01 April 2021

Getting to the bottom of Soil Science - Results are in!

Article by Jessica Miller

Getting to the bottom of Soil Science - Results are in!

Year 11 Environmental Science students started off the year with an unusual practical activity designed to highlight the importance of soil health in decomposition rates and nutrient cycling. The students were testing different soil types around the school by burying pairs of new white pure cotton underpants - and then digging them up in two months time.

The activity, inspired by a University of New England challenge called "Soil your Undies" aims to see whether the soil biota (fungi and bacteria) is healthy at a number of locations around the school grounds. Upon excavation, if the undies have holes in them then it will indicate that soil microorganisms have broken down the cotton into special sugars they can use for food.

As you can see the site that had regular watering, nutrients and healthy soil biota in our garden beds produced the most microbial action with the underpants being almost totally decomposed (except for the elastic waist and leg loops). 

The second site was a dry, sandy area at the back of the year 9 building that received no additional watering (other than rainfall) and contained soil typical of the sand dunes of the peninsula. The underpants at this site were almost totally intact with just a few minor holes. A clear and important demonstration of the power of having healthy soil full of microbes that decompose organic matter and recycle waste products in our ecosystems and gardens.

Students were challenged to think about variables that could affect the decomposition rates, methods of testing and comparing sites and possible environmental impacts related to the history and use of the site. The activity prepares students for the field based studies that they will undertake in the local area focussing on pollution and environmental issues and how to monitor and manage them.

Jessica Miller  Environmental Science teacher