Soil type not available in app


#1

Hello,
I am a new Rachio user and still tweaking my settings to get everything running properly. Had a question about which soil type to choose in the app. Looking up my soil at the Web Soil Survey, I have silt loam type from the triangle chart. In the app, soil types look to change mainly the absorption rate of water applied. Are those the numbers associated with each soil type?

Here is the triangle diagram, and only those soil types available in the app, and their default absorption rates:

My soil type is shown in the red circle, would this behave more like sandy loam? Are we able to edit this absorption rate number in an advanced setting, if it was very different from the available defaults?
Finally, if more organic matter is amended to the soil I assume the absorption rate number would increase?

Thank you


#2

That’s the same type of soil I have. Actually mine is Hastings silty loam.

If you choose loam it will default to .17 for available water. Mine, after looking it up, is actually .19, so after choosing loam, I adjusted available water to .19.

Mike


#3

@redwagon You’re right that the soil choice defines the absorption rate. The absorption rate, in turn, determines whether or not you will cycle-soak if you have the ‘Smart Cycle’ enabled. However, the more key setting here is the Available Water Capacity (AWC) that is set by default, but that can be changed in the advanced settings. The AWC will help define the watering duration and frequency. The nice thing is that the Web Soil Survey gives you the actual AWC number. I’d pick the closest soil that you can for the absorption rate, then enter your actual AWC into the Available Water customization.

If you’re not sure how to get the AWC number from the Web Soil Survey here’s a link to guide you once you’re there.


#4

Thank you, that is good to know that soil type effects only smart cycling and, it appears, the default AWC value. My available water at web soil survey is 0.09. Does that sound right for a silty loam soil type?


#5

@redwagon. I don’t have experience with that soil type. However, based on @runner1717’s post above it sounds low. Maybe take a screen shot of what you’re seen at the WSS site that shows both the soil type and AWC number? You can also try to put it into your zone then look at your moisture graphs, under the schedule setting. Low numbers will predict watering frequencies that are shorter than you might expect. Higher numbers will decrease that frequency. The WSS site is usually pretty accurate, but be sure to be zoomed into you neighborhoods.


#6

It’s hard to,say. I would go with the soil survey and if you feel groggy, bump it up each week until you see heat stress.

Or compute it yourself.


#7

I discovered the issue with my AWC value at the WSS site. I originally got the number based on the all layers button. If I adjust that to just look at the top layers, then the value is a more reasonable 0.19.


#8

Just my gut, but it seems that if roots are only going down 4-6 inches, than using the bottom depth of 8 would probably give you a better reading. I’d agree with going with .19.


#9

@redwagon I agree with @linn, and your updated analysis of the data (down to 8") that the 0.19 number is more reasonable. Keep in mind that your watering frequency will decrease though. Take a look at what it gives you. In case it’s too big of a jump from what your lawn is used to you may have to start with a lower MAD and work your way up to 50% over time.