24th Pacific Science Congress (PSC-24)

Disparities between soil-P inputs (fertilizer, manure) and outputs (crop uptake) cause phosphorus(P) soil imbalances in the form of P surpluses or deficits, posing environmental and food security challenges. With increasing globalization, international trade may accelerate soil-P surplus or deficit, however its influence on soil-P imbalances is largely unknown. Here, we integrate detailed spatial and sectoral information on soil-P balances into a global trade model to capture global footprints of soil-P surplus and deficit across 90 countries and regions. We find that, from 1970 to 2017, soil-P deficit – largely ignored in previous footprint studies – has more than doubled, far exceeding the 24% growth rate of soil-P surplus. International trade of goods and services contributes about 26%-31% of global soil-P surplus and deficit. Low-income food-deficit countries export five times as much soil-P deficit from cropland as they import, highlighting the food security risks related to P-deficit implicated in trade in these vulnerable regions.

soil-P imbalance; multi-region input-output analysis; consumption-based accounting; phosphorous