Question

what was the drawback of using chemical fertilizers

Answer 1

They are harmful and if they are taken in by the plants then theie chemicals can enter in our body and can cause dieases.

Answer 2

1st the most drawback is the fertiliser which is used in fields which is only killed insecticides but the small animals such as rabbit, squirrel's eat them an caused to death this is the main reason
2. And the most aggressive use of fertiliser for the protection of crops and urea which is poisoning and mixed with underground water and harmed caused to human being because of impure water because of using of chemical fertiliser.
I hope this helps you