• What other experiments would you need to conduct before you make a decision about the use of biochar? How would they
help you make a better-informed decision?
I would need to do the experiment with different plants and soils. I would also need to try the same experiment on dry soils because
other experiments show that biochar can keep soils moist in dry conditions.
• Provide two new questions you have since completing the experiment and analyzing the class data.
Why didn’t the biochar increase plant growth in the sand? Sand isn’t very fertile and I thought the biochar would help add nutrients
that would make the plants grow better. Why do plants grow more roots, but not more plants, in sand than in potting soil? If the
sand is less fertile and the plants need more roots, how are they able to still grow the same amount of leaves?
Appendix 3. Example data table worksheet for plant growth experiment. Data tables will differ for the soil respiration
experiment depending on the data collection device used.
Student names: __________________________________
Date of planting: _________________________________
Date plants broke soil surface: _____________________
Soil Type Treatment
Mass (g) Root : Shoot