Settings for deep watering
I am using RM on a 100% drip system for newly planted shrubs and trees on 3 zones in the Phoenix metro area which has little rain and terrible hard clay soil . Settings are:
- Vegetation: Bushes
- Soil Type: Clay
- Slope: Flat
- Sprinkler Head Type: Surface Drip
- Sun Exposure: Partial Shade
- Area: (# square feet by zone)
- Total Flow: (total gallons per minute for all drip emitters in zone)
I have enabled weather and seasonal adjustments and adaptive frequency. It is linked to NOAA.
We were advised to opt for deep watering over frequent watering so I set the cycle to every 3 days and it calculated the watering time accordingly. I found that it was going 6 days between watering when skipping so I set the cycle to every 1 day. It is now applying less water and skipping every other day.
I would like to see it go a minimum of 3 days between watering but water on the 4th or 5th day when needed rather than waiting for the 6th day. Is there a way to do this?
I am also concerned that the long watering duration from a multi-day cycle could over saturate the clay ground. Will the Auto setting for Cycles and Soak automatically split each zone's watering cycle into multiple on/off periods to avoid saturation?
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I would put it with a frequency of daily (you can use every 3 days though) and set a minimum watering duration threshold for each zone involved to a duration that you need to deep irrigate. This way it will only start when at least that duration is meet. It still won't be perfect but it might be healthy for what you need.
As for Auto-Cycle, yes it should work as you mention, it does depend on particularities of soil but in most cases it just does the job right.
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I changed the settings on Feb 20 to water Zone 1 daily with a Minimum Rollover Threshold of 2400 seconds (40 minutes). The weather here is pretty constant so there is not a lot of variation in watering time. It has been watering 20+- minutes every 2 days on the daily schedule so the 40 minutes is a test before I bump the minimum higher. Unfortunately, RM has now ceased watering completely, apparently because it is not accumulating water until the threshold is met.
- Feb 12 = 21 minutes
- Feb 13 = AF skip
- Feb 14 = 20 minutes
- Feb 15 = AF skip
- Feb 16 = 20 minutes
- Feb 17 = AF skip
- Feb 18 = 21 minutes
- Feb 19 = AF skip
- Feb 20 = 24 minutes
- Feb 21 = AF skip
- Feb 22 = 0 Min watering time
- Feb 23 = 0 Min watering time
- Feb 24 = 0 Min watering time
- Feb 25 = 0 Min watering time
I am attaching a screen shot of the settings page for Zone 1. I need help with this because it is not working.
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Prior to Feb 20, the system was on simple daily watering and it was watering every other day (Adaptive Frequency skip). To my knowledge, the Roll Over has never worked. It has never watered automatically since the Roll Over was established on Feb 20. Since then, the only watering has been forced manual watering and a deep fertilizer watering I did by hand. I have prepared a PDF with the history back to Feb but the reply will not allow me to include a PDF. I have emailed a copy of the PDF to your attention.
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Minimum watering time is working because:
1. It does not water since the duration is smaller than your setting
2. The water deficit increases
Water surplus is triggered when there is a surplus in soil, in your case there is deficit from the skipped irrigation due to minimum requirements (as that graph shows water surplus goes below green area).
Most likely in your case the system computed duration for irrigation is much lower than you would expect, resulting in several days of not watering (looks like around 10% of the set duration in zone).
We can give some advice to fix/improve once we take a look at your settings, for this you will receive a support request to access your machine, please approve that so we can take a look directly on your RainMachine.
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Hi,
I looked at your RainMachine settings, only Zone 1 has a minimum rollover time of 20minutes but this won't affect the algorithm since you already have Adaptive Frequency in your program which will try to water at least 60% of your time for deep root penetration. With your duration of 1h and 13min 60% will be always above 20minute of the minimum rollover.
I think your setup is very good, the only thing that I see that impacts the watering duration is that the Evapo-Transpiration for your location is pretty low + some rain reported. Along with 3 days frequency + adaptive this can result in more than 3 days skipped. With the Evapo-Transpiration that I see it can go 9 days+ without watering and then do a 100% or more to compensate.
Would this behavior affect plant growth ? No, if weather is correct and you don't have a micro-climate (ie: are the reported rain and temperatures correct ?).
So options to improve:
1. Weather correct: reduce field capacity to force algorithm to reduce the maximum days without irrigation
2. Weather incorrect:
2.1 Add another weather service like Wunderground, OpenWeatherMap to have better weather aggregation.
2.2 Check the wind sensitivity maybe you get more winds in your location than a normal urban area and increase using the slider from Settings > Weather. Usually wind greatly affects evapo-transpiration. -
Thank you.
I must be missing some critical concepts here. As noted above, when set to daily and AF enabled, it watered for 20 min every other day or 10/day average but when set to minimum watering time of 60 min, it never watered during a 9 day period with just .03" of rain. Since the surplus/deficit shows inches w/o time, I don't see a way to figure how much watering time would be required to relieve the deficit. I'd like to educate myself a bit to better understand what is going on without getting too technical. Can you recommend a video or specific KB articles?
The 20 minute minimum threshold on Zone 1 is experimental to get the hang of how minimum threshold works. My gut says that increasing MT a few times during the summer as it gets hotter could be the key to maintaining deep watering so I thought I would experiment with it.
My overriding concern is to get this setup correctly for summer when the AZ temps are extreme and deep but less frequent watering is critical.
We have no micro climate here or special concerns with the weather info.
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Adding some info. My initial setup was to water every 3 days with the assumption that if it did not water on day 3, it would water on the next day on which watering was needed (e.g. day 4, 5, 6, 7,...). This was my ideal and simple scenario for drip. Unfortunately, I learned that if it skipped on day 3, it then skipped to day 6 before the next watering which was allowing the shrubs to get too dry. (I have a moisture meter which I use to check the plant conditions in order to check the watering.) The introduction of Minimum Watering was the recommended (see Jan 11) solution; however it appears that the introduction of MW is merely complicating what should be a very simple setup.
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Deficit is shown each day in the water surplus graph. With AF enabled RainMachine wants to irrigate to at least a minimum of ~60% of the time you set which is considered 100%.
The 100% duration that you set (or it's recommended by algorithm) is proportional with base EvapoTranspiration (ET0) calculated for your location over a period of 20 years in the past.
With AF will accumulate deficit until 60% duration is achieved, unless it hits the Field Capacity "bottom". The minimum rollover works without AF, and can be used to overwrite the default AF algorithm (you can disable AF and just use minimum rollover). Also minimum rollover can force AF go higher than the minimum of ~60%, as you can control duration to let's say 80%.
The frequency is always respected and should be viewed as the minimal interval between irrigation. As long as you put minimum rollover and/or AF you can put daily frequency and still benefit of deep root penetration.
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