There may be some difference between a fast windbreak and an ideal windbreak.
Since many fast growing deciduous trees provide little wind breakage in the winter months, my go-to choice for screening/windbreaks is Thuja (standishii x plicata) 'Green Giant' .
I am in USDA
hardiness zone 6 and they thrive here in Pennsylvania.
Here are some reasons why I prefer this tree over some others (such as leyland cypress).
The plant can easily put on 3 feet a year or more Adaptable to all soil types (sand, clay, shale, low nitrogen, dry, etc) except for saturated.
Very uniform grower in a group planting such as a windbreak Flexible branches can easily withstand 2' of snow
Bright green year round Deer resistant (as compared with emerald arborvitae)
Very disease/pest resistant - generally carefree Thrives in dappled to full sunlight
The downside is the cost, which is high if you are getting large trees to start with, like most people prefer to do.
But if you start with 3' trees, you have a 20' windbreak in less than 10 years, and 30' ten years after (with proper spacing).
That is fast for a conifer.
If you need a deciduous tree for some reason, i would choose the 'Hybrid Willow' , for fast growth.
They advertise 12-20' of growth a year, but when I've planted them, they pushed 6-10' a year for the first few years.
Still pretty fast though.
Because this isn't a long lived tree, and won't look so great after 30 years, I'd plant a second row of trees (something slower and more substantial) in the back.
When they reach the height you need, you could cut back the willows (In that case prepare for insane regrowth).
Here's a list of good windbreaks that take longer to grow (only species which I've used for this in zone 6 where I live): Blue Spruce , Very dense, generally carefree, not uniform if grown from seed Eastern White Pine , faster growing, less dense.
Can be picky with soil Dawn Redwood , good apical dominance, grows in damp or dry soils.
Less dense, deciduous.
Fast growing Bald Cypress , similar to Dawn Redwood, slower growing, can grow in wet soil/standing water Norway Spruce , one of the best adapted conifers to this climate.
Dense with sufficient moisture (dry soil causes shedding of branchlets)' Street Keeper® Honeylocust .
Very happy with the growth rate, density, structural integrity and pest/disease resistant.
Adaptable with an aggressive root system.
And some which I did not prefer (ended up being high maintenance or needing replacement with a different species) Lombardy Poplar , short lived, disease prone, prone to storm damage (also cottonwood) Douglas Fir , not well adapted to this climate.
Needs yearly spraying for needle cast and other diseases Siberian Elm , not very dense, prone to storm damage Black Locust , low foliage, disease prone
gardening.stackexchange.com/users/419/J. Musser
Depends what you want in the way of thickness of foliage blocking the wind or whether the barrier should be effective against other things such as deer.
I have light sandy type soil and wanted to plant white pine as a windbreak and later for lumber.
But the deer ate all the seedlings except one.
Then I planted white spruce which the deer left alone; they produced a nice thick barrier which is very good against wind and somewhat effective against deer.
An alternative that gorws fast, makes a less thick barrier but is vulnerable to beaver damage here is white poplar.
(Zone 3)
gardening.stackexchange.com/users/15063/Colin Beckingham
My favorite is Blue Arctic Willow, Salix purpurea 'nana'.
Not 'nana' at all.
Full of foliage, flexible fine branches, grows quickly...looks spectacular summer and winter (glossy copper fine branches that don't break).
Easy and fun to prune, heck, I made hedges out of them...
if one doesn't hedge, they grow to 30 feet by 30 feet.
Blue green foliage, tiny leaves, forget about cleaning leaves off lawns, etc.
Terribly hardy down to zone 1B!!
Not enough woody trunk or stems for beaver to care about.
They might want to use stems for weaving...
dunno.
Deer?
Dunno, lots of branches and foliage
but I've never seen any deer damage.
That copper shines in the winter.
So easy and actually fun to prune.
Moves in the wind.
Check out this wonderful shrub!!
I can send pics if you'd like!
gardening.stackexchange.com/users/3351/stormy
I can recommend Colorado Spruce - Picea pungens.
It is grown in our gardens as an ornamental tree in 99% of cases.
However, it is less known that it is one of the best windbreak trees ever.
It will calm down the strongest winds, almost unbelievable effect.
Plus, there are numerous cultivars for every taste.
It does grow a bit slower than average, but if you are patient, give her a chance!
gardening.stackexchange.com/users/19946/VividD
It would be very helpful to know several more factors about Alina's field site. "
USDA Zone 6" refers only to average minimum and maximum temperatures.
I didn't see any mention of state and region--but I am very new to this blog.
The woody plants that contributors have mentioned will not grow equally in all climates and soils in Zone 6.
We readers need to know: Amount of precipitation, by season.
The West, for instance, has very little rainfall in summer, which often severely limits which species will thrive.
The very fertile Palouse region (Zone 6) of northwestern Idaho and neighboring parts of Washington have historically used Black Locust on ridgetops.
This has been successful, though this species is now succumbing to an exotic borer insect.
Colorado Spruce, as VividD noted, is dense--and it is also somewhat drought-tolerant as well as disease and pest resistant in the West.
If the windbreak will be on a ridge.
If so, adequate moisture becomes even more essential.
Will the windbreak be some distance from the field?
If not, rhizomatous trees (e.g. certain poplars) may invade the field, sometimes during a single fallow season.
However, with luck, the rhizomatous feature could serve to increase the density of the windbreak.
gardening.stackexchange.com/users/24506/Sonja Lewis
I'm searching for species that would grow fast to become field windbreaks and I have found a lot of articles on the web about this.  However, I'm more interested in knowing if any of you have had or have actually grown them (in USDA hardiness zone 6). What species would you recommend based on such expertise?
What are the best fast growing field windbreaks?
gardening.stackexchange.com
<trees><shrubs><field-windbreak>
gardening.stackexchange.com/questions/30796
gardening.stackexchange.com/users/16253/Alina
A hybrid willow is a fast growing, deciduous tree. For Evergreen, try Thuja, Bald Cypress, Norway spruce, white spruce or Colorado spruce. A fast windbreak is not necessarily an ideal windbreak as many fast growing deciduous trees provide little wind breakage in the winter  months. The  'Hybrid Willow' is a good decidous tree for fast growth. Other suitable options areThuja, bald Cypress , Norway Spruce , Honeylocust, blue arctic willow, Colorado spruce, white poplar and white spruce, which is very good against wind and somewhat effective against deer.  
A fast windbreak is not necessarily an ideal windbreak as many fast growing deciduous trees provide little wind breakage in the winter  months.  The  'Hybrid Willow' is a good decidous tree for fast growth. Other suitable options areThuja, bald Cypress , Norway Spruce , Honeylocust, blue arctic willow, Colorado spruce, white poplar and white spruce, which is very good against wind and somewhat effective against deer.  