ABSTRACT
Farmers worldwide now use 10 times more fertilizer than was used in 1950. Nutrient element depletion of the principal nutrient elements (N, P, and K) ranges from 40 to 60 kg per ha in Latin America and some parts of Africa. World fertilizer use totaled 141 million tons in 2000 (86 million tons of N, 33 million tons of P, and 22 million tons of potash. World fertilizer use between 1950 and 2000 peaked in 1989, decreased steadly from 1989 to 1995, and then began to increase (see Figure 9.1).
