Soil your Undies: measuring soil health with underwear

Soil your Undies is an experiential test of microbial activity in soil. Students learn the biology of different soils by burying 100% cotton underwear. Soil your Undies meets Grade 3 and 7 learning outcomes but can be adapted for any grade level.

Soil Your Undies is a campaign developed by the Innovative Farmers Association of Ontario and spread nationwide by the Soil Conservation Council of Canada. By burying pairs of 100% cotton underwear in different kinds of soil and comparing decomposition rates, students can draw inferences about the rate of soil biological activity.

One teaspoon of healthy soil contains more microbes than there are people on the planet. These microorganisms play a critical role in developing soil structure, making nutrients available for plant uptake, and decomposing plant residues. However, tillage, excessive fertilizer and pesticide use, soil acidity, and other factors can destroy microbial communities, resulting in unhealthy soil. Soil Your Undies is a fun, hands on way to test soil biological health. Simply bury the underwear in the soil and check back 60 days later – if nothing is left but the elastic band, the soil is healthy.

Healthy soil supports sustainable food production, enhanced biodiversity and cleaner air and water for present and future generations. Teachers can use Soil Your Undies to create opportunities for learning while meeting Science outcomes for Grades 3 and 7 and other grade levels.

Soil your Undies kits include:

  • 100% cotton briefs
  • instruction sheet with links to online resources
  • staff support to answer questions

This program is available throughout the school year.

Teachers should take into consideration that:

  • underwear should be buried for at least 2 months (preferably not during the winter months when microbes are less active)


Teachers in public schools are eligible to apply.

How to apply

  1. Determine if the Soil your Undies Kit is a good fit for your classroom.
  2. Complete the application form.
  3. The Department of Agriculture will review all applications.
  4. Teachers will be contacted with delivery details.

How long it takes

Teachers will be notified within 5 business days that their application has been received. Teachers will be contacted with delivery details.


There is no cost to participate in this program.

Before you apply

Make sure you have at least one location on the school grounds where you can bury the underwear.

Important dates

This resource is available anytime throughout the year.

Apply online

Start now

Contact Information

Agricultural Education Office
74 Research Dr.
Bible Hill, NS B6L 2R2

Phone: 902-893-6575