Global views should reflect local realities
Greater access to more sophisticated data compilation and analytical capacity has allowed meta-analysis of nutrient cycling and sustainability at global scales. This is the case for phosphorus (P), given that sources are finite, yet freshwater impairment by excess P remains a ubiquitous paradox. A recent commentary in Agricultural & Environmental Letters examines the use of “big data” in meta-analyses of global P cycles. The authors acknowledge that these meta-analyses can provide valuable insight and identify disconnects, but they are often better at identifying problems than developing solutions.
Global analyses of P can fail to account for local social, economic, and environmental constraints farmers face daily and lead to misleading or erroneous conclusions. For example, an analysis of P cycling in grasslands concluded that P fertilization must increase fourfold to offset soil fertility declines from anticipated growth in livestock production. Such conclusions should consider the increased risk of P loss in runoff with increased P fertilization and the likelihood that animal feeding operations sustained by the world’s croplands would also bolster livestock production.
As an agricultural and environmental research community, we must work together, along with farmers, to ensure management and conservation strategies acknowledge the realities of farm operations, which drive farmer behavior, and which are critical to enacting fundamental, positive change in land and water management.