With all that phosphate you may have invested for more than one generation of hay growers.
actual applied was:
N: 21 lbs/ac
P: 100 lbs/ac

 

I may have been closer to the mark than some might think.  The year of application 20% of the applied is available that year, the remainder is tied up.  Each succeeding year up to 20% of the residual is available to the crop. String 20% of the remainder out and that will be close to 10 years.

True I was basing my smart comment on the speculated amounts posted by others also.

In the 1950 the Government would pay 66% of the fertilizer cost if it was 0-21-0 phosphate up to 300 lbs worth. That was 60 lbs of Phosphate and our 2.5 T/A used 30 lbs of phosphate.  { 2.5 X .25% = 5 lbs P = 12 lbs P2O5. After 6 or 8 years the Gov decided they would only subsidize 200 lbs of fertilizer but we could use 0-45-0 if 90 lbs of phosphate and we were only then venturing into 3 T/A/yr. I figured that even though I was applying 10-34-0 fertilizer or 0-45-0 I was still utilizing some of that phosphate my father put out.

 

Oklahoma tells us we can apply 6 years worth of phosphate (600 lbs phosphate) before planting and realize more total yield over the life of the stand than with semi annual or annual applications. 

Perdue tells us that  applications of excessive amounts of phosphate is counter productive, unless we also apply a good amount of potassium.  Say at least half the expected yield for that stand. Say enough for half of your probable 15 tons/A? or at least 450 lbs of K2O /A. I have found that 500 lbs to 600  lbs of Murate of Potash plus an equal amount of K-Mag will do more for alfalfa yield than 1,000 lbs of MOP.

 

Now organic crops is basically what we had in the 1950's. I put the pencil to the problem and determined I could grow Organic Alfalfa and sell it for not much more than I ask for my alfalfa now.  

We are not too far from Austin Texas a hot bed of organic types with milk goats. My favorite market is the goat dairies.

 

Could except for their idea that most Murate of Potash is not Kosher.  That K-Mag here is not Kosher.  That to be organic I would have to have a buffer strip between the organic crops and the conventional crops. Their wording was such that I would loose 20% of my productive alfalfa ground. Then I would have to pay some inspector to drive up from Houston to grade my operation. Flat fee plus miles plus food, plus hotel. 

Then I listen to the pressures applied to the numerous dairies who have similar inspectors.  There is a tremendous opportunity to collect a little graft for a unscrupulous inspector. That last part was the deal breaker.  If they want I can supply All Natural Alfalfa at market prices, but not Certified Organic.

 

A little side deal, the only phosphate allowed, except for animal waste, is rock phosphate. Rock Phosphate is just another rock in a soil with an 8 pH and 10% free lime. 

Now I have heard that some use rock phosphate in a trench PLUS enough elemental Sulfur to convert Rock Phosphate to P2O4. Now where does that elemental sulfur come from, Makes no matter as long as the paper work looks good. They are making a home brew 0-21-0 fertilizer!

 

Organic works as long as there is a closed shop. Limit the supply and encourage the demand and charge what you wish.  Take a look at California!  There the heavy hitters have stepped in and now the wife can buy California Organic from Wally World for about the same price as the other offerings. They are putting the Mom & Pop little operations out of business, just like Walmart.

It should be no problem for some of the heavy hitters in the hay business to comply with all the Organic Rules, and have a stick stout enough to keep the inspectors honest.  That happens and Certified Organic alfalfa will could be shipped on from the Dakota's from farmer with 3,000 acres of irrigated alfalfa.