Go to a local furniture or appliance store and get some large sheets of cardboard from the boxes the appliances come in - they fill dumpsters with it on a weekly basis.
Put down at least couple of layers of cardboard - it'll smother any grass and weeds underneath, and will take it most of a year to decompose - and you can usually find plenty of earthworms underneath, if you need some for fishbait.
May not be real pretty, but there's no adverse environmental effect.

if you mulch over the cardboard, its not quite so ugly...

but I have to agree, a few layers of cardboard is everything that 'landscape fabric' isn't- low impact, safe, biodegradable...and effective without ruining the ground for worms and things that belong there ;)