I have and do raise canola. You do need fertilizer, unless you have seriously overfertilized on the previous crop. Irrigation depends on how far west you are, the 100W longitude is still a good cutoff. You can sorta intercrop by, for example, broadcasting seed into standing crop before harvest, but you have to get it in well before the first frost, so it can grow enough to survive under winter snow. Does not particularly help soil stabilization compared to other winter grasses, roots aint very deep, something like turnips are better. Canola is 40% oil by weight, but you do well to extract about 35% with a press, for more you need to go to something like xylene solvent, which i will not do. The meal can be fed to livestock, but not in excess, they get diarrhea. Canola oil makes pretty biodiesel especially if you use it fresh, but i send it thru the food service industry, collect 85% of it back as used oil for biodiesel.
I looked at miscanthus several times, but the cellulosic ethanol process is still not up to snuff, and i dont want to go through a gasification stage. I'd rather put the land in pasture and run livestock on it.
this is promising, but needs the gasification stage also, before fuel can be made.