Investigating Soil Decomposition

Earth ecoSTEM Kit Materials Used: Tea Bags and Pocket Scale

ENGAGE - Students Observe This Phenomenon


GATHER Energy Investigations


graphic organizer summarizing the learning process of this activity

EXPLORE a Kit-Supported Learning Experience

Students will weigh, bury, dig up (after 60-90 days), dry, and re-weigh tea bags.  Note that Lipton no longer makes the green and rooibos teas in pyramid bags specified for the Tea Bag Index citizen science project, so students will design and do an investigation to compare  the decomposition rate of Forest Fruit tea in different types of soils, by modifying this protocol.


Students should be able to explain that decomposition is the process by which the nutrients in plants (and in animals) are released to the soil through death and decay of that plant, which provides a source of nutrients for other organisms growing in the same soil.


Students may submit data to the Tea Bag Index citizen science project if they can find Lipton green and rooibos pyramid tea bags to use (though they are discontinued). The purpose of the project is to use decomposition rates to create a proxy soils map of the world.


Students can design and conduct tests to discover the impact of flooding, fertilizers, and temperature on decomposition, and use the results as evidence in constructing an argument about how climate change may influence decomposition rates.



After making sense of a core idea by engaging in science or engineering practices through the lens of crosscutting concepts, students revise their original explanations of a phenomenon.


Students may propose solutions to poor soils and choose a project to do, such as amending soils to improve drainage.