What’s Beneath Our Feet?

Soil is more than just dirt—it’s a vital part of ecosystems that supports plants, animals, and people. In this activity, Scouts will learn how to test and observe different soil properties across multiple sites. Using scientific methods, they’ll explore pH, nitrogen content, and soil texture, and discuss why healthy soil matters for a sustainable environment.

This hands-on activity is perfect for environmental learning, outdoor exploration, and linking into STEM and Sustainability Special Interest Areas.

What you'll need

• Small shovels or hand trowels

• Soil sample containers (e.g. jars)

• Soil testing kit (including solutions, pipettes, test tubes, and colour charts)

• pH strips

• Distilled or rainwater

• Golf ball-sized samples of soil per test

• Gloves and handwashing supplies

• Notebooks or recording sheets

• Weather-appropriate clothing and closed-toe shoes

 

Testing Methods

To Consider: Why are certain tests and testing methods used? What sort of uses are being considered?

Sample collection:

Before any testing can take place samples of the soil should be gathered.

1. Find a safe location at testing site to collect sample
2. Using a small shovel or similar in an area free of wildlife dwellings to gather a sample of soil filling a sample container (eg: jar) by remove the topsoil (the top 5-10cm of soil) and then using the digging tool extract 1-2 sample containers worth of soil ~250g trying to cause as little disturbance to the surrounding environment as possible.
3. Repeat this in a few more areas taking notes on what the surrounding environment is like in each area (Is the area built up or undisturbed? Is it near a road or housing? Etc.) and label each testing site’s samples eg: sample #1 garden outside of environment center.
4. To prep the samples for testing remove any large twigs and rock and also break up any large clumps to even out the soil consistency.
5. If multiple samples were taken from the same testing site, then all samples should be combine and mixed to create a uniform mixture to average out the testing sites qualities.

 Test 1: Soil pH

To consider-Why would the pH of soil be important? Does it effect the local flora and fauna in the area?

1. Take out about a tablespoon of soil form the sample.
2. Place the soil in an open test tube from the testing kit and add in water (preferably rain or distilled water) slowly with the included pipette of about equal amounts with the soil.
3. After this place cap on sample and optionally mark the test site onto the tube with masking tape and a pen before then shaking gently for one minute to mix the soil and water to create mud (if more water is needed to reach consistency slowly drip in more and then shake further until reached)
4. Allow the test tube to sit for 5 minutes and then dip the pH strip in the solution and leave in slowly stirring it in the mixture for about 30 seconds then remove.
5. Scrape off any of the dirt or debris from the strip to see the colour indicated.
6. Compare this with the colour chart on the packet to determine the pH of the sample.
7. Repeat this with all testing site samples.

Test 2: Nitrogen Content

Soil based nitrogen (NO₃) is an essential nutrient for most plant life for them to grow with increased levels showing signs of healthy soil. Why would it be important to know the nitrogen content in the soil? How might the amount of nitrogen effect the plants that grow in a location? Would this effect the other non-plant species at this site?

1. From the soil testing kit extract 7.5ml from the bottle labeled solution and put in a test tube with 1tsp or ~10g of soil
2. Replace cap onto test tube and gently shake for 1 minute and then allow tube to stand for 5 minutes.
3. Use pipette to extract 2.5ml from the top layer of liquid trying not to disturb or collect any soil from the bottom of the test tube.
4. Transfer into another test tube and add in nitrogen reagent (powder sachet labeled for nitrogen testing)
5. Add cap back on and shake for a further 30 seconds and then allow to stand for 30 seconds.
6. Match the colour of the solution to that of the included colour chart to show the nitrogen levels.
7. Repeat this with the other samples and compare.

 Test 3: Soil Consistency and Texture

How might soil consistency effect the life within and around the soil? Is the amount of water found within the soil effected by this?

1. Take a golf ball sized amount of soil and break up any clumps within
2. Add in some water into the soil to moisten.
3. Kneed for 1 minute to form a consistent dough like mixture.
4. Test texture by pressing ball between thumb and finger pushing the dough out in an attempt to produce a ribbon/line of soil.
5. Once this reaches it limit in length before breaking measure length and take note of consistency to compare to table and determine texture type

Repeat with all other samples. Compare and discuss the effect this might have and what you observed at each site in relation to what soil texture found

Change the challenge level

Easier

• Focus on only one or two of the tests

• Work in teams with adult or older Scout support

• Pre-label testing sites and prepare some equipment in advance

Harder

• Research how soil health affects local biodiversity or agriculture

• Create a report comparing sites with recommendations for improvement

• Extend into a long-term SIA Project with follow-up testing

Reflection