I think it is possible that investors read the MF article and could not distinguish between Rentech (a terrible investment) and RNF (a wonderful investment). If this is the case the price will bounce around for awhile and start moving back up.
Management of the two entities is pretty much exactly the same, so not sure one can be so great and the other so terrible.
Apart from which, one fire or explosion (which are pretty common occurances at fertilizer plants) could make this 'wonderful investment' into a 'terrible investment' in a heartbeat. High risk here along with the reward.