The manuring isn't the problem, it's what the soil was recently. Wire worm occur most frequently on grassland or pasture which has recently been dug over or ploughed up.

Thanks Bertiefox. The soil is good, the muck is still quite fresh so I will dig it deep and hope for a good crop. Im at the beach so hope the well drained soil will let any nasties get away.

If the muck is very fresh, the only problem is that it might cause nitrogen depletion in the soil if it has not fully rotted. So that might affect the overall weight of the crop.
If you haven't already dug it in, why not just use the compost on the surface around the growing plants to help 'earth them up'. The worms will do the rest. Most plants benefit from surface feeding which is where most of the feeding roots are. Although I take your point about anything to keep in moisture in your well drained soil. Have you tried surface mulches to do this?