The tea bag index provides a highly standardized reference method for any decomposition study. We use Lipton Green tea and Rooibos tea that comes in plastic mesh bags, and bury them for 3 months at 8 cm depth. Next to using tea as a standard litter, you can use the weight loss of green tea and Rooibos tea to calculate two decomposition parameters, by which you can fit a two phased decay curve. The details of this are explained in our publication in Methods in Ecology and evolution (Keuskamp et al., 2013).

This website contains details on the method, tips and tricks and the ways to obtain tea under ‘method’. Be aware that the method described here is somewhat simplified to address a wider public. A more extended protocol can be foundbg_teabags-table as a download at the method page.

The method has been successfully used to obtain measurements along gradients and to test experimental treatments in greenhouse potting studies and mesocosms. Researchers are challenged to test the usefulness of the method in their own scientific set up. As it a relatively new method, we are keen on learning from your experiences.

Our goal is to create a global soil map of decomposition and we are very close to finalizing this. That does not mean that we do not welcome new data. We envision that this portal will be the collection point for all existing tea bag data (woven and non-woven). This database will hopefully inspire many interesting research questions.

On this website you will find the standardized excel sheet that will help you to calculate the TBI parameters. This file can also be uploaded into our database under ‘submit multiple datapoints’. You can also use this database as data repository. The datafile will remain yours, and you can set the level of visibility. Please get in contact with us if you want to use it as such.

We also welcome projects that want to use the TBI database for answering specific questions.