If you keep the top of the soil in seedlings constantly wet, you're likely to get dampening off, the common name for one of a number of fungi that thrive in moist conditions and kill your seedlings. Make sure you've got good air circulation and bottom water your seedlings allowing the top surface to remain dry. We're seeing little dampening off this year but I took a photo of the one plant I found with this ailment.
ALM & Full Circle Seeds Farm Blog
ALM & Full Circle Seeds Farm Blog. Information about how to grow food & seed organically