For a reader what to two or more things, the reader must consider how the things are different.​

It is an obvious thing when you are going to contrast or compare two things, you must see the things one by one to find the difference between them, this is the important to read or study about the things individually to find the difference. when you know about them, you can compare easily.

Explanation:

crop rotation kepy different plants in the soil instead of once constintly. when switching out plants you have different nutrients being absorbed at different speeds and different roots growing differently therfore the spoil and water flow have to adapt and carry fresh nutrients to carry the constant changes that were going on in the soil.