N-P-K fertilizer application rates by crop and country for circa 2020

All fertilizer application rates are on elemental basis (P = P2O5 x 0.436;
K = K2O x 0.830). Imputation to build complete crop x year N-P-K time
series data: Subnational- to global-scale understanding is built
using FUBC information collected from individual countries and
sub-nationally with ~800,000 data points for 1980-2022. Briefly, a
three-step imputation process with an additional preprocessing was used.
In the first step long-term average FUBC was determined. In the second
step the exact year observations was identified, which is then allowed to
pass on unchanged. In a final third step the numbers from the first and
second step are readjusted (observations are not adjusted) to flexibly
match the total agricultural fertilizer consumption in a country as
reported by the FAO. Sub-national FUBC rates for ten major crops in 25
agriculturally important countries use a similar three-step iteration
method. For the remaining countries, only the national FUBC values are
reported. For mapping the fertilizer application rates of the ten major
crops an annual gridded crop dataset was used.