Hello okra lovers, my name is Jordan Collins. I am a botanist, also a recent graduate from Arizona State University. If you are a follower of Chris Smith’s work, then you may have heard me on The Okra Pod Cast discussing ethnobotany and the origin story shrouding Abelmoschus esculentus (okra). Or perhaps being the latest winner of the Tony Kleese Award. I am ecstatic to be working on one of the largest okra trials in U.S. history, perhaps the world. I am also here to share some of the skills I have developed and am employing for this current trial, and will share my process here so you can follow the trial and our methods.

The first thing any student engaged in the scientific study of plants wants to know before handling any plant material is the ground they are working with. For that, there are a couple of tools  (UC Davis Soilweb and Web Soil Survey) that are used to gather a preliminary understanding of the environment. In this first journal entry, we’ll be exploring the UC Davis Soilweb.

What is the soilweb? 

The UC Davis Soilweb is a map created in conjunction with UC Davis and the Natural Resources Conservation Service – USDA detailing all the different soil profiles across the United States and is updated yearly. So, let us take a step by step look at this tool, feel free to follow along in a separate tab!

When the webpage first loads, a welcome message is plastered over a map. Click OK and you are essentially seeing a Google Map rendition that has a soil survey plugin attached and functions the same as navigating Google Maps. In the top left corner there is a locator icon. Clicking the locator icon will use your Internet protocol (IP) address to relocate you to your current city. You still have to manually zoom to find your precise location.

In the top right there is a hyperlinked “link to WSS”, this is the second invaluable tool, but we will come back to that in another article. Under that is another icon that looks like a stack, called layers. This button changes the way the geography is represented. By default, it is set to “ERSI with labels”. ERIS stands for Environmental Systems Research Institute and they are an international distributor of GIS (Geography Information Systems) software. Clicking the stack icon will reveal several radio buttons with different ways of representing the map. If you are following along, we will leave it on default.

Under that icon is the “outline color” icon. This simply transitions the survey lines from yellow color to an off black hue.

Unfortunately, Soilweb does not feature an address search function to shortcut finding locations more easily. At the bottom are two buttons, zoom in, “+”, and zoom out, “-”). Lastly, under the “+” and “-” are the longitude and latitude. We can use these to locate Franny’s Farm and our experimental trial site (Lat: 35.6573 and Lon: -82.7444). To find Franny’s Farm (or another location) it is helpful to open another tab to Google Maps, copy and paste the address into it to gather the general area and the use Soilweb as a mimic.

The Trial Site at Franny’s Farm

UC Davis Soilweb Tool

Now that you had the chance to locate Franny’s Farm (or your own location) and zoomed in, you will notice the survey zones in more detail. Clicking within the yellow lines of any area will produce a sidebar with a Map Unit Composition, detailing all the different soil compositions that represent that unique area.

UC Davis Soilweb Tate Series

Tate Master Horizon

The experimental farm is: 75% Tate, 10% Unison, 8% Evard, 5% Cowee and 2% French. The Farm is a “TaD” soil series. You can click on any of the blue words for a more detailed soil profile or horizon makeup. Being that the farm is 75% Tate series, we will use that for the basis of our model.

Clicking Tate opens up a new module with many options to explore. At the top there are several hyperlinks. The first, Soil Data Explorer, opens another browser tab with the official description of the profile with descriptions of the master horizons and subordinate distinctions relative to the soil series you selected. Also, all the lab data with many other options. For now, we will not worry about those and focus just on the OSD or Official Series Description for Tate.

Heading back to our soil profiles browser tab we see the other two hyperlinks, Series Extent Explorer, and Description. The Series Extent Explorer will open another browser tab and provide a map with all the areas that feature your soil series, or in our case the Tate series. Description opens in the same ribbon bar and provides just the OSD, or Official Series Description.

There is quite a lot of information presented. The capital letters delineate master horizons (O, A, B, C, E) and the lowercase letters further detail that horizon. Please reference this handy master horizon sheet with detailed information:

Soil Master Horizon Key

(CSU 2020)

Most soils consist of at least three horizons (A, B, and C). For example, our Tate series begins off with “Ap” which stands for a Mineral topsoil that is usually mixed with humus. The “p” means plowed or disturbed soil. Please refer to this graphic for more Subordinate Distinctions Within Master Horizons.

Subordinate Master Horizon Key

(Elements of the Nature and Properties of Soil. 2010)

Understanding the type of soil we are working with can save you lots of time and frustration, and helps you understand how to overcome poor production and perhaps (if you are a farmer) help you be first to market. For now, play around and discover more about UC Davis Soil-web. In another article I will break down the other more complex tool: Web Soil Survey or WSS. Soils is a complex science with lots of information, so stay tuned for more information and we launch into our large okra trial!