Tea bags

What is the Tea Composition project?

5 December 2018
We're using the humble tea bag to analyse soil health across NSW
You might be wondering why we care so much about soil. Soil is an essential, complex and highly valuable natural resource which we depend on to produce the vast majority of our food, fibre and economic sustainability.
Tea bags

Our researchers need the help of students and teachers to develop a digital map of soil health across New South Wales. The Tea Composition project is an exciting initiative that is based on the Global Tea Bag Index. The Tea Bag Index provides a simple method for students to conduct this research. Here we learn all about climate change research and how the community can participate in this global experiment.

Why do we use teabags?

To determine whether the soil has a healthy microbial community that can decompose organic material, we need to provide them with something to decompose.

Teabags make wonderful candidates as the organic material is contained in the teabag. This makes measuring differences in decomposition easy. In addition, the material of the teabag allows air, water and the microbes adequate access to the tea.

In the Tea Composition project, we have followed a standardised methodology called the Tea Bag Index. In this methodology they use green tea and rooibos tea bags. A key difference between the two is that green tea breaks down easily while rooibos takes longer to decompose. The relationship between these two teas will tell us about the decomposition rate and stabilisation of the soil.

The process

  1. Students will choose at least two different locations on their school grounds, for example, a native environment and a managed environment (i.e. sports field)
  2. The students will weigh and bury rooibos tea bags and green tea bags in each location
  3. Students will conduct a range of field, classroom and laboratory analyses on each site to determine soil and environmental properties such as organic matter, pH, clay content and vegetation
  4. After three months, students will exhume the tea bags, dry, weigh and determine the rate of decomposition, and in doing so, examine the microbiological activity of their soils
  5. Students can also have their soils analysed at The University of Sydney, where detailed digital interpretations of their soil properties will be supplied in return
  6. Online lectures and discussion forums will allow students to interact directly with leading soil scientists about their project.

Get involved

Participation in Tea Composition aims to develop students’ experimental, analytical and communication skills by meaningfully performing an actual science research project. Students will develop connections with scientists at The University of Sydney and school groups around NSW through knowledge exchange, mentoring and expert advice.

Learn more on our official TeaComposition webpage.