"Tea time" for science

The Tea Bag Index project is being conducted by scientists and Citizen Scientists worldwide. These experiments help to gather comparable data on a global scale, in particular from regions where no such data has been recorded to date. Citizen Scientists can use this method and  make an important contribution to science and the environment by helping us to understand the global CO2 cycle better. This is simply done by the determination of decomposition rates in different soils with the Tea Bag Index method.

"Tea time" for science

The decomposition of organic material is crucial for the growth and metabolism of plants and microorganisms: decomposition and mineralisation make important nutrients available. Decompostion also releases the greenhouse gas carbon dioxide (CO2) back into the atmosphere. A rapid breakdown leads to increased CO2 emission levels, while slow decomposition increases carbon storage in the soil. Thus, it is of great value to collect more information on decomposition rates in different soils in order to develop a better understanding of the global CO2 cycle.

This Tea Bag Index method can also be used by Citizen Scientists  around the world to make a valuable contribution to science and the environment: they simply bury tea bags in the soil, dig them up three months later and weigh them. The weight loss indicates how much plant material, in this case tea, has decomposed. This simple and cost-effective method for determining decomposition rates in soil is scientifically proven and several scientific initiatives have already been started in many countries around the globe.

These experiments gather comparable data worldwide,so that comparisons between different regions and soils can be made possible.

Countries in which the TBI is measured at present:

About us

Project team

Dr. Judith Sarneel (Umeå University, Schweden/Utrecht University, the Netherlands)
Dr. Taru Sandén (AGES)
Dr. Joost Keuskamp (Netherlands Institute of Ecology)
Dr. Mariet Hefting (Utrecht University, the Netherlands)

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TBI Austria

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Further information

Materials for schools: Englisch
School-experiment in Sweden: ForskarFredag
Publication: Tea Bag Index: a novel approach to collect uniform decomposition data across ecosystems