  Starting with an entropy that includes volumetric, area and length terms as
well as logarithmic contributions, we derive the corresponding modified
Newtonian gravity and derive the expression for planetary orbits. We calculate
the shift of the perihelion of Mercury to find bounds to the parameters
associated to the modified Newtonian gravity. We compare the parameter
associated to the volumetric contribution in the entropy-area relationship with
the value derived for galactic rotation curves and the value obtained from the
cosmological constant.
