[en] We work out details of a previously proposed scenario for baryogenesis in a superstring model, based on the Affleck-Dine mechanism exploiting the decays of large expectation values for squark and slepton fields after inflation. We show how the coefficients of the relevant quartic scalar operators can acquire the necessary imaginary parts. We examine possible sources of entropy among the gauge-singlet scalar and fermion fields including the gravitino, as well as the low-energy SU(2)_L . U(1)² → SU(2)_L . U(1)_Υ → U(1)_em phase transitions. We argue that none of these dilute substantially the baryon-to-entropy ratio, which can easily be in the range preferred by cosmology. This means, in particular, that the Polonyi and gravitino problems are solved. (orig.)