World Phosphorus Use Efficiency for Cereal Crops.

Recent estimates of world phosphorus use efficiency are not available. The objective of this paper was to estimate P use efficiency for cereal crops on a global scale. Phosphorus use efficiency (PUE) was determined using world cereal harvested area, production, and P fertilizer consumption from 1961 to 2010 in addition to assumptions established in previous research. World PUE of cereal crops was calculated as the amount of cereal grain P removed minus P in the grain coming from soil and divided by the amount of P fertilizer applied to cereal crops. Results showed that area under cereal production accounted for 47.9% to 61.3% of the total agricultural land. Cereal grain yields increased from 1.35 Mg ha^-1 to 3.57 Mg ha^-1 between 1961 and 2010. In 1961, the world’s fertilizer P consumption was 4,765,810 Mg and has increased to 16,523,480 Mg of P fertilizer today. This represents a 346% increase in P fertilizer usage in 50 years. This study demonstrated that world PUE of cereal crops are generally low and indicated that there is a considerable opportunity to promote improvements in the use of P fertilizers. Global PUE for cereal crops ranged from 12.0% in 1980 to 20.2% in 2008 while estimated mean world PUE for 50-years (1961-2010) was 15.7%.