Heavy black plastic in full sun over moist soil will kill everything (weeds, worms, fungi, microbes, larvae...) but i don't know how deep the kill zone is.

As cold weather said,you also kill things in the soil that are benificial. I suggest having the soil tested and turning it if it hasn't been recently. Add amendments ( other than N ) according to soil test. Alow weeds to sprout. Shallow till/rake to kill young weeds. Water or rain will sprout new seeds brought to the surface. Repeat the cycle each time weeds sprout. You need only rake/till before plants mature and seed but doing it while they are small is easier and alows more cycles. If you will be home during the fall you might plan a fall garden. If not,plant a winter cover crop which you mow and/or plow under early next year. If the first soil test showed extreme deficence,you might run another test in 2015 so that if needed you can amend before planting. While making a desision,here is something to consider. Most weed seed have coatings of varying thickness and premability which cause them to germinate in multiple years,up to 20 years for dandilions and ohers.

What you are thinking of is solarizing the soil and most everything I have read about this is to use clear plastic, not black, and two layers, not one.
Why do you use "farm soil" with horse manure and not vegetative waste?

Here is a link that might be useful: solarizing soil

I'm with Klem, grow/kill cycles are the way to go for reducing weed seed load in a vegetable garden.

If you can, I would water really well after getting the soil together. When the weeds come up, kill them by tilling, flaming or whatever method you prefer and then plant a thick cover crop to out-compete other weeds and then till that in during the fall or allow it to winter kill and be mulch for next year's crops.

Thanks for the responses. I'll post the outcome later this year!

I'm in the heavy mulch or cover crop circus