Why is fertilizer essential

Fertilizer is essential in agricultural practice because it adds the needed nutrients to the soil.

Explanation:

Given that each successful cultivation of crops leads to the removal of nutrients in the soil. To retain the level of nutrients in the soil so the plants can germinate extremely well. There is a need to add fertilizers to the soil.

Therefore, fertilizers are essential because "it adds the needed nutrients to the soil." Thereby retaining and improving the harvest level of plant crops.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.