How to start a virgin field

So I've got a beautiful few acres of virgin farmland I'm wanting to work, but for some reason, it's covered in grass instead of mulch and cardboard.  I know that would be the gradual way to get things going, yet part of me wants to give into the temptation of just tilling it and planting heavily with alfalfa and other cover crops.  Does that make sense in this context?  I know it's not recommended as a regular practice, but to get things going, what do you think?

Greetings,
   
I suggest; be more planful.
Start with a soil test.
Plan a food forest.
If its truly virgin land tilling it would be destructive.

Start gradually!

I would try to get a few of the larger trees that you might want started. 

Then start a small area for cultivation and each year bring more of the whole towards your aimed for Eden! 

  Swales are only nesisary if you have run off if so make swales first.
To get my forest gardens going I tilled and planted perennial runner beans with corn. 
After two months (due to further cultivation) I start introducing other species. Using this method I have been turning a profit during the first year of establishment. I later plant some other main crops and begin to diversify more as time goes on. This fall I will be planting chaiyote squash, pecan, walnut, rye grass and hairy vetch. After febuary I may also plant lupinus mutabilis, broad beans, swiss chard, epazote, manzania, and chenapodium guasuntle (Mexican quinoa).
  If you have lots of money I would suggest you mulch the whole thing and buy trees exc. but if your broke and you need to turn a profit this year I suggest a semi annual, biennial or even annual crop that you can plant into as you go.

I know there is opposition to tilling but if you only do it once what's the big deal. Some permaculturalists may not like my "gett'er done" attitude but I have 6.5 hectars or like 15 acers of food forest and apart from the land cost I've put in less than $2000 US.

Thanks man, I appreciate the input.  I have a similar feeling, if it's only cultivating once to get things started, isn't that a good use of resources, and can't the land deal with it?  As for the best way to cultivate, I've heard some people mention plowing then disking being less hard on the soil, which makes sense to me (less mixing soil with subsoil.)  I think I'll probably do a variety of things to see how it works differently-- plain mulch some, mouldboard plow then disc some, chisel plow some in a checker board fashion and then remove the chunks of turf by hand and probably mould board plwoing on counter multiple times to make some swales.  How will I know what works better unless I try?  If anyone has any other suggestions for methods, I'm all ears. 

P.S.  It's not actually a virgin field, just fallow for decades.  So it's not complete pristeneness I'm tampering with, if that makes anyone feel any better. 

You might want to look into Keyline Plowing.

http://www.keyline.com.au/ad1ans.htm

Find your contours first . This will make it easier to start .
Define the area for a house and zone 2.
Draw up a rough plan with the contours and set out the bigger trees locations in zone 3.
Keep in mind if you want pastures for chickens or other animals.
Put the big trees in first. The plan can grow around this and then you can
decide how to work the areas in between.
If the land has been ploughed in the past (fallow for decades) dig a deep hole
to understand if a hardpan has developed from previous ploughing.
personally I would only plough with a chisel on contours.