After 1950, in response to record growth in worldwide food demand, farmers worldwide sharply increased fertilizer use  As a result, the productivity of farmland more than doubled by 1985  Since 1985, farmers have sought to increase farmland productivity even further
Nevertheless, worldwide fertilizer use has declined by 6 percent between 1985 and the present
Between 1975 and 1980 fertilizer prices temporarily increased because of labor disputes in several fertilizer-exporting nations, and these disputes disrupted worldwide fertilizer production.