If you were designing this experiment for a fertilizer manufacturer, what changes would you make in the experimental design to be confident that your results would be accepted as fact by the scientific community? explain your answer

You have not stated the experiment that is being done here.

I want to believe it is The experimental design and fertilizer applications for organic manures

Explanation:

You need to test some plants in the experiment  more than once. This test needs to be carried out on different plants so as to confirm its importance.

Some factors needs to be considered like the different types of fertilizers available and these need to be tested.

Change the abiotic and biotic factors to determine productivity.