Prove what? That 1 uro doesn't buy 1 ton of urea. Ok go check out mintpal.
This concept really is hurting your wittle head, isn't it?
The exchange rate between BTC and URO is not what matters here.
What matters, and ALL that matters is if there are suppliers who are willing to sell 1 mt tonne of urea for 1 uro.
If there are, then 1 uro is worth 1 t tonne of urea. The end.
The only question you should be asking is this - Are there suppliers willing to do such a thing?
The coin dev claims yes. Obviously this needs to be proven, since it's the one and only crucial fact in the entire matter.
I believe it's possible there may be such suppliers, as there are certain wider implications and advantages to doing so, as a long term systemic plan. The devs have been smart enough to figure out what those are, even if you're not able to comprehend them yourself.
That doesn't mean I'm sure someone *has* in fact agreed to such a thing, only that I can see why someone might.
What we need is proof that someone really has.
