Generally speaking, if the same crop is sown in a field for several successive years, growth in the later years is po...

Ravi October 1, 2020

@mak16153, (A) is incorrect because while this choice could explain why some plants grow faster than others, it cannot explain why a single plant type would grow more poorly after many years in the same soil. Also, we can't assume that alfalfa is one of the "some kinds of plants" that this choice mentions, so we can get rid of it.

mak16153 October 5, 2020

That what's I thought. Makes senses. Thank you!