add up to a lot by the end of an 8-hour shift equaling more locations that the employee gets to throughout the heat of the day.

Small Sprinkler Application

During my time working with irrigation, I have come across some small area application sprinkler systems. These systems are used for spot watering without the use of a person standing there. They are the "Set it and forget it" mentality. At times sprinklers are left out overnight at a very low setting to soak a stubborn hot spot.

This is a setup that was suggested by a Toro rep. in Northern California. Its constructed entirely of PVC and has a small hunter/toro nozzle at the top. Multiple different options are available for different applications. This type of small application sprinkler can be used as a single unit or linked together with multiple units.

This application is something that was already in place when I came to Lahontan Golf Club. I took it with me to Victory Ranch Golf Club. It has a similar idea as the sprinkler above but is more durable and meant for larger areas. The idea here is to send one worker out with up to 50 small hoses and sprinklers to be placed in dry areas around the course. The worker then moves them around as needed until all areas have been properly irrigated.