Dynamic Crop Coefficient

post by mc543 on Apr 9, 2022

Anyone appreciating the dynamic crop coefficient feature? I’ve always been manually changing it myself when the seasons changed.

In Houston Texas and it jacked up my St. Aug crop coefficient to 86%. Sounds pretty high! We’ll see how this goes. Tried to offset it by increasing allowed depletion up to 70%.

I see this post from @drew_thayer ( Crop Coefficients and Plant Type - #10 by drew_thayer) where he posts a link to Chapter 6 - ETc - Single crop coefficient (Kc) but the only table that lists a warm season coefficient is for subhumid climates. Would a subtropical humid climate change these coefficients or has the rachio software already accounted for this? Been having some large patch issues in the past and don’t want to overwater my lawn.

Is there more info about this new feature or are we in the guinea pig stage?

post by KidCapri on Apr 9, 2022

Personally, the documentation on how to use it and what it does, is pretty poor.

Seeing no benefit of using this at all here in the midwest (Wisconsin). Wish they would add more meaningful updates (like fixing the watering time before sunrise, and not having it water at midnight).

So no, not really appreciating it.

post by Kubisuro on Apr 10, 2022

More info like a table of values would be nice. Though at the moment it has my stone fruit trees at 46% which is about right for April. Come May it better shoot up to 85% or so. I’m keeping my citrus off dynamic since their ETc really stays essentially the same most of the year. I wish they had a way to specify evergreen or deciduous trees at least.

Keep an eye on it!

post by rraisley on Apr 11, 2022

Obviously, the dynamic crop coefficient is of extreme interest to me. And while I am also interested in the workings of it (engineer, after all), I’d like to know where it is.

I have an Android phone, and don’t see it there, nor on the Web version. Is this only available for iOS?

post by tmcgahey on Apr 11, 2022

It is in all platforms. Under crop coefficients you can choose to manually set, or lock it in and let Rachio adjust. The question in the other thread is how exactly it is going to work, and if it is regional or what.

post by rraisley on Apr 11, 2022

Thanks, it is there on the Android, but not on the web version, which does report the changed dynamic setting, but also allows you to change it. I usually use the web interface, being larger with more information and as I’m always at the computer.

post by rraisley on Apr 11, 2022

Oh, wow, while the one zone 1 I set explicitly to Dynamic did update on the web (from the default of 65% to 80%), the other zones on the web remained at the 65%, even though from the phone I specified to apply dynamic to All zones. That’s going to be a bit of a hassle until they update the web version. For that matter, which is used to actually operate the system when they differ like this?

post by MichaelS76 on Apr 11, 2022

I’m just now seeing this feature on my iPhone. Was this included in an update? Mine was setting locked at 80%. I just set to dynamic and it lowered it to 64% which raised my soil moisture by 11%. I guess I will leave it as dynamic.

post by tlight on Apr 19, 2022

I updated my iPhone app and then saw the option to switch to Dynamic. I switched all zones at that time. But this option is not showing in the browser interface (Chrome). Still shows the old static settings…

post by franz on Apr 20, 2022

It is live!

post by Gerardv514 on Apr 26, 2022

Why does this chart show 1.04 in April for cool season grasses, when peak summer is only .94?

ohh this is just for California

This is in the dynamic crop FAQ

post by ECOBEARD on Apr 27, 2022

That is when the grass is growing the fastest, growing the most, and going to seed, thus needing more water. All of this requires more water relative to other times when the grass is growing slower.

post by kuryanthomas on Apr 27, 2022

Is the dynamic crop coefficient intended for very high quality turf or just average home lawns? I’m interested in whether I can dial it back a bit if I’m okay with an average-looking lawn? (I understand that any dialing back would be manual, I’m not discussing an automatic offset here.)

Thanks.

post by mc543 on May 2, 2022

My crop coefficient just increased to 98% this month. Seems like a lot! Trying to offset by bumping up allowed depletion to 85%. Might just go back to non dynamic.

post by championc on May 6, 2022

A bug with applying the correct figure for Dynamic Crop Coefficient has been identified and fixed. If you have set it, it may be worth re-setting it back to manual again and then back to Dynamic

post by rraisley on May 7, 2022

My Warm Season grass Kc value for May is 74%, not 79% like the above chart shows. Last month it was 80%, not 72%.

post by championc on May 7, 2022

I had the problem and I worked with Drew and the engineers found the bug in their code and resolved it

post by Gerardv514 on May 7, 2022

The chart is based on California. Could it be location specific?

post by championc on May 7, 2022

Mine is in Spain. It was giving the Default value in April of 65% whereas my area should have given 54%.

post by rraisley on May 8, 2022

How can we find out what the Kc values are for each month? I’m afraid the only way I can use it is to change it manually, because IMHO the More/Less water feature is worthless, as you have no indication of where you stand and what is done. So the only other way to determine how much water I get is with the Kc, which I can change manually.

post by ECOBEARD on May 9, 2022

My preferred crop coefficient is 10-20% less than the dynamic Rachio crop coefficient based on my observation.

post by rraisley on May 9, 2022

Which would make a +/- % modification Slider for each zone perfect for working with dynamic crop coefficient. This really needs to be done; the current more/less is pretty much worthless, as you don’t even know what has been set.

post by Gerardv514 on May 11, 2022

I’m using a flex daily schedule with dynamic crop, why are my zones showing a regional watering target as using more water than average demand for this region, plant type, and season? I’m not really sure what more I’d have to tweak, I thought I have everything dialed in pretty well.