Which soil type to use in the app?

Getting Started
1

I have the following:
Sand - 68%
Silt - 10%
Clay - 21%

According to the USDA Soil Texture Calculator I have Sandy Clay Loam. According to this web page:
What soil types are in the Rachio App?

Sandy Clay Loam isn’t an option. Therefore, what type do I choose?

2

@Fl-user welcome to the Community. From your percentages, it would probably be called Sandy Loam, but if you’re looking for something between Sandy Loam and Clay Loam (which the USDA Calculator is probably trying to tell you), tell Rachio it’s “Loam”, which is an option.

Rachio’s use of the soil type influences (in part) how much and how long your root zone can hold water applied to it. This soil type represents your best description of what’s in the zone’s growing profile - the root zone and drainage. You’re doing the right thing - making an educated guess. You can always tweak it later if necessary.

1 Like
3

An alternative is to use the “advanced” settings to set the “Available Water” value.

  1. Select your zone(s) and click on them one by one.
  2. For each zone, click on “Edit”. This opens the available settings for your zone. Instead of selecting a “Soil Type”, go the the bottom and …
  3. Select the “Advanced” choice. This opens the “Advanced” settings page.
  4. Enter the value for your specific soil here in inches per inch.
  5. Fill in other fields as you like if you want to depart from the defaults that the “Soil Type” on the previous page gave you. Finally…
  6. Click on [DONE].

Now, where do you get the “Water Availability” info? Probably the easiest way is to contact your local U.S. Department of Agriculture Service Center via “offices.sc.egov.usda.gov/locator/app”. There you can select your state and county to get contact information for your local office. Just give them a call and let them know what you need.

As an alternative, the British Columbia Ministry of Agriculture gives some standard values for “Available Water Storage Capacities” in inches per inch. (most resources give in centimeters per meter). Although, as with the Rachio choices, Sandy Clay Loam is not listed, Clay, Clay Loam, and Silt Loam are shown as 0.21 to 0.20 (in. water / in. soil). See “irrigationtoolbox.com/ReferenceDocuments/Extension/BCExtension/619000-1.pdf”. This should be close enough.

4

@GAJett

Thanks for that information. Currently the grass is barely growing due to the time of year. I told Rachio that it is sandy loam for now. Per the pdf you linked to, it correlates to 0.12. Maybe I should change it to Loam which is 0.18 per the pdf later in the spring. Using the 0.12 value I may be using slightly more water than needed but I’m using a lot less water than what I had been doing by using a Hunter controller and watering twice a week unless it rained 0.25 in or more.

The soil here was moved from elsewhere in the area as this area has been built up so it may not be representative of what the county would have on file. However, I will check with them and see what they say. I appreciate the info and links.

Is there any way for me to do the testing to determine a number myself using my soil?

5

@GAJett

The position for conservation is vacant according to the USDA Service Center Locator and listed the person 1 county over. I have emailed her asking about the AWSC in my area. I hope she can shed more light on the value.