I’m not exactly sure how it ended up this way, but it appears that one of my pastimes is playing around with freely available GIS tools.
While it may be a tad clunky in a few ways, the Web Soil Survey application provided by the United States Department of Agriculture can provide a lot of value to a wide variety of people. So, let’s dive in: this post will go into great detail as to how regular people can get great value out of this humble little tool.
Who Should Be Interested in This Application
I’m not going to lie: this will end up being a pretty long post, with many, many screenshots. The truth is that this kind of post won’t be everyone’s cup of tea, and that’s totally fine. There will be a few slightly technical parts of this post, but we’ll leave the vast majority of the technical stuff for the scientists.
So, let’s cut right to the chase. Here are some real life scenarios that this tool is very well equipped to help with:
- Identifying the locations where you’re more likely to find a certain native plant growing (foragers, I’m talking to you)
- Finding a list of recommended trees to plant for your specific type of soil
- Being able to quickly assess the soil type and other soil information regarding a prospective land purchase
- Discovering the approximate height a specific tree would reach at maturity on your soil
- Comparing the yearly rate of wood production for different tree species on different soils
And so on. If any of those ideas are interesting to you, this post should help get you started with the Web Soil Survey application.
Making Sense of the Screen Before We Dive In
Before we start clicking around and navigating all over this thing, I think it makes sense to quickly cover a few aspects of how this is setup. It really isn’t too unique of a setup, but there are a few quirks.
Important: Notice the Tabbed Setup at the Top
The first thing you should really notice is that there is a series of five tabs over the top of the screen. You’ll see these tabs highlighted in the screenshot below:
We’ll cover this in more detail later, but understand that this tool is setup for us to navigate the tabs from the left to the right. In other words, we can’t move on to the ‘Soil Map’ or ‘Soil Data Explorer’ tabs until we’ve specified our Area of Interest (AOI).
The AOI is exactly what you think it is: it merely gives the tool a specific area of land to run the reports on. Many of these reports pull in a lot of different information, so they could be quite computationally intensive if we didn’t have to narrow our focus.
Navigating the Map With the Toolbar
It might look like there’s a lot going on with the toolbar, but there’s really only two things that we’re going to focus on: defining you AOI and moving around the map.
First, defining your Area of Interest simply requires that you activate on of the two following buttons:
The square button on the left allows you to select a rectangular AOI, while while the right button allows you to get creative and create your own polygon AOI. Pretty straightforward.
Regarding how you move around the map; I have some bad news here. The unfortunate reality is that we’re going to have to go back to the days of MapQuest. Remember them?
What I’m trying to say is that you won’t be able to move the map or adjust the zoom with merely a dragging click and the scroll of your mouse wheel. Here we’ll need to have the zoom in button activated to zoom in, and we’ll need the same for zooming out.
Moving the map around by dragging is possible, it’s just that you’ll need to first activate the pan button (the white glove) and then you can pan.
You do have the ability to zoom in to a specific area by dragging a box over it while the zoom in button is toggled on. Still, in order to zoom out you’ll need to click individually to back further and further out. Just expect a bit of a retro experience and you’ll be fine.
Information and Reports are on the Left Panel
You’ll notice that the left side of the screen contains a section where you can find a variety of reports or additional layers to include. Here’s what I’m talking about:
Depending on which tab of the tool you’re currently in, this section will display what is available to you. The available reports and layers may vary based on the AOI that you choose, so be aware that things are a bit flexible.
You can expand and then collapse a section by clicking on the downward arrow buttons on the right side of the window. When you expand a window you’ll possibly encounter buttons or drop-down menus relevant to your section. Understand that the map will not change until you click one of the buttons associated with the section.
Here’s an example: if I want to add a layer to the map showing the Headwaters Wilderness are in Wisconsin I’ll need to find it with the drop-down menus and then click one of the ‘View’ buttons like below:
Again, this is easy enough, but it might save you a little time and frustration if you don’t have to discover this one entirely on your own.
Results of a Report Show Up Below the Mapped Area
Until you run a report on your AOI there won’t be anything under the mapped area. However, as soon as you run a report you’ll be able to scroll down and see the table of information that corresponds to that specific report for your AOI. Below is an example of what I mean:
Scroll to the very bottom and you’ll likely get a box of information that provides background on the report that you’re seeing. Here’s an example of what you might expect:
This section is actually really helpful and I’d strongly encourage you to get in the habit of scrolling all the way down to the bottom before digging into your results table. Taking a little extra time to learn about what you’re seeing may save you some time on this journey.
Basic Overview of How It Works
Now that we’ve covered the anatomy of the screen, it’s time to start talking about how this tool actually works.
Define Your Area of Interest (AOI)
As discussed briefly above, your job when defining an Area of Interest is to tell the tool which land you want soil information on. Before we designate an AOI, there are two important things for you to keep in mind:
- AOIs are limited to 100,00 acres in size
- It’s possible that you’ll define an AOI that requires two different soil data sources
In either case you’ll be notified with a popup window stating as much.
To define your AOI you’ll first need to verify that one of the last two toolbar buttons are activated, like so:
Next, you’ll click and drag your mouse to define a region to set as the AOI, like this:
After your AOI is selected you should have a map with a box that has diagonal lines running across it, like so:
At this point you’ve selected your AOI, but you just haven’t done anything with it.
Switch to the Soil Map Tab to Pull Up Your Information
Now that you’ve found your AOI, we’re going to turn that box with horizontal lines into an actually beneficial map.
To do that we’re simply going to scroll back up to the top of the screen and click on the ‘Soil Map’ tab, which is the second tab. This should change our map into something like this:
Success! Hopefully you’re now starting to get a better picture of what’s going on here. Just to pull up a map that’s a little less intimidating, here’s a section of the above area where I’ve zoomed in:
While they may look like jibberish at this point in time for you, each of the symbols on the map corresponds to a unique type of soil. For example, there’s a puzzle-piece shape of soil on the left side with the ‘VsD’ label. If we scroll down on the window on the left, we’ll find more information about what type of soil this is:
You can click on the link in order to bring up a window with more information on this specific soil type, but I think most of that data is a little too scientific for our needs. If you’re a gardener you may already have some familiarity with what ‘loamy sand’ could represent, but others don’t need to worry.
Soil Data Explorer: Tabs Within Tabs
We’re really playing with fire now that we’ve made it to the ‘Soil Data Explorer’ tab. This is where all the magic happens. Congrats on making it this far!
There’s a lot of different things going on here, but here’s what you need to know: you’ll now see that we now have a second layer of tabs underneath our original tabs.
I’ll go through each of the tabs in sections below.
Intro to Soils
This tab is mostly useful if you’re looking for more in-depth explanations about what many of these things mean. They have the educational content split apart nicely, it just happens to be a bit of a pain in the butt to navigate.
Either way, you’ll be able to check the boxes of the sections you want to show, and then click the ‘View Selected Topics’ button to update the screen. Feel free to come back to this section if you’ve decided that you would really like to develop a better understanding of soil science.
Suitabilities and Limitations for Use
Many of the reports in this section are geared towards commercial operations like construction companies and large-scale farming operations, so you’ll likely be able to skip over most of this.
There are, however, a few interesting areas that average people might be able to make use of. As there are a million reports found throughout the menu, I’ll just list the menu groupings in this tab that appear to have some value:
- Land Management
- Soil Health
- Vegetative Productivity
Soil Properties and Qualities
There’s no way around it: this section’s for the scientists. Short of you having a degree in soil science, you can feel free to skip over this section and move onto the actually valuable stuff.
Soil Reports: Full of Useful Information
Last and certainly not least, we’ve finally arrived at the tab that can provide the most value for the average person.
There are a ton of really valuable reports that you can find in this part of the tool. I could spend a bunch of time going over all of the different options, but I think the best choice is to cover all of the best reports in the following section.
Download Soils Data and Shopping Cart
I think it’s nice that the tool allows for you to download soil data and prepare a custom report on your Area of Interest, I just don’t know if most people would get any value out of them. Both of these areas are quite self-explanatory, but I think they are more tailored to the academic types.
Practical Examples of How to Use This Tool
We’ve gotten past the boring how-to and we’ve arrived at the part of the post where I actually get into the good stuff. Let’s find some practical applications for all of this!
Finding Common Understory Vegetation for Forests
Without a doubt, this is my favorite application of this tool. I think there’s no reason to hide it, I love bumming around the woods looking for new edible plants to identify and learn about.
What you can do with this is identify which types of plants occupy the understory of a forest. Here’s where we can find this report:
- Go to the ‘Soil Reports’ tab in the ‘Soil Data Explorer’
- Expand the ‘Vegetative Productivity’ report group
- Find the ‘Rangeland and Forest Vegetation Classification, Productivity, and Plant Composition’ report at the bottom
- Click the ‘View Soil Report’ button to generate your report
Once the report has loaded you’ll have access to a variety of data fields associated with each soil type. We’re only really focusing on one field here, the ‘Characteristic rangeland or forest understory vegetation’ field in the middle.
What’s the best way for a forager to think about this in real life? Here’s how I approach it: I establish my AOI as a nearby area with a lot of public land that I’m interested in foraging in. Once I set my AOI, I can just skip right to the ‘Soil Data Explorer’ tab and run the report that I need.
Here’s about what my screen will look like once I’ve done all of that:
Admittedly, there’s a lot going on in this screenshot and it might take a bit to process. Just from the maroon colored tabs and report at the bottom, you can quickly get a good idea of where we are in this tool. The map shows the soil types for our entire AOI, and the section below that is where our report outputted. Towards the right of the report you can see the ‘Characteristic rangeland or…’ section: this is the column that we will be interested in.
This screenshot is a good example of what you can hopefully expect to see included in this report:
At the top you’ll see an arrow pointing to the ‘MnB’ part: this is the specific soil type that this is information is related to. Below that you’ll see an arrow pointing to ‘Menahga.’ Menahga happens to be a family of soil types, and MnB happens to be a specific variety of that soil. As you may have guessed, the ‘Mn’ portion of the MnB name is shorthand for the Menahga soil family. The ‘B’ portion simply refers to the degree of slopes found in this area, which makes sense once you see the ‘0 to 6 percent slopes’ portion of the soil type description above.
Now it’s time to get to the good stuff: the box on the right is pulling in a list of plants that are commonly associated with this family of soils. Right off the bat I notice the following values:
Having learned that this family of soils may have these types of wild edibles present, my next job is to go back to the map and look for Menahga soils. Like I mentioned before, the ‘Mn’ portion of the MnB soil type stood for Menahga, so I know that I can be on the lookout for each of the following soil types when I go back to the map:
Just a quick side note before we get back to the report: it seems like the Xx[A-D] soil naming convention is used in a variety of locations. What you may want to internalize is that the A-D portion refers to the severity of the slope, with D being the steepest grades.
Going back up to the map, if I zoom in I can see the following area with ‘MnX’ soil types:
Now that I’ve located areas that might have some interesting types of wild edibles, my next job is to confirm whether or not this is public land that I have access to. This is a topic for another post, but it still is a very important step.
As you might be able to figure out, this can end up being a very valuable way for a forager to take a more targeted approach when looking for wild edibles.
Now, here comes the caveat: while I’ve had a good amount of success with these reports, I wouldn’t expect to walk into an absolute paradise of wild foods every time you use this. I’ve had many times where I got skunked when looking for something that the report mentioned, so be sure to go in with the right expectations.
I’ve had success using this approach with both mature forests and young forests taking over recently disturbed lands, so be sure to keep an open mind and lace up your hiking boots. You’ve got some hiking to do.
Identify Which Trees Might Be Present
The next report that we’ll be going over is a great way to get a decent idea about which native trees may be present on that type of soil.
This report is found in the same location as the last one, so all you need to look for is the ‘Forestland Productivity’ report in the ‘Vegetative Productivity’ grouping. Having navigated to that report and executed it, this is what my screen looks like:
The information from the report that we’re most interested in is found in the highlighted group at the bottom of the screenshot. We’ll go over each section to give you a decent idea as to what they mean.
Here’s an example of what you might see for results in the report:
Just like the last report, you can tell that the structure is that the data is associated with the name of the group of soil types (Pence in this case), and that the specific soil type is ‘PkC.’
The next column over, which refers to the ‘Common trees‘ heading, is the information that I find most valuable for my purposes. This is a list of the types of trees that you can expect to find associated with this soil type. So if I was interested in finding out where a specific tree may grow, I would use this report to start to narrow down my locations.
The following column is the ‘Site Index‘ and this is where you might see some numbers that are associated with the tree listed to their left. What does this mean? Basically, the site index in this report gives us an approximate height (measured in feet) that a tree is expected to reach after a certain amount of years. I think the length of time may vary, but you can expect something like at least 50 years. Obviously, how tall a tree can grow after X number of years is highly variable depending on a lot of other factors (light, competition, etc.). But this can still be a great way to quickly understand how suitable a certain type of soil is for a specific tree.
The last two columns can provide some interesting information, but I think they’ll mostly just apply to someone trying to manage a forestland for productivity. The column with the numbers in it is the ‘Volume of wood fiber‘ and this is an approximate measure of the volume of wood that an acre those trees would produce in a year. According to the notes below the report, that number is measured in cubic feet per acre per year. The last column is the ‘Trees to manage‘ section, which just mentions what kind of trees are worth promoting if you’re managing a forestland for lumber production.
Planting Suggestions for Bushes and Trees of Varying Heights
This report is also found in the same group as the prior two reports. You’ll want to find the second report in the ‘Vegetative Productivity’ group, which is the ‘Environmental Plantings and Windbreaks’ report. Expand that report open and click the ‘View Soil Report’ button, and your screen should look something like this:
If you look at the headings highlighted in the bottom portion of that screenshot, you’ll notice that this report is laid out rather simply.
First, you’ll have to find your soil type, but once you do you’ll hopefully see something like this:
Like the previous two reports, you can see that the information is tied to the Menahga soil family, which is being pulled in from the MnC soil type.
Here’s what’s so valuable about this report: this is an incredibly easy way to find ideas on what kinds of trees and bushes to plant while having an understanding of how they will develop over the next 20 years.
Unlike the site index metric from the last report that talks about how tall a tree may grow after a 50+ year time frame, I feel that a time frame of 20 years is a lot more approachable for a landowner.
This tool also helps you plan for the different layers that you might find in a less mature forest. Overall, I find that this layout is very handy when trying to develop a picture in your mind about how your land might look with enough time.
In-Depth Information on Suitability of Soil For Grape Production
This last one is just for fun, although I know that some people might be able to make use of it.
First, we’ll need to navigate back up to the second layer of tabs, and we’ll need to switch to the ‘Suitabilities and Limitations for Use’ tab. Then we’ll need to expand the ‘Vegetative Productivity’ tab and find one of the reports with ‘American Wine Grape Varieties Site Desirability’ at the beginning of the name.
The area I’m exploring shows four different options, ranging from short to very long. I’ve selected the ‘short’ option and this is what I see in response:
There are a few things to notice here. First, you can see that the map has added a color hue used to indicate how suitable that type of land is for growing grapes. Obviously, red areas correspond to land that is generally unsuitable for growing grapes. Looking at the screenshot above and being familiar with this area, I can tell that the red areas here represent swampy land or creeks.
The other thing to notice is that the report below the map contains a column entitled ‘Rating reasons.’ This is the part of this report that contains the most information about growing grapes, but this column is very well organized. If you scroll down to the report you may see something like this:
There are a few things to take note of here. First, notice that the soil types are organized a little differently this time around. The report is still organized by the specific soil type (PkC in this case), but that soil type now has information on composition. While the PkC soil type mostly consists of Pence soil, it also has Padus and Sayner soil present. Most people won’t need to worry about this, but it helps make sense out of the highlighted information.
Secondly, you’ll notice that the third column simply has the word ‘High’ in it. This is the overall suitability rating assigned to the PkC soil type, so this states that this soil type is highly suitable for growing grapes.
Last but not least, you can see that information in the highlighted column has numbers present. These numbers fall between a score of 0 and 1, with a higher score indicating that this type of soil is better suited for this purpose. You may notice that only the ‘Site and soil features’ number varies between the different soil classes, as the ‘Growing season length’ and the ‘Slope’ are independent of the soil class.
There are a variety of similar reports in this tool, as much of the functionality is geared towards helping people use their land for the most effective purposes. How effective land may be towards an application like growing grapes depends greatly on your soil. Obviously, it’s much easier for land owners to leverage a tool like this that is provided for free by the USDA, when compared to the alternative of learning everything you can about soil science.
If you are interested in learning more about how reports like this work, your best place to start is at the bottom of the screen below the report results. Here is what that looks like for this report:
While the description section might get a little technical at times, I’ve found that it’s almost always written in friendly-enough language.
I know that post was a bit of a doozy, but I hope you were able to follow along and you managed to get some value out of the experience. I just can’t help myself, I love taking the time to dig into these undervalued reports and find little nuggets of gold.
If you enjoyed this piece and you’d like to see what else is possible with freely available mapping applications, feel free to check out the below article: