In your experiment to test the hypothesis that a specific type of plant will grow better in soil than in sand, the treatments would be the different growing mediums used for the plants. Specifically, you would have two treatments:
- Soil Treatment: Plants grown in soil.
- Sand Treatment: Plants grown in sand.
By comparing plant growth in these two different conditions, you can assess the effect of the growing medium on the plant's growth. You may also want to control other variables, such as water, light, temperature, and plant species, to ensure that any differences in growth can be attributed to the type of medium used.