Fourth Grade NGSS
Biogeology and Heat Generation

Measuring Heat and Graphing


  • Observing how biological organisms can create heat.change  the environment
  • Measuring heat energy from decomposition.


  • Decomposers
  • compost
  • biogeology



Microorganisms have chemical requirements primarily carbon for energy, nitrogen to build proteins, and oxygen for respiration.  Interacting with these are physical requirements including aeration to maintain optimal oxygen levels while not depleting the moisture necessary for microbial growth. 

Decomposers, such as some bacteria and fungi, get their energy by eating dead organisms.   Individual decomposers are rarely visible without a microscope, but colonies of them (such as bread mold) can be observed.  Decomposers have the ability to break down dead organisms into smaller particles and new compounds, resulting in fertile soil that provides important building materials for plants.

 This decomposition process releases heat.  The generation of heat helps to make sure that the “bad” microbes do not take over and cause harm to humans.   Compost piles have to be large enough to go through this thermophilic process.   Measuring the temperature is very important to make sure it goes through all these phases.


Composting occurs because of the efforts of microorganisms. Although worms and

insects also help, microorganisms are the key workhorses of composting. There are

three major organisms that are important in composting including:

  • Actinomycetes—form filaments and are basically classified as bacteria. They do most of work; larger than bacteria and form networks of filaments. They tolerate low-moisture & low pH conditions.
  • Fungi are best at decomposing woody substances and other decay-resistant materials.
  • Bacteria are small and simple and flourish in the early stages of composting


QUESTION:  How is energy released during composting?

BACKGROUND:  Making compost needs to be monitored to prevent microorganism from harming people.  Compost needs to go through 160 degrees Fahrenheit, 60 degrees Celsius

RESEARCH FOR CLASS: What is soil?  How does compost enhance soil?  What is the carbon to nitrogen ratio in compost?  What do plants need to survive?   How can you improve heat flow?  What if the heat gets too high? 

EXPERIMENTAL DESIGN:  Compost needs to go through a high temperature to get rid of bad microbes.  Moisture is needed to keep the temperature high over 3 days.   Measure the temperature and graph time vs temperature.  Explore how energy is created as a byproduct of organisms feeding on components of food waste.



1.    Per table have students look at dial thermometer.  Point out that outside is Fahrenheit and inside is Celsius.  Ask them what the long shaft is for?  Make sure they understand that it is a sensor and should be taken care of.  We suggest that is stay in the box while not in use.

2.    Measurements will be in Celsius.

3.    Go through the worksheet with have them plot the numbers and have them graph it on the worksheet. With a ruler make an x and y axis.  Then number the vertical (y)as temperature and the horizontal (x) as days.

4.    If students are working on the worksheet, have a small group go out to the Jora compost and show how to read the temperature.  If you have 2 docents this is ideal…or the teacher can stay with the students.





Return to NGSS Model