Respuesta :
Answer: It's an EXPERIMENT
Explanation: Experiment is done when we apply anything to a samples or conditions in other to study another sample or conditions.
Observation is done when, we study samples or conditions in it's natural way, without application of anything that may alter it's result.
Because the researcher has applied fertilizer to one side and did not apply to the other side, that means he has performed an experiment. Since he wasn't observing the two sample in it's natural way without any external application.
Answer: This was an EXPERIMENT.
Explanation: An experiment can be defined as an examination under inhibited conditions made to examine the validity of a hypothesis, demonstrate a known truth, or determine the efficacy of something that has not been tried before.
In this question, the researchers applied the fertilizer to some parts while they didn't apply to some other parts. This act, is a quality of an experiment in the sense that the test was done under inhibited conditions. If the fertilizer was applied everywhere, it can be an observational study.