We delivered fertilizer to our customers in rural Kenya. We rented 10 ton lorries, hired trucks, and set up distribution points around rural schools and churches. For two weeks, we literally schlepped tons of fertilizer.
Fortunately for us, it was DAP (planting fertilizer) and CAN (topdress fertilizer). The nice thing about Kenyan agriculture is that most farmers, if they have a cow, already are making sure to use their manure. The bad news is there's not nearly enough cows making nearly enough poop in Kenya to provide the nitrogen the crops need. We're literally shit out of luck... :)
We built a network of agrodealers that we use to check people out. It's scaling pretty effectively now.