In 2007 I grew about 900 acres of alfalfa and only one 58 acre field of corn.  This year I only have the 58 acre field in alfalfa and the rest in corn.  This 58 acre field had 30t/a of feedlot manure applied before the corn in '07, and planted back to alfalfa in 2008.  This is it's 4th year in production and has never had any commercial fertilizer spread. 
1st cutting made 4.08 tons/acre
2nd cutting made 2.92 tons/acre
3rd cutting is makeing 1.86 tons**/acre so far I've only baled the endrows and some small squares, and will finish baling in big squares if the humidity ever goes down.
4th cutting ???  I'll cut in mid-September but my best guess would be 1.25 t/a
So about 10 ton of dry hay for the year. Last year was closer to 9, but test was better.
I do not irrigate it, or spray it.

This is why it produces:
1.  It has good soil with adequate nutrients.
2.  The ground has had manure in the past (just the once)
3.  It has good drainage, but slopes little enough that rain has a chance to soak in.
4.  It has sub-irrigation groundwater it can tap into 10 feet deep or so.
5.  It is planted to Dairyland Hybriforce 400
6.  It was planted thick with 24lbs of seed/acre. (plant thick to make plants compete against each other)
7.  I limit compaction and traffic.  This is a nearly free way to increase yield.  I use a bale accumulator and only drop bales on the 2 field ends (ecept the few small squares I made this weekend)        I would guess that 80% of the field has never been driven on since it was planted.  I allways start cutting at the same side and tracks usually follow the same lines.  Wheel tracks go the same way the water runs so they don't puddle up with rain.
8.  It has been one of the first fields cut each cutting and it has better odds of getting put up without rain, less chance of trampling regrowth. 
9.  Bales are picked up right away so re-growth is not damaged by equipment clearing hay, and even if there is some regrowth when clearing bales, only the endrows see any traffic from the clearing operation.   Rained on hay also kills yield                                                                              
10. It wasn't cut until 10% bloom this year on 1st,2nd,and 3rd cuttings because of weather and markets.  And alfalfa cut with a little bloom yields the most (as long as you aren't clipping off the new shoots) and in a year with a severe drought it can be the most profitable. 

If dairy hay/milk prices are high, dry cow hay is abundant or low priced, and weather permits, I cut at pre-bloom for dairy hay and can usually get 5 cuts, but 20% less tonnage over the course season.

It will be the most profitable field on my farm this year even with $7 corn.  But it is also the most brute work and worst schedule and I just don't like putting up hay anymore- haying is a young man's game so have at 'em!  (some might say I'm young but I feel old :>)


Here's a picture of raking the last pass 1st cut this year.

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Springthroughjuly252011 440.jpg (37KB - 1080 downloads)

Springthroughjuly252011 432.jpg (49KB - 1115 downloads)