title: Improved phosphorus use efficiency in agriculture: a key requirement for its sustainable use.
abstract: Mineral phosphorus (P) fertilizers processed from fossil reserves have enhanced food production over the past 50 years and, hence, the welfare of billions of people. Fertilizer P has, however, not only been used to lift the fertility level of formerly poor soils, but also allowed people to neglect the reuse of P that humans ingest in the form of food and excrete again as faeces and urine and also in other organic wastes. Consequently, P mainly moves in a linear direction from mines to distant locations for crop production, processing and consumption, where a large fraction eventually may become either agronomically inactive due to over-application, unsuitable for recycling due to fixation, contamination or dilution, and harmful as a polluting agent of surface water. This type of P use is not sustainable because fossil phosphate rock reserves are finite. Once the high quality phosphate rock reserves become depleted, too little P will be available for the soils of food-producing regions that still require P supplements to facilitate efficient utilization of resources other than P, including other nutrients. The paper shows that the amounts of P applied in agriculture could be considerably smaller by optimizing land use, improvement of fertilizer recommendations and application techniques, modified livestock diets, and adjustment of livestock densities to available land. Such a concerted set of measures is expected to reduce the use of P in agriculture whilst maintaining crop yields and minimizing the environmental impact of P losses. The paper also argues that compensation of the P exported from farms should eventually be fully based on P recovered from 'wastes', the recycling of which should be stimulated by policy measures.
authors.affiliation: Agrosystems Department, Plant Research International, Wageningen University and Research Centre, PO Box 616, 6700 AP Wageningen, The Netherlands. jaap.schroder@wur.nl
authors.forename: J J
authors.initials: JJ
authors.lastname: Schröder
authors.forename: A L
authors.initials: AL
authors.lastname: Smit
authors.forename: D
authors.initials: D
authors.lastname: Cordell
authors.forename: A
authors.initials: A
authors.lastname: Rosemarin
mesh_terms: D000383:Agriculture / Q000379:methods* / Q000706:statistics & numerical data; D003247:Conservation of Natural Resources / Q000379:methods*; D005308:Fertilizers / Q000706:statistics & numerical data; D010758:Phosphorus
chemical_list: D005308:Fertilizers; D010758:Phosphorus