Soil temperature affects climate, plant growth, the timing of budburst or leaf fall, the decomposition rate of organic material, and other biological, chemical, and physical processes that take place in the soil.

How do flowers and other plants know when to start growing in the spring? How do farmers know when it is safe to plant their crops? Soil temperature plays an important role in both of these decisions. Each spring, soil is heated from above by warmer air and by solar radiation. Once the soil reaches a certain temperature, it is time to plant and grow.


In the Preliminary Activity, you will gain experience using a Temperature Probe and learn soil temperature measuring technique as you determine the temperature of a soil sample.

After completing the Preliminary Activity, you will first use reference sources to find out more about soil temperature and factors that affect it before you choose and investigate a researchable question dealing with soil temperature.