Farmers rely on phosphorus fertilizers to enrich the soil and ensure bountiful harvests, but the world’s recoverable reserves of phosphate rocks, from which such fertilizers are produced, are finite and unevenly distributed. Stevens Institute of Technology is spearheading an international effort to map the global flow of phosphorus, much of which will be absorbed by crops, then eaten and excreted as waste by animals and people—and jump-start efforts to recapture and recycle the vital nutrient.