Does dog poop fertilize the land?
Fresh dog poop is an environmental hazard in that it may contain a variety of pathogens that can affect other dogs and humans. Thus dog owners should not leave dog poop in public places but should collect it up and dispose of it safely.
However, once decomposed dog poop (along with all animal poop) will release nutrients back into the environment that will benefit plants. So yes, dog poop will fertilize the land.