I tilled up about 1/4 acre for the 2011 garden. This should be enough to raise all of the vegetables the two of us can eat and leave lots to share. I have been over the soil at least 10 times with my Troybilt horse tiller. There are lots of canary grass rhizomes in the soil. I expect that if i can till it several times through the winter and several more times next spring I can disturb those rhizomes enough to eradicate the canary grass.
I also spread and tilled in 30 cubic yards of Cedar Grove compost. That is equivalent to about 1 1/2 inches over the whole garden. My purpose is to increase the organic content of the soil so that it will hold moisture better next summer. If I also mulch it with this years cut hay and use drip irrigation I can minimize the need for water next summer. Since all we have for water is a 40 foot deep hand dug well, we need all the water conservation we can get.