Soil Judging Resources


Soil Judging is the best experience undergraduate students can get in the field of soil science. My goal is to make Soil Judging more approachable by providing resources and information that can be used by Soil Judging Teams, both new and established.


Contents:
1. Moist rupture resistance/consistence hand calibration 
2. Activities related to soil texture
       -  Guides for teaching soil hand-texturing 
       -  Real life texturing - fun activity for when your field day is rained out
       -  Visualizing the soil texture triangle
3. "PizzAbundance" estimating activity


Calibrating your hands for moist rupture resistance/consistence
Reference: Schoeneberger, P.J., D.A. Wysocki, E.C. Benham, and Soil Survey Staff. 2012. Field book for describing and sampling soils, Version 3.0. Natural Resources Conservation Service, National Soil Survey Center, Lincoln, NE.  

The Field Book for Describing and Sampling Soils ver. 3.0 (Schoeneberger et al., 2012) defines rupture resistance as “a measure of the strength of soil to withstand an applied stress.” It is estimated in the field as “the force required to rupture (break) a soil unit” which fall into the following categories: 
Here is a method for use standard samples to learn what some moist rupture resistance classes feel like (plus it's delicious). We determined these based on the force required for rupture resistance classes at the moment the candy or cookie starts to give/break. Make sure to treat all snacks like blocks (crush horizontally, not vertically) and do this activity at room temperature. 
[Picture]
Although Junior Mints are shaped more like plates, for the sake of this activity treat them like blocks.
Hand-texturing soil

1. Guides 
I've been working on these hand-texturing guides for many years. Many of these tests (and some of the photos in the documents!) I learned from Dr. John Galbraith at Virginia Tech.
Introductory guide
Advanced guide

2. Real life texturing -  An exercise for connecting textures to everyday(ish) items 
We set up bowls of these: 
  • Kinetic sand 
  • Silly putty 
  • Play doh 
  • Flarp 
  • Modeling clay 
  • Oobleck (corn starch + water) 
  • Flour + water 
We tried to find soil samples that were similar in texture to those above; for example, kinetic sand is pretty similar to a loamy sand texture. 
 3. Visualizing soil texture
Use masking tape to create a texture triangle on the floor, tarp, lab bench, etc. Then, place known soil textures where they belong on the triangle. I have found that this helps the students understand how the triangle works, as well as helping them visually connect what they're feeling to each texture class. You can also do the reverse: quiz the students by giving them texture samples and having them place the samples on the triangle.
"PizzAbundance"
An exercise for learning and practicing abundance estimation in soils

Summary: Order pizzas with different combinations of toppings and have your students estimate the abundance of each topping and decide on a modifier before eating well-earned pizza. 
1. First, categorize possible pizza toppings, for example: 
Gravels = sausage, beef, bacon, olives ( we made the executive decision that olives are gravels and informed our students)
Channers = pepperoni, ham, salami, mushrooms, green peppers, spinach 
2. Formulate & order the pizzas with different combinations of toppings
We expected 15 people, so we ordered 4 medium pizzas, including a vegan and veggie pizza, and a range of difficulties for abundance estimation:
(A) Pepperoni
(B) Green peppers + olives
(C) Sausage + ham
(D) Olives + mushrooms + spinach (no cheese)
Tip 1: Avoid similar-colored toppings, such as bacon + ham
Tip 2: Combine gravel and channer toppings for more difficult estimation 
3. Go through the PizzAbundance presentation with the students
Tip 1: Keep the pizzas secret until the end of the presentation
Tip 2: If you have photos of rocky soils, those would be a great addition
Tip 3: Try to keep the presentation short so the pizza doesn’t get cold! 
4. For each pizza, have the students give: (1) size, shape, and % rock fragments for each topping (2) Total %RF (3) RF modifier, if necessary, using the correct abbreviations 
We labeled the pizzas A through D and spread them around the classroom. Each student wrote 1-3 for each pizza on their own paper. For example: 
Pizza B:
1. Channers (green peppers) 25% 
    Gravels (olives) 15% 
2. Total: 40% RF 
3. VCH (very channery) 
Tip 1: This is a great chance for students to apply the rules for rock fragment modifiers (e.g. for a mix of sizes, the largest size class is generally named) 
Tip 2: Keep in mind that you will not be able to predict abundance ahead of time. We decided that my estimations, with input from assistant coaches, would serve as our answer key. It turned out that all our pizzas were dominated by channers 
Other modifications: 
Adapt for estimating abundance of secondary carbonates or redox features: 
  • Reddish toppings are concentrations (e.g. pepperoni) 
  • Grayish toppings are depletions (e.g. mushrooms)
  • Cheese is a depleted matrix 
It’s best to connect this to actual field estimation as quickly as possible!