If a scientist is testing the effect of fertilizer on plant growth, which of the following factors would NOT be kept constant?

soil is fertile this is reason that scientists would not be kept constant

Fertilizer

Explanation:

Constants are the parts in a experiment that are kept the same throughout the experiment. Some examples for this experiment could be growing environment, temperature, humidity, amount of water given each day, and the time in the sun.

In this experiment, the scientist is testing the effect of fertilizer on plant growth. Therefore, if the scientist wants to truly test the effect of fertilizer, they would not be able to keep the fertilizer constant. If it was kept constant, there wouldn't be any experiment, because we would use the same amount or type of fertilizer in every trial.

Therefore, the factor that would not be kept constant would be the fertilizer.