Iowa fertilizer prices are down significantly from 2012, however fertilizer prices have been on the rise since late 2017. In 2012, urea prices were near $800/ton, but have since declined to $366/ton as of November 2018. Liquid nitrogen 32% has averaged about $344/ton from 2012-2018, but is currently $258/ton. Liquid nitrogen 28% is $200/ton as of November 2018, significantly lower than the average of $318/ton from 2012-2018 and is also lower than the 12-month average ($227/ton).
Anhydrous ammonia prices increased from an average of $375/ton in November of 2017 to averaging $480/ton in November of 2018. When looking at the Price/lb Nitrogen graph, you can see that anhydrous ammonia remains the cheapest price per pound of nitrogen.
Potash (red) is currently at $364/ton as of November 2018 which is slightly higher than the 12-month average ($350/ton). DAP is currently at $505/ton and MAP is at $527/ton as of November 2018.
Propane (LP gas) is currently at $1.24/gallon and average farm diesel fuel prices have been on the rise and are currently $2.63/gallon.