Crop Coefficients and Plant Type

Post by spaceman_spiff on Feb 9, 2022

As someone who lives in northern California, this feature is going to be awesome! My lawn gets absolutely nuked during the summer months and I have a phone reminder to adjust my grass crop coefficients on the first of every month according to the chart posted above. When using the default 80% throughout the year, I also see the opposite issue of water being applied too frequently in the cooler months, which has resulted in a nice infestation of rust and Pythium blight fungal infections. Not cheap to treat!

If I opt into this dynamic crop coefficient, will there be any option for an offset to the dynamic number?

For instance, I have one of my cool-weather grass zones saturated in tree roots in the soil. These suck up so much water, so the ‘fix’ I use is I increase the root depth from 6" to 8" and offset the crop coefficient from that chart above to +0.2. That way it applies more water at once, but also keeps the watering frequency the same as my other zones. I would like to use this dynamic number, but also have it apply a constant offset to keep this zone happy.

Post by Thomas_Lerman on Feb 9, 2022

Maybe you already provided it and I missed it... where can we fix the coefficient curve for my area?

Post by ECOBEARD on Feb 9, 2022

Why do I see this every once in awhile on the app? I am assuming it’s testing for a future update.

Post by drew_thayer on Feb 25, 2022

HI @spaceman_spiff, your experience is exactly the kind of problem we had in mind in designing this feature. I think you’ll be pleased with the results.

We are getting ready to release this feature soon this Spring and have not included an offset in the first release feature set, but it’s a good idea and we’ll definitely consider it for updates. We’re always iterating and trying to improve our features.

Post by drew_thayer on Feb 25, 2022

@ECOBEARD This indeed is a beta test of a feature we are trying out. We are comparing your zone’s water use to a basic water-to-et simulation; the idea is to provide home irrigators with some useful feedback so they can have an idea of the effect of adjustments they make.

Post by ECOBEARD on Mar 23, 2022

Any updates on the dynamic crop coefficient function?

Post by drew_thayer on Mar 23, 2022

We are doing final quality assessment and hope to release it within the next two weeks!

Post by ECOBEARD on Mar 23, 2022

I am looking forward to it. I wonder how this will work if you know your area doesn’t fall into the default crop coefficient for a certain plant type. For example, I primarily have Turf Type Tall Fescue and Hybrid Bluegrass that appear to need less water than the average cool-season crop coefficient curve, especially because I only use slow-release fertilizers. Crop coefficients appear to be a spectrum and not a hard number.

Post by JCE on Mar 29, 2022

Definitely looking forward to this. The missing link. Have been using your controllers since they first came out. Now on Gen 3.

Post by spaceman_spiff on Apr 1, 2022

My iOS app now has this dynamic crop coefficient option in the advanced menu for my zones. Sweet!

Post by ECOBEARD on Apr 1, 2022

I noticed that annuals and perennials vegetation type have been merged into flower gardens. How do the setting vary compared to the old annuals and perennials?

Post by twin1 on Apr 5, 2022

Are these documents available yet?

Post by Tintn00 on Apr 6, 2022

Would love more description about this new dynamic crop coefficient.

Post by twin1 on Apr 7, 2022

It seems to me that when I select dynamic crop coefficient, I can not adjust the number at all. Are you seeing something different? Perhaps @drew_thayer can help us better understand this new feature.

Post by tmcgahey on Apr 7, 2022

I’m also curious how the adjustments are made. I really hope that it is using controller address to set a local, regional crop coefficient.

Post by Kubisuro on Apr 10, 2022

I have manually adjusted my ETc by the month and that, for stone fruit trees, results in a dramatic increase of ETc.

Post by ECOBEARD on Apr 13, 2022

I created some example crop coefficient curves based on AZMET values. My lawn example crop coefficient values are lower due to the footnotes from the AZMET snip.

Post by twin1 on Apr 14, 2022

It would great if we could input a crop coefficient for each month of the year for each zone. The dynamic crop coefficient may be too high/low for our particular location, plant type, etc.

Post by drew_thayer on Apr 19, 2022

Hello all, we’re excited to see the interest in the Dynamic Crop Coefficient feature. We’ve written up an FAQ document that will address many of your questions, here: Dynamic Crop Coefficient FAQ

Post by tlight on Apr 20, 2022

I am still not seeing this feature in the web interface at app.rach.io…

Post by championc on Apr 20, 2022

Hi there, you mention “a Mediterranean climate”. My unit is installed in South East Spain, so it actually on the Mediterranean coast. Can I make use of this feature ?

Post by drew_thayer on Apr 22, 2022

Hello @tlight, we are not yet supporting the feature on app.rach.io; it is currently only on mobile.

Post by Gardencat on Jun 29, 2022

I wonder how Rachio save water? It seems the only thing Rachio adjust is crop evapotranspiration.

Post by teresariedlinger31 on Aug 2, 2022

Thanks for sharing the tips. I have never considered this coefficient, and it’s my first experience with them. Right now, I am researching them and hope to implement them successfully in my garden work.

Post by tmcgahey on Aug 2, 2022

At the end of the day, vegetation needs the water that it does. Rachio isn’t going to make plants require less water, but what it does is adjust for various weather conditions.