Crop rotation improves the quality of soil because: Select one:
Soil is not loosened so less erosion takes place
Weeds and vegetation are allowed to grow
It prevents pesticides from affecting crops
Humans mess with natural processes
Different plants require different nutrients

2nd one

Explanation:

crop rotations with nitrogen fixing crops such as legumes and some cover crops, can help put nitrogen back into your soil naturally. this makes soil healthy and can increase yields

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.