  The Affleck-Dine mechanism, which is one of the most attractive candidates
for the baryogenesis in supersymmetric theories, often predicts the existence
of baryonic Q balls in the early universe. In this scenario, there is a
possibility to explain the observed baryon-to-dark matter ratio because Q balls
decay into supersymmetric particles as well as into quarks. If the gravitino
mass is small compared to the typical interaction energy, the longitudinal
component of the gravitino behaves like the massless goldstino. We numerically
calculate the goldstino production rates from Q balls in the leading
semi-classical approximation without using large radius limit or effective
coupling. We also calculate the quark production rates from Q balls in the
Yukawa theory with a massive fermion. In deriving the decay rate we also take
into account the scalar field configuration of the Q ball. These results are
applied to a realistic model in the gauge-mediated supersymmetry breaking and
yield the branching ratio of the Q ball decay into the gravitino. We obtain the
branching ratio much smaller than the one estimated in the previous analysis.
