Overwatering in Winter


#1

@bugs30 Continuing the discussion from Engineering team hard at work on v3!:

Do you mind telling me what kind of schedule you are running? Also, which Weather Intelligence features are you using on your schedules? We definitely don’t want to be over saturating your lawn and your neighbors! Sounds like something is definitely off.
Let me know!

McKynzee :rachio:


#2

The following settings were changed with the help of your staff. I have St. Augustine. With the recommendations of your staff I have performed a soil test multiple times, measured the watering rate of each zone multiple times, created my own nozzles to compensate since the ones available didn’t match the measured rate, and installed my own weather station since the closest official often has large differences in precipitation even being only a few miles away. Even with this setup my lawn kept getting too dry during the summer months last year and then as temperatures the watering rate barely changed. At one point I paused the system for a month just to let things dry out. As you can see, I just received an inch of rain a few days ago and I used my digital moisture meter today and the soil still shows heavily saturated at 3". It has been fairly mild here and yet the Iro wants to do a full watering tomorrow. My weather station is off currently about 3-5 degrees but that shouldn’t cause the system to water as much as it does now. It hasn’t been warm enough for that much evaporation and my grass is just now coming out of dormancy so it doesn’t use my moisture yet. It seems like the only time the system works correctly is during mid spring and mid fall. During the extremes it struggles.

Here



#3

I forgot to mention I am running a Flex Daily schedule.


#4

is your grass established? the first thing i noticed was shallow root depth of 4", which means the Rachio will want to water more often. If you’re grass has been around for awhile, you probably have a long roots, which will have the Rachio water a bit longer per session, but increase the time (days) between waterings. I’m not familiar with your grass that much but established bermuda gets plugged in to 9" or so


#5

The grass is 2 years old and has a root depth of about 6 inches last I checked. The shallow root depth was added because when it was at 6 inches it left the top of the grass to bake in the sun and burn. At allow depletion of 50% to a depth of 6 inches meant the grass would be curled up and burning between watering cycles in the summer. But that is my issue. During the milder seasons it works great. That said, even with a root depth of 4 inches it shouldn’t be watering when you can stick your finger into it easily to a depth of about 4 with light pressure it is so saturated. Shallow root depth wouldn’t cause that.


#6

This really sounds like the problem I have with super saturated soil (>110%) that the Iro currently does not deal well with. I have to fill the soil when the real content gets down to the 110% cap because the Iro doesn’t deal with water content above that level so it “just does not exist.” Fortunately this year is the first where we have got so much rain that the problem exists.

Anyway, on a different thread the response was that the cap would be revisited in the next update.


#7

@bugs30

I’d try a couple things to further tune your system. I had our support team review your zone settings and based on the settings I would switch your root zone back to what you think it truly is (6 inches versus 4). From what you’ve mentioned, I’d try changing to a silty clay soil which will bring your available water capacity down (from .2 inches to .16 inches) which should help in the summer months watering more frequently. Also, the easiest lever to use once you have those fixed is to adjust the crop coefficient slightly up (10%?) in the summer months if your lawn is looking stressed. This will increase watering frequency without adjusting watering duration.

My recommendation is try these settings on one or two zones and see if it is helpful. If it is you could move the rest over.

Once we’ve released our new software platform this year I really want to go back and make these adjustments much simpler so there really is only one lever to adjust.

Hope this helps.

:cheers:


#8

Will this help stop it from watering so much during the cold months as well?


#9

@bugs30, I would second @Modawg2k. 4" is a very shallow root zone depth, which decreases the size of your “Water Tank” – warm season grasses have an effective root zone depth of 6-12 inches – the “effective” root depth is considered the top 50% of root zone; or the roots you can see with your eyes.

This is a good example of turf that likely has a shallow root zone depth. I’d recommend setting the root zone depth to the target effective root zone depth for warm season grasses (Rachio defaults to 9" for warm season grass). Doing this now will help the grass grow proper roots for the upcoming summer months.

Out of curiosity, can you share the soil test results and your catch cap results? The screen shot of your zone indicate you’re using a default nozzle for Zone 3.


#10

@emil The shallow root depth is as measured the last time I changed it. The maximum roots as measured at the time were 6" deep. For summer of 2016 I reduced it from 6" to 4" as recommended by support as that were my shortest roots and I was having such problems with drying out during July and August I ended up with a chinch bug infestation due to heat and drought stress. Problem is the same settings are causing overwater during the off season.

The soil tests I performed four times in multiple locations. The results came up as mostly clay loam with small pockets of clay. I had two other people follow the same instructions with me and we all agreed on the results that the soil came up as clay loam.

I threw away my catch cap results after I was created my new sprinkler head. I did purchase an actual kit to measure and was going to try again. Previously I measured in 4 spots. This kit comes with 10 cups to measure to get a better average of the zone.

You are correct that I am showing a default nozzle on this zone. This zone was able to use a default nozzle and yet from my measurements and yet it is more saturated than the ones with the custom rotators.

This all still doesn’t address my other concern. If I fill a zone manually the algorithm is calculating my soil as drying out far faster than it is for the conditions during the moderate months. It seems to think the soil can lose roughly 40% off it’s moisture in 4 days when the temperatures are only in the 50s to 60s with humidity in the mid 40s and overcast skies with little wind and the grass isn’t even growing yet. I can put a moisture probe in the ground and find the soil in the first 3 inches has gone from wet+ to wet during that same time and I can easily penetrate the soil my fingers.