  Environmental effects such as ram-pressure stripping (RPS) shape the
evolution of galaxies in dense regions. We use the nearby Virgo cluster as a
laboratory to study environmental effects on the non-thermal components of
star-forming galaxies. We constructed a sample of 17 RPS galaxies in the Virgo
cluster and a statistical control sample of 119 nearby galaxies from the
Herschel Reference Survey. All objects in these samples are detected in LOFAR
144 MHz observations and come with H$\alpha$ and/or far-UV star formation rate
(SFR) estimates. We derived the radio-SFR relations, confirming a clearly
super-linear slope of $\approx1.4$. We found that Virgo cluster RPS galaxies
have radio luminosities that are a factor of 2-3 larger than galaxies in our
control sample. We also investigated the total mass-spectral index relation,
where we found a relation for the Virgo cluster RPS galaxies that is shifted to
steeper spectral index values by $0.17\pm0.06$. Analyzing the spatially
resolved ratio between the observed and the expected radio emission based on
the hybrid near-UV + 100$\,\mu$m SFR surface density, we generally observe
excess radio emission all across the disk with the exception of a few
leading-edge radio-deficient regions. The radio excess and the spectral
steepening for the RPS sample could be explained by an increased magnetic field
strength if the disk-wide radio enhancement is due to projection effects. For
the galaxies that show the strongest radio excesses (NGC 4330, NGC 4396, NGC
4522), a rapid decline of the SFR ($t_\mathrm{quench} \leq 100$ Myr) could be
an alternative explanation. We disfavor shock acceleration of electrons as
cause for the radio excess since it cannot easily explain the spectral
steepening and radio morphology.
