LOL...this is a piddling amt of fertilizer. I suspect the theft is about farming not making bombs. If you’re making a bomb the urea is all thats necessary (aside from some fuel oil) so why steal 3Xs that amt in P and K?
It's more complicated than that. Urea mixed with fuel oil won't explode. You must get almost an equal weight of other chemicals and do a lot of processing first, then use a detonator-booster system.
And even ammonium nitrate-fuel oil takes a considerable amount of booster explosive to go boom. Insensitive explosives are safer and that's why they are used in industry- it's actually very hard to make them “go”.