I recently read an article about the likelihood of declining phosphorus production. Have you seen it? If not, it's well worth the time, & I strongly recommend giving it a look at www.dailyyonder.com/forget-oil-worry-about-phosphorus/2010/09/08/2929.
Is this a concern for farmers? It could be, although there are many areas with naturally high P levels or have a readily available supply through animal manures. Economic factors may change the value that manure is given today & could well make it more valuable in the future, even with additional transportation costs.
What do you think? Is this a big deal or not?