In frogs, different mating seasons are a (n) to reproduction

In frogs, different mating seasons are a barrier to reproduction.

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.