I've done straw bale gardening. It depends somewhat on how high the straw really is as sometimes people don't really have a bale thickness but what I've tended to do is to part the straw a little, put a small pot full of earth there into a mound and plant into that. Say good, healthy seedlings that you know will throw roots quickly. It can be reasonable to part the straw completely and plant IF the soil is rich and healthy and suited for the plant BUT wet straw around a plant can lead to stem rot etc so best not to have the straw right up against the plant at all.
What sort of plants are you wanting to put in? Vegetables or flowers or flowering shrubs or..? And are you planting seedlings or more mature plants..?
It would be perhaps easier to simply do a google search on 'straw bale gardening' and look at info sites. I'm not sure about corn but again it may be the issue to do with rot and mould. If straw is soaked and stays that way for a long time it was get blackish and mouldy. You need to water well but it's best to not let the straw stay soaked for days in possible. Obviously you can't help if bad weather hits.