Testing Soil Texture by Hand – The Soil Ribbon Test


Have you ever wondered what kind of soil you really have? Ever wondered where it really fell on the NRCS soil pyramid? Or are you looking to select the perfect spot for a vegetable garden, and can’t choose between two sites? Well, I’m about to show you a test that will tell you definitively what soil you have, and the best part is that it only takes 5 minutes to perform. [1]

The soil ribbon test is a fast way to remotely assess soil type in the field. By knowing the ribbon length and texture, we can approximate if the soil is clay, sandy, or loamy – and how it will drain and hold nutrients. This test only requires some soil, water, and a tape measure to perform.

Materials

  • Shovel or trowel
  • Tape Measure
  • Spray bottle with water

Process to perform the Soil Ribbon Test

1 – Gather a soil sample. Collect a sample of the soil you wish to test by taking a handful of soil from the top 4-6 inches.

2 – Wet the soil. Spray a small amount of water onto the soil. Start trying to form the soil into a ball. Keep adding water until you are able to do so.

*Note – if it is not possible to form a ball, then it is likely that you just have sand for soil.

3 – Knead the soil sample. Work the ball in your hands, similar to kneading dough. Remove any bits of organic matter (leaves, stems) and any small pebbles.

Keep working the ball of soil until no dirt sticks to your hand. It should feel similar to silly putty or play dough.

4 – Make a ribbon. Start to form the ball into a ribbon by squeezing it in your hand like you would hold a staff or handle. Press your thumb so that a ribbon begins to form, extending out over your index finger.

As the ribbon grows, move the mass of soil up in your hand, and press your thumb to continue forming a ribbon. Keep doing this until the ribbon breaks.

5 – Measure the ribbon length. By measuring the ribbon length, record this.

*Note – I often will make several ribbons in my sample area. This way I can ensure that there is no random pebble or piece of wood that causes a ribbon to break prematurely.

6 – Check the texture and feel of the soil. Take a small piece of the ribbon, about the size of a pea and place it in the palm of your hand. Add a significant amount of water to the soil so that it becomes fully saturated or over-wet.

7 – Rub your index finger on the soil sample. Press your finger on your palm and rub in a circular motion so that you can really feel the soil texture.

At this point, you want to classify how the soil feels into 3 categories:

  • Gritty – A gritty texture has the sensation of rubbing dried sugar or sand between your fingers.
  • Smooth – A smooth texture feels like rubbing flour between your fingers
  • Neither – If neither gritty nor smooth texture dominates

8 – Determine the soil type by comparing it to the Matrix Key. Check the combination of soil ribbon length and texture against our Soil Texture Matrix. By using the rows as classified by ribbon length, and the columns classified by texture, you can determine the soil type. This is comparable to the NRCS soil texture pyramid.

A soil ribbon that is less than 1″ in length is typically sandy or silt loam with minimal clay content. A ribbon that is between 1-2 inches long is loam. A ribbon that is longer than 2″ long has a heavier clay content.

If you cannot form a ribbon, or a ribbon is less than 1″, it is Sandy Loam. Otherwise, match up the row and column to your sample!
From US Dept. Agriculture, NRCS [3]

Please watch our short video demonstrating the test!

How accurate is the ribbon test?

The ribbon test will match the correct zone of the NRCS pyramid if the test is performed correctly. It will not tell you precise proportions of sand, clay, and silt. To do that, I recommend that you perform the Mason Jar Test for Soil Texture. As the mason jar test is very accurate, and simple to perform.

I personally have collected soil samples and performed both the ribbon and mason jar test, and found the results to agree with each other. It does help to make more than one ribbon though, as more samples will yield more accurate results.

Do the results of the ribbon test indicate how well my soil will drain?

The results of the ribbon test will inform you about how well your soil will potentially drain.[2] In general, overly compacted soil will not drain well. So, after you’ve selected the area to build a garden, you should really consider testing the drainage of your soil. It doesn’t take too long, and really informs you as to the nature and state of your soil.

To improve drainage, you should consider amending the area or top dressing with compost. As the compost will significantly reduce compactions and allow better infiltration of water.

We really have an excellent guide on how to make a compost pile. We explain it in the simplest, most bare bones terms. Too much of the internet and YouTube over complicate the simple art of making compost. Please have a look and tell us what you think:

References:

[1] – Arshad, M. A., Birl Lowery, and Bob Grossman. “Physical Tests for Monitoring Soil Quality.” Methods for Assessing Soil Quality methodsforasses (1996): 123-141.

[2] – D. Whiting, C. Wilson, and A. Card1 Estimating Soil Texture: Sandy, Loamy or Clayey? no. 7.723. Colorado State University, Cooperative
Extension

[3] – United States Department of Agriculture, Natural Resources Conservation Service.

Joe Foster

Hi - I grew up outdoors in nature - hiking, fishing, hunting. In high school I got my first job at a garden center where I learned to garden and landscape. I've been growing plants from seed and designing native plant gardens for over six years. I hope to share some of my knowledge with you! Additionally I am a wood worker / DIY enthusiast. I enjoy designing/building projects (with hand tools when I can!). I hope to give you some tips and useful information!

Recent Posts