I think my options are scythed hayfield, grazing area for animals, wildflower area for bees (honey harvesting), but I really like the idea of a lavender field (maybe I could sell at a farmer's market). It's near the house so there is an aesthetic issue to consider. It would look really nice if I can make it look like the pictures on the internet - but I'm not sure how much work this is... I do have the right Mediterranean climate and poor soil for Lavender.
These are a couple ideas I could think of for a leech field:
-growing your own clothing fiber (cotton, flax, nettles)
-plants for dyes (madder, woad, weld, indigo, pokeweed, hibiscus, etc)
-plants for candles/tea/aromatherapy (mint, lavender, basil, thyme, oregano, jasmine)