02205nas a2200169   4500008004100000020001400041245008000055210006900135260000900204300001100213490000600224520168100230100002501911700002201936700002601958856005101984       2012                        eng d  a1748-932600aEmbodied phosphorus and the global connections of United States agriculture0 aEmbodied phosphorus and the global connections of United States   c2012  a0440240 v73 aAgricultural phosphorus (P) use is intricately linked to food security and water quality.Globalization of agricultural systems and changing diets clearly alter these relationships, yettheir specific influence on non-renewable P reserves is less certain. We assessed P fertilizer usedfor production of food crops, livestock and biofuels in the US agricultural system, explicitlycomparing the domestic P use required for US food consumption to the P use embodied in theproduction of US food imports and exports. By far the largest demand for P fertilizer throughout theUS agricultural system was for feed and livestock production (56% of total P fertilizer use,including that for traded commodities). As little as 8% of the total mineral P inputs to US domesticagriculture in 2007 (1905 Gg P) was consumed in US diets in the same year, while larger fractionsmay have been retained in agricultural soils (28%), associated with different post-harvest losses(40%) or with biofuel refining (10%). One quarter of all P fertilizer used in the US was linked toexport production, primarily crops, driving a large net P flux out of the country (338 Gg P).However, US meat consumption relied considerably on P fertilizer use in other countries to producered meat imports. Changes in domestic farm management and consumer waste could together reduce the Pfertilizer required for US food consumption by half, which is comparable to the P fertilizerreduction attainable by cutting domestic meat consumption (44%). US export-oriented agriculture,domestic post-harvest P losses and global demand for meat may ultimately have an important influenceon the lifespan of US phosphate rock reserves.1 aMacDonald, Graham, K1 aBennett, Elena, M1 aCarpenter, Stephen, R  uhttp://stacks.iop.org/1748-9326/7/i=4/a=044024