If you're really stuck for time or resources for muddying an underground plot, you can farm some crops outdoors on grass or soil instead/as well. You have to gather quite a few plants first, though - Under 'd' for designate, you can select an area outside - it needs to have shrubs in (if you're not sure, just designate a large area, and any shrubs will be highlighted), and one or more dwarves set to gather plants under their labour menu.
Longland grass, strawberries and fisher berries can all be brewed, and probably some others that I forget. The main advantage of above ground farming is that all outdoor crops can be grown in all seasons, and you don't have to fiddle about with water and digging. The downside is you need to gather the plants first (though once you've got a small supply of seeds, brewing them provides more seeds, and your stocks should grow exponentially over time), and your dwarves are more exposed to danger (also, some creatures will steal seeds occasionally).
You basically can't have too much booze. Dwarves get through it a lot faster than any other resource. They like variety too, so grow a few different kinds of crop if you have them.
Pressing 'z' and going to 'kitchen' (you probably need one built, I'm not sure) will show you what seeds can be brewed or cooked. The others can mostly be used to make dye or fibre for cloth, but they're not very important.