CF Industries (CF) Trading in Another Dimension

This old name from the portfolio, fertilizer stock CF Industries (CF) is trading as if it exists in another dimension.  I have to assume nitrogen prices are not feeling any effects from the global slowdown.  Amazing relative strength.

Mosaic (MOS) and Potash (POT) are not showing any similar sort of strength so it's not like its a broad move among the entire fertilizer space.  Head scratching.