Distant Views and Local Realities: The Limits of Global Assessments to Restore the Fragmented Phosphorus Cycle

Abstract

O ver the last 60 yr, global extraction of phosphate rock for fertil-izers has tripled to increase agricultural productivity and sustain a growing global population (MacDonald et al., 2012). The use of phosphorus (P) fertilizers has opened up vast tracts of otherwise unproduc-tive farmland, which has improved food security and promoted economies of scale in agriculture, food production, and trade. Even so, there are legiti-mate and increasing concerns about the global efficiencies and sustainabil-ity of society's current use of P, with only a small proportion (<20%) of P mined for fertilizer reaching the food that is consumed (Neset and Cordell, 2012). Large-scale P losses from agriculture and urban areas impair water quality, with profound and widespread detrimental impacts on water secu-rity, ecosystem sustainability, and human health (Jarvie et al., 2015). As nutrient enrichment and related impairment of surface waters continue to expand, many sectors of agriculture have faced increasingly intense scrutiny and, in some cases, litigation (McBride, 2011; Iowa Drainage District Association, 2015; Sharpley et al., 2012). The ensuing implementation of nutrient management strategies and conservation measures is bringing improvements in water quality, albeit more slowly than expected or desired by end-users of those water resources (Sharpley et al., 2013). Running parallel with water-quality concerns related to P management in different sectors of agricultural production is the growing recognition that not only are supplies of mineral rock P finite, but there is an absence of a coordinated strategy for P conservation and recovery (Scholz et al., 2015). This abundance–scarcity paradox has stimulated assessments of global flows, stocks, and stores of P, using a plethora of regional and global datasets. With greater access to more sophisticated data compilation, storage, computing power, and analytical capacity, the evolution and use of meta-analysis have expanded rapidly. Indeed, greater availability of data has created opportunities for different agendas and narratives to be elevated above the level of local, agricultural production concerns, expanding the scope of perspective. However, the disparities in scale between global assessment of P cycling and local social, environmental, and economic factors, determining farm management, can mean that recommendations Abstract: With more sophisticated data compilation and analytical capabilities, the evolution of " big data " analysis has occurred rapidly. We examine the meta-analysis of " big data " representing phosphorus (P) flows and stocks in global agriculture and address the need to consider local nuances of farm operations to avoid erroneous or misleading recommendations. Of concern is the disconnect between macro-needs for better P resource management at regional and national scales versus local realities of P management at farm scales. Both agricultural and environmental researchers should focus on providing solutions to disconnects identified by meta-analyses and ensure that production and conservation strategies consider farming realities.