Uh, what is peecycling? It might sound weird, but people have been nourishing crops with human urine for centuries. Why? We ingest nutrients like nitrogen, phosphorus, and potassium, then excrete them. Plants need them. Fabien Esculier — a researcher with France’s OCAPI program, which studies the management of human nutrient excretion — told Euronews that human urine could replace synthetic fertilizers….