Depth of field and focusing distance

The shorter the focal length of your lens the more depth of field you get for any set aperture.
For a set focal length and aperture the depth of field shrinks as the focal distance is reduced.
so:-
a 35mm lens set at f5.6 will give more depth of field than a 90mm lens set at the same aperture at the same distance.
and
a 90mm lens set at f16 at a distance of 15m away from the subject will give you more depth of field than if you were focused at 5m away from your subject.