Friday, April 17, 2009

Web Soil Survey Information

From In the Garden

I am very lucky to be able to enjoy some nice horticultural classes at a fairly nearby community college. Since this is a garden blog, and since I learn all the time-on here and in life in general, and even in college;-) I thought I'd share a great resource I just learned about in my soils class. Coincidentally, Organic Gardening printed a link to the Web Soil Survey website last spring. I did not make the time to check it out then, but have now and love it! What a boon for our country! Not just for horticulturists, but for builders, homeowners, land owners or prospective land owners, county and city planners, scientists and engineers, as they can all benefit from the Web Soil Survey website.

Anyone who is involved with land and soils in some small way may have heard of the Soil Survey Maps; which are antiquated maps printed in hard copy and consolidated into books. Many of maps in the books date back to the 1800s and early 1900s-and even some of the books date back that far! The information in them has not changed much over the years. In general, soil does not change frequently so the maps do not need to be regularly updated. We all know it takes many, many years for soil to form. In fact, the Soil Science Association says it takes over 1000 years for a single inch of soil to form! Wow! The maps that were once all consolidated in books accessible only through your county soil officer, extension agent, or some other person who has a need for them are now all accessible to you from your home. The maps have all been digitized and put on the web in conjunction with GIS (Geographical Information System) and available in an easy to maneuver format for all. Yes, this is what the Web Soil Survey Website shows in an easy and user friendly manner-and it is all free! Paid for by our tax dollars actually, but free to you-the user!

Jim had David, a soil scientist from Dickson County, come in to give us all a demonstration on how to use the website, lecture about soils and their importance in the grand scheme of things, and in general to share his love for soils with the class. I mean it is a soils class-duh. What's not to love about soils? Everything we plant lovers love rely almost solely on soil and its health. In fact, our whole earth is dependent on soil for life (purely my belief). Remember take care of your soils and the rest will fall into place? Soil-that is the fun part of gardening-digging in and getting dirty. Okay, so I am getting a bit excited here about soil and expressing it a bit much, but this new soil website resource is a wonderful resource! You can pull up a section that includes your house and check out what kind of soils you have there. You can also see: where sink holes and wet spots are located, the depth at which you'll hit bedrock, where your soil came from, what the make up of your soil is, the pH, will your soil support structures or a septic system? You name it and it is there! The system utilizes Geographical Information System (GIS) for its maps, but the soil information was all input by the soil scientists across the country. An amazing feat when you think about it.

David did warn us though that the scale the soil surveys were mapped at do not allow users to go down to single lots. Also, the info is in general since it is impossible to test every square inch of the country for soil data. Additionally, countries who map their soils each have their own system. This USDA map system only works on United States soils. Soils here in the United States have classifications just like plants. They even have kingdoms and so on, we did not go into detail about this part of soils but the maps have a great deal of user friendly reports spelling out all you need to know about your soils.

After arriving home from class I just happened to be on the computer when I decided to pull up my soil map. The rough picture above shows a portion of my town, including my home. The soil line will change depending on the scale you set. I have not sat and played with it in depth, but am satisfied with the information I found on my soils. It is pretty good stuff too. My home rests upon Dickson silt, and I can determine this by decoding the little yellow codes on the map. The website gives you an easy to read legend.

This is what I learned about the soils my home rests upon:

*Dickson silt is loess (blown in material) over clayey residuum weathered from cherty limestone

*Slope: 1-4 %

*Our landform is ridges, and we are on its crest

*Depth to restrictive feature: 18-36 inches to fragipan (altered parent material of soil that restricts water and root growth)

*Drainage Class: Moderately well drained

*Capacity of most limiting layer to transport water: Moderately high to moderately low

*Depth to water table: 24-36"

*Elevation: 800-1200 feet

*Frequency of flooding or ponding: None

*Capacity to hold water: Low

*Silt loam reaches to 45 inches, at which point gravelly silty clay loam takes over

You can also pull suitability reports for building homes, recreation areas, septic systems, and any number of specific uses you may have in mind for your land. There is another feature of the website that breaks down the composition of soils. I found that Dickson soils have a moderate risk for corrosion of uncoated steel and concrete. Dickson soils are also moderately suited for roads in forested areas. The potential of our land for sand and gravel is very poor due to them being on the bottom layer of soil. There are no limitations on my soil if I wished to open a golf course or recreation area. Do you get the idea? It is all fascinating to me and all of my fellow classmates. I bet they went straight home from school and researched their soil like I did mine. Which reminds me, it is late.

Do check out the Web Soil Survey website for some very interesting reading! Not to mention the cool pictures of your home and the surrounding land and vegetation. The commands are very easy to figure out, but I did have the advantage of David showing us the ins and outs. The hardest part will be to set your area of interest, but with the help feature you should be able to figure it out. Don't be afraid to click on all the tabs and explore! Let me know how you like it-okay?

in the garden....digging Dickson silt.

This post is only about the soils and data about soils, but many states and municipalities have GIS; which enables homeowners to pull up property boundaries and pictures and other data. Our local college (Austin Peay State University) maintains it here. Each municipality will vary in its services offered. And of course, there is always Google Earth, a very good GIS resource.

Everyone have a good weekend-I'll be in the garden and not on computers!

Don't forget about Skeeter's coffee set give away! Today is the last day and all you need to do is comment on her Blogiversary post. Go wish her a happy Blogiversary if you haven't already-it could be your name the Saint draws from the hat! She announces the winner tomorrow.


  1. Tina ... that is amazing information girl ! .. I don't know if Canada has that type of mapping but I will take some time to see what I can find .. I gave up entering contests or draws .. I know shipping to Canada is too expensive but I'll go wish a "happy" : )

  2. Well tina, that just took about 30 minutes of 'just looking' at that web site!! It is very interesting! I am glad to have information about my lot in SC. Very useful site. Thanks!

  3. Very interesting information Tina. I will check out that website after work.
    Have fun in the garden...we are supose to get rain all weekend, so I will be inside!
    Have a good weekend!

  4. Morning all!

    Joy, I bet Canada has something similar. In fact, there is an international organization on soil but not sure if your maps are the same. I bet pretty close though.

    Janet, I immediately thought of you when preparing this post. I know I'd want to at least have some basic data about my soil-aside from digging a shovelful out when first seeing the lot!

    Linda, Yes-rain here too on Sunday. Gotta get it all done today-and some housecleaning too:( You have a wonderful day too!

  5. Oh my goodness, Tina, I can't wait to check out my soil on that site! Thanks so much, what a resource! I am going out too, 75 and sunny for today, hooray!

  6. Tina -- what a wonderful resource! My son is an archaeologist and they use soil surveys for the dig sites, too. He is constantly digging test pits in a grid pattern for samples -- while they are looking for artifacts, they "read" the soil to help identify the age of the site and what the land was used for. He carries around soil color cards (can't think of the scientific name) in his kit that helps identify the soil age, type, etc.

    I'll check out the website!


  7. Cool information Tina! I'm headed over there to check our land out!

  8. That was fun! I am playing with it now...There is a downloadable pdf file that gives great instructions! gail

  9. Tina, what a great site. I'll be playing with it for hours. Thanks for pointing us to it.

  10. Morning Tina, I just check the tag on that mottled leafed trillium and it is a Trillium sessile. Very nice plant. I just planted one last year so there is no bloom this year, hopefully next.

  11. Hi Tina, thanks so much for a great article. I also love learning, as you said, even in college classes! ;-) Oddly, I also always learn something new whenever I teach (as i did last night). Thanks so much for the link--I'm so behind in all my magazines, I finally sold two years' worth on eBay a few months back, so i completely missed the link in OG though i do subscribe and do like the mag. Hooray for learning and teaching!

  12. What an interesting blog today! My yard is telling me that i need to plant a water garden right now. come summer, it will be saying water me! lol, I am off to pull weeds and enjoy this beautiful day...

    **Tina, I am not receiving emails right now so if you have emailed me, I have yet to see it. Saint will get this repaired with bellsouth today...

  13. Pretty neat information, I've been to google earth and I'll check out this link later. 60 today, warm and sunny! Kids on spring break! I'm ready to get something done!

  14. VERY interesting. I am going to check mine out now!!!!! Thanks for the info!

  15. It is a great resource Tina ~ thanks for sharing with all of us. I'm lucky to have my own personal soil scientist ~ my dad. That's what he did his whole career, map soils. So I know more about the soil around my house than most people. I'll bookmark this site tho in case I need it down the road.

  16. Thanks for the very informative post, Tina.

  17. Wow. this cyber world is just simply better than the cat's meow!!

  18. I have to check this out. My neighbor was just saying this morning that she thinks we must have been built on a swamp!

  19. WOW, I did not know anything about this info. Thanks so much, Tina. I will for sure be checking it out. I think my home & gardens were built in a swamp. When it's wet, it's wet----when it's dry, it's dry. I was told at one point that it was built on a dump. Radon is a big factor around here. It can seep up through concrete flooring from what I understand. Nasty stuff, can make you very sick.

  20. Interesting stuff about soil! Enjoy your weekend in the garden :)

  21. Our county has GIS online. It's great. It's really neat to be able to see the aerial photographs too.

  22. That is really interesting! I had no idea there was such a thing. I think I will look at ours later on today and just see what they say about it. Thanks for a great post!

  23. Hey all, glad I could show you something new and helpful. I like this site very much. In fact, we were assigned a very important assignment involving it-which reminds me it is due soon! Gotta go. Have a great day everyone!

  24. Very helpful info, Tina. I know my husband has this information about the farm, but I should check it out to know a little more for gardening purposes. Amazing what you can learn from the computer these days!