Mark,

I didn't mean to imply you sold any specialty fertilizers, or even that you used them.  My statements were to the effect that those vendors have used the arguments aplenty about 'unlocking' the soil's reserves.

I don't doubt you have improved your soils substantially with no-till, higher residue crops, cover crops, etc.  However, I seriously doubt that significant amounts of P or K became available due to these things.  From everything I've seen, once you average out sampling error, the soil test values over time reflect whether you are net removal (taking more off in grain, etc vs applied) or net build-up (applying more than removal).

Don't get me wrong, biology certainly affects what is plant-available in the soil, but those changes are very slow and relatively minor in the scheme of things. 

Your claims about soil OM climbing from 1 - 1.5% up to 2.5 - 3% in a mere 6 years are amazing.  Again, I strongly suspect sampling error (or using a different lab or method).  Scientists studying switches to no-till and the use of cover crops have trouble measuring changes of that magnitude in that short of a time, regardless of location.  I think the largest values ever validated in the continental U.S. were around +0.1%/yr and many studies fail to detect any changes in OM that are statistically significant at P = 0.05.

Pat,

I don't have any data on changes in nutrient status based on cover crops.  You might be thinking of Juca Sa, Ademir Calegari, or someone along those lines.  The results tend to reflect recycling of nutrients from depth more than alterations in availability of a given volume of soil, from what I understand. 

Jill Clapperton didn't discover mycorrhizae, although she has done considerable work in that area.  Mycorrhizae primarily help in transporting P and certain micros to the plant, rather than altering availability per se (mycorrhizae explore far greater volumes of soil than root hairs, and can function under much drier conditions than the roots themselves).  Again, this is somewhat of a subtle point, since the mycorrhizae are helping plant uptake, but I don't think there's any evidence that mycorrhizae alter the P that is bound to the soil latice.  Perhaps it's best stated that mycorrhizae can help a plant maintain uptake (of P or micros) under lower fertility conditions than the plant could otherwise handle comfortably, but the mycorrhizae won't alter the long-term calculus -- removal must equal replacement, or the soil's productive capacity (and test values) will fall.