PRI's The World Published by PRI's The World We need phosphate to grow food. But should we be digging it up from the sea floor? Listen Queue Download this audio Want to embed this player? Use the code below. More info. <iframe frameborder="0" scrolling="no" height="130" width="100%" src="https://www.wnyc.org/widgets/ondemand_player/wnyc/#file=/audio/json/669368/&share=1"></iframe> Share on Facebook Share on Twitter Email a Friend Most of the phosphorus used for crop fertilizer currently comes from phosphate rock on land, but those supplies are dwindling. An plan in Mexico for the world’s first underwater phosphate mine dredges up questions about priorities.