This note describes the methodology behind the computation of the fertilizer/crop price ratio discussed in the Fertilizer Section of the AMIS Market Monitor reports. The indicator gauges the affordability of fertilizers compared to crop prices, and reflects the relative evolution of fertilizer prices compared to crop prices since January 2020, indexed to the 2019 annual average. For each combination of country and crop, the price of a relevant fertilizer is compared to the price of the corresponding AMIS commodity.